A GUIDE TO MAINTENANCE CONDITION ASSESSMENT SYSTEMS

NCHRP Project No. 20-07, Task 206 COPY NO. A GUIDE TO MAINTENANCE CONDITION ASSESSMENT SYSTEMS Prepared for: National Cooperative Highway Research ...
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NCHRP Project No. 20-07, Task 206

COPY NO.

A GUIDE TO MAINTENANCE CONDITION ASSESSMENT SYSTEMS

Prepared for: National Cooperative Highway Research Program Transportation Research Board National Research Council Prepared by: Kathryn A. Zimmerman, P.E. and Marshall Stivers, P.E. Applied Pavement Technology, Inc. 115 W. Main St., Suite 400 Urbana, Illinois 61801

October 2007

A Guide to Maintenance Condition Assessment Systems

Table of Contents

TABLE OF CONTENTS CHAPTER 1: INTRODUCTION TO THE GUIDE ............................................................ 1 Overview...................................................................................................................... 1 Organization ................................................................................................................ 1 Audience...................................................................................................................... 2 Using The Guide.......................................................................................................... 3 Terminology ................................................................................................................. 3 CHAPTER 2: INTRODUCTION TO CONDITION ASSESSMENT SYSTEMS................ 4 Overview...................................................................................................................... 4 Forms of Condition Assessment Systems ................................................................... 4 Use of Condition Assessment Systems ....................................................................... 6 Benefits to the Use of a Condition Assessment System .............................................. 7 Organizational Issues to Address to Support the Condition Assessment System ....... 8 Links to Strategic Performance Measures ................................................................... 9 CHAPTER 3: ESTABLISHING A METHOD OF ASSESSING CONDITION ................ 10 Getting Started .......................................................................................................... 10 Differences in Output- and Outcome-Based Performance Measures ........................ 11 Developing a Condition Assessment System ............................................................ 11 Establishing Levels of Service ................................................................................... 17 Approaches to Rating Systems in Use Today ........................................................... 21 Tips for Success ........................................................................................................ 24 CHAPTER 4: CONDUCTING CONDITION ASSESSMENT SURVEYS....................... 25 Survey Options .......................................................................................................... 25 Survey Crews ............................................................................................................ 26 Quality Assurance/Quality Control Activities .............................................................. 27 Survey Forms ............................................................................................................ 27 Survey Frequency...................................................................................................... 27 Sampling.................................................................................................................... 28 Survey Equipment and Technology ........................................................................... 31 Obtaining and Maintaining Quality in CAS................................................................. 35 Tips for Success ........................................................................................................ 36 CHAPTER 5: USING RESULTS................................................................................... 37 Reporting Asset Conditions ....................................................................................... 37 Using Performance Targets to Establish Budget Requirements................................ 43 Using Condition Information in Programming Activities ............................................. 45 Tips for Success ........................................................................................................ 46 CHAPTER 6: IMPLEMENTATION................................................................................ 47 Implementation Approaches ...................................................................................... 47 Keys to Success ........................................................................................................ 48 Barriers to Overcome................................................................................................. 49 CHAPTER 7: SUMMARY ............................................................................................. 51 REFERENCES.............................................................................................................. 52 GLOSSARY OF TERMS............................................................................................... 55 Applied Pavement Technology, Inc.

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CHAPTER 1: INTRODUCTION TO THE GUIDE Overview Recent years have seen dramatic changes in the tools available to support the maintenance of transportation assets. In a 2005 survey conducted by the American Association of State Highway and Transportation Officials (AASHTO) Subcommittee on Maintenance, more than 52 percent of the respondents indicated that they have made changes to their maintenance management practices within the past 5 years (Zimmerman and Wolters). One such change is the increased use of enhanced condition assessment systems (CAS) to help identify maintenance needs, to measure progress towards achieving maintenance performance targets, to help monitor the effectiveness of operational activities, and to assist with the budgeting process. The enhanced approaches replace the existing systems used in many highway agencies with rating systems that allow agencies to quantify, for example, the amount of work needed to reach a targeted condition level for one or more assets. Today’s approaches also provide more information to support the budgeting process so that managers are better able to estimate resource needs and manage these resources appropriately. To support these types of business processes, and to take advantage of today’s technology, many highway agencies are revising their existing methods for collecting condition information. Whether an agency is revising an existing methodology or developing an approach to maintenance condition assessment for the first time, this Guide provides the information needed to make the changes. The information contained in this Guide is based on the experiences of Maintenance and Operations personnel from state highway agencies throughout the United States. Criteria for establishing a method of assessing asset conditions are presented along with information on how several agencies are routinely collecting this information. Some of the lessons learned in the design, development, and/or implementation of condition assessment systems are also presented in this Guide.

Whether you are implementing a new method of collecting condition information, or enhancing an existing system, this Guide will help you identify keys to success.

This Guide also introduces the use of condition information for establishing maintenance budgets and setting performance targets for performance-based budgeting activities. Key considerations in using the condition information in this way are presented. Organization This Guide is organized according to the following topics: •

Chapter 1: Introduction to the Guide. This chapter introduces the Guide and its contents.



Chapter 2: Introduction to Condition Assessment Systems. This chapter introduces the characteristics associated with today’s condition assessment techniques and how the condition assessment information can be used to support maintenance activities.

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Chapter 3: Establishing a Method of Assessing Conditions. Some of the key characteristics associated with establishing a method for assessing the condition of transportation assets are described.



Chapter 4: Conducting Condition Assessment Surveys. Procedures for collecting condition information are presented in this chapter, including information on survey frequency, sampling approaches, and equipment used.



Chapter 5: Using Results. This chapter introduces the use of the results of a condition assessment to report conditions, to set performance targets, and to support budgeting and programming activities.



Chapter 6: Implementation. Agencies can benefit from the lessons of others who have gone through the implementation process. This chapter introduces some of the keys to successful implementation and presents barriers to overcome.



Chapter 7: Conclusion. The final chapter summarizes the use of condition assessment tools in today’s Maintenance and Operations Departments and the benefits they can realize.



Appendices. The Guide also includes several appendices to serve as useful references now and in the future. Appendix A includes a glossary of terms and Appendix B lists some useful references.

Audience This Guide is targeted for State and local maintenance engineers, first-level maintenance supervisors (and higher), asset managers, and their industry counterparts. This content is most appropriate for individuals responsible for directing and managing maintenance operations and budgets, maintenance project and treatment selection, and/or the monitoring of system conditions. Potential uses for the information contained in the Guide are presented in table 1-1. Table 1.1 Potential uses for the Guide. Audience Upper Management First-Level Maintenance Supervisors State and Local Maintenance Engineers

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Potential Use This document serves as a guide to the use of condition information to establish maintenance investment levels and set performance targets. This document serves as a guide to help establish an enhanced method of assessing condition to help allocate resources and establish budgets needed to support strategic initiatives. This document presents the importance of an objective, repeatable method of assessing the condition of transportation assets to support maintenance activities and the information needed to develop a CAS that meets these requirements.

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Using the Guide This Guide is designed to be used as a reference at various points throughout an agency’s journey to adopt an enhanced condition assessment procedure. A user can read the entire Guide in one sitting, or refer to each applicable chapter as the implementation of the new procedure progresses. The appendices provide additional resources that may also be helpful at different stages of the implementation. Terminology Appendix A contains definitions for several terms that are used throughout the Guide. Please refer to this appendix if a term is unclear or to learn more about how the authors are using the term within this document. Perhaps most important is a description of what is meant by the term Condition Assessment System. As defined in Appendix A, a condition assessment is a physical inspection and rating of roadway assets to determine the condition of individual assets, roadway sections, or overall road networks. A condition assessment system involves all of the business processes that support the inspections, including the development of the methodology being used, the inspection procedures, the quality assurance processes, and the use of the data for other activities. Another term that is important to understand is Level of Service (LOS). Many agencies report the condition of assets in terms of a level of service that is being provided. In this approach, levels of service must be defined for each asset. In some cases, levels of service are reported in terms of letters similar to those used in a report card (such as A, B, C, D, and F). They may also be reported using a numerical system with “1” being the highest level of service and “5” being the lowest level of service. In general, LOS are defined in terms related to customer service, such as safety, convenience, aesthetics, comfort, or mobility.

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CHAPTER 2: INTRODUCTION TO CONDITION ASSESSMENT SYSTEMS Overview The maintenance of transportation assets is a critical component of a safe and efficient transportation network. Recognizing the importance of maintenance activities and their impact on the traveling public’s satisfaction with the road network, transportation agencies are placing a greater emphasis on the maintenance of existing assets than on building new assets that the agency can’t afford to maintain. At the same time, transportation agencies are forced to deal with increased pressures from outside sources (including politicians and the public) and more competition for funding. As a result, it is more important than ever that transportation agencies have a sound basis for making decisions and that all activities are performed as cost-effectively as possible. One of the keys to making sound decisions is having an objective and repeatable method of assessing the condition of transportation assets. This chapter introduces techniques for assessing asset condition so that the information can be used to support maintenance decision making. A summary of current practice in this area is also presented. More specific information on the techniques being used today is available in the next chapter on establishing a method of assessing condition. Forms of Condition Assessment Systems In 1999, a report published by the National Cooperative Highway Research Program (NCHRP) outlined the steps required to develop and implement a Maintenance Quality Assurance (MQA) Program (Stivers et al.). That report provides guidance based on workshops that were conducted under NCHRP Project 14-12, Highway Maintenance Quality Assurance. For many years, these resources served as the foundation upon which many state highway agencies structured their maintenance operations. Since these concepts were introduced, they have undergone continuing refinement to respond to the demands placed on today’s maintenance and operations personnel. As a result, maintenance managers are implementing tools that now provide them with the information needed for setting performance targets, linking customer expectations to work efforts and budgets, and evaluating system performance. The evolution of maintenance management is well documented in Guidelines for Maintenance Management Systems (AASHTO 2005). Some of the key differences between traditional ways of doing business and the enhanced capabilities of today’s systems are presented in table 2-1. These changes require that methods of assessing condition contain certain features that allow the information to be used for decision making. For example, many MQA programs use a rating process that evaluates system performance on a pass/fail system. Agencies using this approach establish performance criteria for each asset and conduct surveys to determine whether or not the

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asset passes the threshold condition. If not, the asset is reported as having failed. For example, criteria for catch basin and drop inlets might require that 90 percent of the opening of each inlet not be obstructed. For each catch basin and drop inlet inspected, the rater determines whether or not the specific inlet exceeds the threshold (in which case it passes). If not, the inlet is reported as having failed. Similar criteria are established for other maintained assets. Table 2-1. Differences between traditional and enhanced maintenance activities.

Type of Change Access to Information Information Used to Make Decisions Types of Performance Measures Used Importance of Customer Expectations Amount of Planning Conducted Preparation of Budgets

Traditional Approach to Enhanced Approach to Maintenance Activities Maintenance Activities All information processed Information accessed remotely through central office with new technology Subjective condition assessments More objective condition measures Output-based measures that Outcome-based measures that record accomplishments (such as report results achieved (e.g.,l time amount of material used) until a clear, snow-free surface is provided) Performance targets are more Performance targets are based on task oriented customer feedback and expectations More reactive More proactive Adjustments made to previous years’ figures

Budget needs estimated based on existing and targeted levels of service

In recent years, a number of agencies have implemented more detailed CAS that quantify specific asset deficiencies in terms of area, length, number, or percentage. Under this approach, an agency might report the percent obstruction in each catch basin or drop inlet. Other outcome measures might be used to represent the condition of other assets. For instance, an estimate of the number of pieces of litter in a certain sized area might be used for litter pickup, and the percent of guardrail that is damaged or missing might be used to indicate the current condition of the agency’s guardrails. Based on criteria established by the agency, a level of service can be determined for each sample inspected and for the group of assets. One of the greatest benefits to quantifying each deficiency is that an agency can more easily estimate the amount of work required to move an asset from one level of service to another. Information from the more detailed CAS can also be reported in terms of a pass/fail rating, if desired, by selecting a particular service level as the division between passing and failing. For example, if an agency uses 5 condition categories, the division between condition categories 2 and 3 might be established as the performance criteria for passing and failing. The development of a meaningful and repeatable condition assessment system is discussed in more detail in the next chapter.

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Use of Condition Assessment Systems There are a number of uses for the results of an enhanced condition assessment system, including the following: • • • • •

Reporting current conditions. Determining the funding needed to achieve a desired level of service. Setting maintenance priorities. Establishing performance targets. Deploying maintenance resources.

These and other uses of the results of condition assessments are discussed in more detail in chapter 5. Links to Transportation Asset Management As defined by the FHWA’s Office of Asset Management, transportation asset management is “a strategic process of maintaining, upgrading, and operating physical assets cost-effectively. It combines engineering principles with sound business practices and economic theory, and it provides tools to facilitate a more organized, logical approach to decision making” (FHWA 1999). One of the foundations to improved decision making is the availability of quality information about the assets being managed. This normally includes an inventory of assets providing descriptive and location information and a condition assessment so that current and future conditions can be determined. Therefore, the condition assessment procedures that are normally incorporated into MQA programs support an agency’s asset management practices and can lead to improved decisions regarding the allocation and utilization of agency resources. Maintenance activities support other agency initiatives since its programs provide services beyond system preservation. For example, maintenance and operations personnel are responsible for wildflower programs, adopt-a-road litter control programs, courtesy patrols, and other services that are directly related to the comfort and aesthetics so important to the traveling public. Current Practices In conjunction with the development of this Guide, a state survey was conducted to document condition assessment practices. The results of the survey are reported in detail in the final report for NCHRP Project 20-7/Task 206 (Zimmerman and Stivers 2007). The most effective CAS provide the information maintenance and operations managers need to report existing asset conditions, identify maintenance needs, set maintenance priorities, and evaluate trade-offs in resource allocation. Although there are several commonalities in the different CAS, there is a great deal of variability in the attributes that are being measured and the

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way that the condition assessment surveys are conducted. A summary of the most common CAS attributes is provided in chapter 3 of this Guide. The condition attributes are typically evaluated by district or regional personnel as part of a scheduled maintenance quality assurance survey. While many agencies collect the information annually, there are a number of agencies who collect condition information on some assets more frequently to account for seasonal variations. Most agencies collect some condition information using 0.1-mile representative samples, and then extrapolate conditions across the entire network. Since maintenance work programs are based on the results of the condition surveys, procedures to ensure the quality of the data are very important. Agencies emphasize the importance of annual training of the raters and independent checks of some subset of the data collected, such as 5 to 10 percent. Agencies also emphasize the importance of having adequate resources to support the CAS and reported that the surveys required 1 to 2 man-months of effort in smaller states, and more than 6 man-months of effort in larger states. Regardless of the size of the network on which the data are collected, it is important that the CAS be designed so that it can be managed with available resources, both now and in the future. The majority of transportation agencies that participated in the survey of practice reported that they have Maintenance Activity Guidelines in place that outline the work methods and resource requirements (in terms of equipment, materials, and personnel) for the maintenance activities most commonly performed using in-house forces. These guidelines are useful for estimating resource needs and for scheduling maintenance activities based on available resources. However, they assume a certain level of service is being provided and offer limited assistance in helping transportation agencies estimate the consequences of changing the level of service to meet customer demands and/or agency initiatives. Therefore, a number of agencies are building on these initial efforts to provide the information needed to evaluate different investment strategies. Four significant areas of development have been identified with respect to CAS based on the results of the state survey of practice. These are areas undergoing a significant amount of attention in state highway agencies. The development areas identified include: 1. The use of CAS information to establish performance targets that are linked to resource requirements. 2. The use of automated systems to estimate budgets and/or evaluate the impacts of different investment strategies. 3. The use of CAS results to schedule maintenance activities. 4. The establishment of stronger links between work priorities and customer expectations. Benefits to the Use of a Condition Assessment System Agencies that have used the enhanced approaches to assessing the condition of its transportation assets have benefited from the use of the data in supporting their decision processes. The availability of objective condition information provides a means of accomplishing the following:

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Establishing targeted condition levels for each asset within available funding levels.



Improving links between customer expectations and maintenance activities.



Understanding the cost of changing asset conditions from one level of service to another.



Establishing consistent conditions across an entire highway system.



Reassigning resources to under-performing assets.



Setting maintenance priorities on a statewide basis.

The use of this information to support the decision process has led to more consistent statewide conditions as a result of a better understanding by maintenance personnel of levels of service and by the use of performance targets to set statewide priorities. Organizational Issues to Address to Support the Condition Assessment System The development and implementation of a CAS represents a change in the way that business is conducted. Rather than continue to rely on subjective assessments of condition and reactive responses to perceived outside priorities, agencies have chosen to adopt a more objective CAS to help evaluate the effectiveness of the existing programs and to improve program accountability. However, the successful implementation relies on addressing the following organizational issues: •

Obtain upper-level support: Traditionally, maintenance budgeting has been based on historical expenditure levels and changes in available funding. In today’s organizations there is more demand for accountability from upper management and elected officials that requires that trade-offs in different investment options be considered and that the effectiveness of the program be quantified. As a result, many maintenance organizations have moved forward with the development and implementation of a CAS. Therefore, obtaining the support of upper management to support this endeavor is generally not difficult. Continued support from upper management demands that the CAS information is useful for evaluating the expected impacts of the agency’s investment options. In organizations where the implementation did not stem from upper management, the development and sustainability of a program such as this requires a champion who can communicate the expected benefits to upper management to secure resources while also securing the support of field personnel during the implementation.



Select a system that can be maintained: There are a number of differences in the complexity of the CAS being used by maintenance organizations. The selection of the most appropriate approach for any organization requires a careful assessment of how the results are expected to be used, the resources available to support the system, and the capabilities of the individuals who will be responsible for maintaining the system. In the end, it is most important that the CAS continue to be based on meaningful, current information. To reduce the resource requirements, agencies might limit the number of assets for which detailed condition information is reported or monitor conditions less frequently. Florida initially planned for four inspection cycles per year, but found that

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three were adequate. Other suggestions for tailoring the CAS are presented throughout this Guide. •

Provide resources needed to support the process: A variety of resources are required to maintain a CAS, including financial support for the on-going condition assessment surveys. However, the agency must also provide annual training to the individuals responsible for collecting the information and equipment (such as handheld data recording devices) to improve the efficiency of the data collection process. In many instances, the development and implementation of an enhanced CAS is conducted in conjunction with the implementation of a new maintenance management system, which would also require resources for developing or licensing software.

Recommendations for the implementation of an enhanced CAS are discussed in more detail in chapter 6. Links to Strategic Performance Measures A number of transportation agencies have identified strategic performance measures to establish a link between their strategic goals and the day-to-day business processes. One of the purposes is to energize their strategic management efforts, maintain focus, and enable organizational change (Cameron, Crossett, and Secrest 2003). Input from customers is an important consideration in setting strategic performance measures to address both external issues (such as mobility, congestion, and safety) and internal issues (such as system preservation and operations) (Cameron, Crosset, and Secrest 2003). These strategic performance measures can be monitored through the operational performance measures collected as part of a CAS. For instance, an agency might establish a strategic goal to provide a safe and efficient transportation system. While this goal might encompass a broad range of transportation systems, one of the strategic performance measures might include a target for the percent of the State Highway System that meets state standards. An objective condition measure such as the percent of guardrails that meet state standards, could be monitored as one of the traffic control devices being used to assess how well the agency is complying with its strategic targets.

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CHAPTER 3: ESTABLISHING A METHOD OF ASSESSING CONDITION Getting Started Moving forward to develop a new CAS is an exciting endeavor that will undoubtedly require a good deal of planning to ensure that the process provides the information needed to support the decision process within any resource constraints that may exist. To be most effective, a CAS should be designed to provide the types of information needed to support the agency’s decision process. This typically means thinking about how the results will be used to ensure that the right types of information are being collected. The following types of questions might help determine the type of CAS that is most appropriate in terms of data availability, complexity, and resource requirements. •

Will the information be used to assess asset conditions? What assets? What level of detail is needed?



How will the information be used in the budgeting process? Will it be used to assess needs? What maintenance activities will be focused on? Can resource requirements be linked to different levels of service?



What activities require the most resources in terms of funding, manpower, or other resources?



What information is already available to support this activity? Is there a complete inventory of transportation assets? Is there a universal method of referencing field locations? Are there on-going data collection activities that may be able to provide the information needed?

The answers to these questions will have a large impact on how the CAS is structured. For instance, an agency might start with a CAS for only those assets that consume the largest portion of the budget. By concentrating on these assets initially, an agency can significantly improve its budgeting decisions while limiting the data collection requirements to performance data that supports those decisions. Over time, additional assets can be incorporated into the process, as appropriate. Don’t underestimate the amount of time that should be spent on the planning process. The decisions that are made at this stage will influence the resource requirements to collect, process, and maintain the condition data. Therefore, it is important that each agency evaluate the tradeoffs between the resources required to collect and maintain the data versus the information that will be provided. There are at least three tools that are beneficial to have in place before implementing a new CAS. The availability of each of these tools is not mandatory to get started, but will provide useful information once the CAS is adopted. These tools include the following: •

An inventory of transportation assets that indicates the type of asset, general information about its dimensions and/or material properties, its location in the field, and the number

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of assets that have to be maintained. The location referencing system should be used consistently throughout the agency. •

Maintenance activity guidelines that identify the resource needs (in terms of labor, equipment, and material), production rates, work guidelines, and scheduling criteria for the major maintenance activities being scheduled.



An idea of maintenance priorities to address safety, operational, preservation, environmental, legal, and aesthetic requirements.

Differences in Output- and Outcome-Based Performance Measures There are a number of differences between the first generation maintenance management systems and the systems that many transportation agencies are adopting today. The newer maintenance management systems provide tools that allow agencies to evaluate the impacts of various investment options so that managers can be more proactive in scheduling maintenance activities. These systems estimate resource requirements to achieve targeted levels of service that may be based on customer expectations. One of the keys to the use of an enhanced maintenance management system is the availability of outcome-based performance measures that monitor the results achieved rather than the resources used. The latter type of performance measure is defined as being an output-based performance measure. Output-based performance measures are quickly being replaced by customer-oriented, outcome-based performance measures. Table 3-1 contrasts both types of performance measures for several service activities. To help evaluate whether your performance measure is outcome based, ask yourself whether it relates to something a customer might care about and/or whether it provides you with an idea of what needs to be corrected. For instance, the traveling public is much more interested in the percent of guardrail that is working as intended than in the amount of guardrail that can be fixed in an hour. Additionally, by recording the percentage of guardrail that does not meet the agency’s standards, the agency can quickly determine the amount of work required to improve the existing conditions.

To determine whether your performance measure is outcome-based, ask: 1. Does it relate to something a driver might care about? 2. Does it provide information about what work needs to be done?

Developing a Condition Assessment System Once the agency has identified how the results of the condition assessment will be used, you are ready to design your CAS. This section of the Guide will walk you through each of the major steps involved in identifying the assets that will be rated and developing performance measures for each asset that will be used to define levels of service. Details on conducting the surveys— including information on survey frequency, sampling, and equipment—are provided in the next chapter. This discussion assumes that an asset inventory has been established or estimated prior to the development of the CAS. At a minimum, the inventory should provide sufficient information to

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describe the basic asset attributes and their location. The type of attributes typically collected for each type of asset is presented in table 3-2. Table 3-1. Examples of output- and outcome-based performance measures.

Asset Guardrail Highway lighting Ditches Pavement Mowing

Sample Output-Based Performance Measure Number of miles straightened in 1 hour Number of bulbs replaced per month Linear feet of ditch maintained Tons of material used per mile to fill potholes Number of acres mowed per day

Sample Outcome-Based Performance Measure Percent not performing as intended Percent of highway lights malfunctioning Percent of ditches greater than 50 percent blocked or filled Number of potholes per mile Average grass height

Selecting the Assets to Include It is often a challenge for agencies to select which assets should be incorporated into the condition assessment surveys. The natural inclination is to include as many assets as possible. However, it may be a better use of resources to reduce the number of assets being surveyed to those that are most important or those that consume the largest portion of the maintenance budget. Over time, additional assets can be added as maintenance personnel become familiar with the assessment process. Having too much data to collect may overwhelm the individuals responsible for the survey, which in turn can lead to errors in the data. A formal process for selecting assets to incorporate into your CAS is discussed in the AASHTO Asset Management Data Collection Guide. It suggests using the following selection criteria to direct your initial data collection efforts (AASHTO 2006): •

Are there established protocols (such as standard procedures or guidelines) for the data collection activities? If yes, are these protocols being used? If no, why not?



What is the relative quantity and dollar value of the asset compared to those of the entire asset population?



What is the importance of the asset to the agency and road users (does it address safety, congestion, environmental, or aesthetic goals)?



How easy is it to collect data for this asset?



Are there automated procedures or tools for data collection?



How frequently do the data need to be collected?



How important is the accuracy of the data for the asset? Are high-quality data required?

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Table 3-2. Basic inventory attributes (from AASHTO 2006). Type of Attribute Location

Inventory Attribute Point Asset Linear Asset Direction

Physical

Type Linear Dimension

Customer Use

Assets described as having a start and end point Travel lane direction A descriptor to help identify the asset in more detail Physical dimension of an asset, which may not be appropriate for all assets

Size/Area

The size of the asset or the space that the asset occupies

Material

The material used to construct the asset The quantity of the asset within a particular location For buried assets, the depth of earth or cover above the asset Date when the asset was last put in service or date of last major maintenance action

Number

Historical

Attribute Description Assets described by a single point of location

Depth of Cover Install Date History Traffic

The traffic count or number of customers directly served by the asset

Examples of Applicability Culverts, drop inlets, signals, signs, impact attenuators, lighting, and rest areas Sidewalks, ditches, fences, guardrail, shoulders, paved surfaces Sidewalk, paved surfaces, fence, sign Culvert, curb & gutter, ditch, shoulders, signs Culverts, curb & gutter, sidewalk, ditch, fence, sound barrier, shoulder, paved surfaces, bridge, pavement marking, guardrail Culvert, grass mowing, brush, litter, landscaping, retaining wall, sign, paved surfaces Fence, sound barrier, pavement marking, guardrail, shoulders Culvert, drop inlet, signs, pavement markers Culverts Most assets, with the exception of brush, mowing, or landscaping Paved surfaces, signals, signs, pavement markings, guardrail

By assigning a weighting factor to each question and scoring each asset on a scale from 1 to 5 (with 5 representing a high impact), a weighted average can be determined for each asset. The results can be prioritized so that the most important assets (those with the highest scores) can be quickly identified. In most cases, assets that receive a large proportion of the maintenance expenditures (such as pavements and bridges) or assets that contribute to safety considerations (like guardrail and regulatory signs) will score highly using this type of approach. Assets that are difficult to assess in the field, assets with no standard process for assessing conditions, or assets that are primarily maintained for aesthetic purposes tend to score lower in this process. Assets are normally categorized into maintenance groups or elements based on their common characteristics. The most common asset categories and associated asset types are presented in table 3-3. Each agency should adapt the list as appropriate for the road network being maintained. For example, urban areas may add assets such as sidewalks, manholes, and bus stops to the listing.

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Table 3-3. Commonly used asset categories and asset types. Asset Category Drainage Structures

Roadside

Pavement Bridges and Other Structures Traffic

Special Facilities

Asset Types Culverts Curb & Gutter Ditch/Slope Drop Inlet Underdrain & Edgedrain Fence Grass Mowing Brush Litter Landscaping Sound Barrier Paved Shoulders Unpaved Shoulders Paved Surfaces Bridges (which may be subdivided into substructure, superstructure, deck, rails, and joints) Signs (ground and overhead) Pavement Marking Pavement Marker Guardrail Guardrail End Treatment Impact Attenuator Highway Lighting Signals Rest Areas Tunnels Weigh Stations

Defining Performance Characteristics Perhaps the most challenging aspect of designing the CAS is selecting the performance characteristics that will be used to rate each asset. As discussed earlier, the most effective performance characteristics will be outcome-based so the evaluation focuses on the conditions impacted by maintenance activities rather than a rating of the quality of the maintenance activities themselves. As you identify key performance characteristics for each asset, it is often easiest to think about the performance features or characteristics that are improved by performing key maintenance activities (Stivers et al. 1999). For example, sign repair and replacement keeps signs plumb and visible under both daytime and nighttime conditions. Therefore, a performance characteristic for signs might include the retroreflectivity of the sign at night and/or whether the sign post is plumb and unbroken. Similarly, guardrail repairs are performed to keep the guardrails functioning as

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intended. Therefore, the percent of guardrails that are functioning as intended might be used as a performance characteristic. Maintenance performance characteristics may also be based on customer expectations obtained through customer surveys, focus groups, or some other approach. There are a number of resources available to assist an agency in gathering this type of information (Stivers et al. 1999 and Hyman 2004). Table 3-4 lists the performance attributes most commonly used by state highway agencies based on a survey of state practice conducted in 2006. Table 3-4. Commonly used performance attributes. Asset Type Drainage Culverts Curb and Gutter Ditches Drop Inlets Underdrains Roadside Fence Grass Brush Litter Pavements Paved Shoulders Unpaved Shoulders Paved Surfaces

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Attributes Clogged or interrupted flow Structural deterioration Structural damage or deterioration Settlement Interrupted flow Inadequate drainage due to settling or debris Eroded flowline Blockage Broken/missing grate Structural deterioration End protection damage Pipe blocked or crushed Length of fence (or fabric) damaged Length of broke posts Grass height Obstructions Encroachment on travelway Volume within a certain length Appearance Drop-off Structural distress Drop-off Build up Structural distress Cracking Faulting Functional distress Roughness Page 15

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Asset Type Traffic Items Signs Pavement Markings Pavement Markers Guardrail Guardrail End Treatments Impact Attenuators

Special Facilities Rest Areas

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Attributes Post or panels damaged Pole or post plumb (or orientation) Visibility at a standard distance (or legibility) Day visibility Missing or damaged marking Night retroreflectivity Number of missing, damaged, or nonreflecting Obstruction Post or rail damage Orientation Functionality Post or rail damage Length functioning as originally intended Structural integrity Damage Functionality Percent operational Graffiti Facilities working properly Appearance Mowing Landscaping Odor Cleanliness

There is often a tendency to identify more characteristics than are actually necessary for monitoring performance and estimating maintenance needs. Especially in the initial stages of the CAS development, an agency should concentrate on collecting the most detail on the activities associated with the greatest expenditure of maintenance funding. By identifying performance characteristics that link to the high-resource activities, the CAS can have the greatest impact on improving the effectiveness of maintenance decisions. The features that are selected as part of a CAS tend to vary by agency. Each feature is rated in accordance with threshold conditions established by the agency. These conditions are typically described in a handbook or guide to help ensure consistency in the ratings. The handbooks normally identify the element, describe the threshold conditions, indicate how distress should be measured, and present photographs of different condition levels to help clarify the ratings to the raters. A sample of a page from the Inspection Manual for the Maintenance Management Quality Assurance Plus process used by the Utah Department of Transportation is provided as figure 3-1. Note that the example indicates the method used to measure performance (linear feet

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of deficient fence), the frequency with which performance will be measured, the methodology for collecting the information, and a description of how deficiencies shall be identified.

Figure 3-1. Sample page from Utah DOT’s Inspection Manual (Utah DOT 2006). Establishing Levels of Service The next step in developing the CAS is to define the LOS ratings. This step is very important because the resulting ratings serve as the basis for reporting existing conditions and estimating maintenance work requirements. There are two approaches that are generally used to establish LOS: the pass/fail approach and the graded approach. These two approaches can easily be confused because grades can be determined for an agency using the pass/fail approach and a pass/fail rating can be determined if an agency is using the graded approach. The primary difference lies in the level of detail collected in the field and the use of a threshold value in

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establishing the LOS. The differences in the two approaches are illustrated graphically in figures 3-2 and 3-3. Set threshold targets triggering maintenance activities

Conduct field survey and record whether each segment passes or fails based on the criteria

Match conditions to acceptable level of service established by the agency

Sample mowing standards: No more than 2 percent of vegetation exceeds _______ inches. Use 18 in for urban limited access highways, 12 in for urban arterials, and 20 in for rural highways.

Aggregate the survey results and determine the overall level of service. Additional resources are needed if an acceptable level of service is not provided

Figure 3-2. Pass/fail approach to determining LOS. Set performance criteria for different levels of service

Conduct field survey and record the number (or percentage) of deficiencies in each segment

Calculate the LOS based on the information obtained from the field survey

Determine needs by comparing actual to targeted LOS

Sample performance criteria for pavement markers: percent damaged or missing.

Record the total number of markers and the number damaged or missing

Sample LOS for pavement markers: A = 2 percent damaged or missing B = 5 percent damaged or missing C = 8 percent damaged or missing D = 13 percent damaged or missing F = >13 percent damaged or missing

Figure 3-3. Graded approach to determining LOS.

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Pass/Fail Approach Figure 3-2 illustrates the pass/fail approach. In this approach, thresholds are established for each performance criteria that indicate when corrective action should be taken. In the example shown, a section fails if more than 2 percent of the section has grass that exceeds the height criteria. The same approach can be used for other assets, too. For instance, ditch cleaning might be required if more than 15 percent of the section is at least 50 percent filled with debris or sediment. Pothole patching could be triggered when potholes reach a certain defined size. Using these condition thresholds, an acceptable condition standard is established for the network. This standard, which can vary based on functional class, funding source, geographic location, traffic volume, or other measure, provides an indication of what level of service is acceptable to the agency. For instance, the agency might consider an acceptable LOS on the interstate as having 95 percent of the guardrails functioning as intended. On the primary highways an acceptable condition might be defined as 90 percent of the guardrails in acceptable condition. This approach is fairly easy to implement and the required data collection is relatively quick. It generates useful information for maintenance budgeting activities, provided that the condition thresholds do not change from year to year. Florida DOT is an example of an agency that has been using this approach successfully for a number of years. Graded Approach In recent years an increasing number of agencies have begun using the graded approach for establishing LOS. Under this approach, which is illustrated in figure 3-3, different condition thresholds are established to represent different levels of service. In the field, highway segments are evaluated and assigned a LOS based on the reported deficiencies identified in the field for each asset. In the example provided in figure 3-3, the percent of damaged or missing pavement markers are reported in each segment. Using criteria established by the agency, a LOS can be established. Similar types of criteria must be developed for each asset being evaluated. For instance, a performance measure for pavement striping might be established as the percent of pavement striping that is worn or missing. The measured or estimated quantity of worn or missing striping identified in the field is then used to determine a LOS. The following service levels might be used for pavement striping maintenance: •

Level A (Highest): 0 to 1 percent worn or missing.



Level B: 1.1 to 5 percent worn or missing.



Level C: 5.1 to 10 percent worn or missing.



Level D: 10.1 to 15 percent worn or missing.



Level F (Lowest): Greater than 15 percent worn or missing.

During the field surveys, the actual quantity of striping that is worn or missing is recorded so a LOS can be determined. As with the pass/fail approach, information from the survey can be aggregated for each maintenance element or category on a statewide (or other) basis.

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The LOS information obtained from this approach can also be reported in pass/fail terms by selecting a LOS break as the threshold. For example, pavement sections in a LOS category D or F could be reported as failing to meet the agency’s performance criteria if the division is established between levels C and D. Ideally, all pass/fail criteria using this approach are set at the same point. In other words, if criteria are defined so that the division between levels C and D is used to distinguish acceptable and unacceptable conditions for one asset, the same approach should be used for other assets, too. The primary advantage to the added level of detail associated with this approach is that maintenance budgeting requirements associated with changes in condition thresholds can be estimated more easily. In the previous example, the agency could easily estimate the amount of work associated with a change in the performance criteria if, instead of setting the break between levels C and D, the break was established between levels B and C. The North Carolina, Washington, and Utah DOTs are examples of agencies using the graded approach. Recommendations for Developing LOS There is no single approach to developing LOS that will meet the demands of all transportation agencies. Therefore, it is imperative that each agency spend some time developing an approach that provides the type of information needed without exceeding resource constraints. Specific recommendations that might help in developing LOS are provided: •

Establish a committee of both field and central office personnel to develop the LOS thresholds. The literature recommends a committee comprised of approximately 25 to 30 people, consisting of approximately 75 percent field personnel and 25 percent central office personnel (Stivers et al. 1999).



It can be less labor-intensive to rate some assets in terms of whether they are performing as intended rather than record specific deficiencies. A level of service may be established based on the percentage of the specific asset(s) performing as intended for certain assets. Measured deficiencies may be used for other assets.



Select a sampling frequency that is statistically valid and balances the need for reliable maintenance condition information with the resources available for collecting the information. This topic is discussed in more detail in chapter 4.



Threshold values for either approach can be varied based on a variety of factors, such as functional classification, funding source, geographic location, or traffic volume.



For safety considerations, an intervention point should be set early enough that a maintenance activity can be scheduled before a deficiency becomes a legal issue (Stivers et al. 1999).



A technique must be developed to aggregate the information from the field into meaningful information with which decisions can be made. This is especially true if multiple performance characteristics are used for a single maintenance activity (such as pavements, where multiple distress criteria may be established) or if a single LOS is desired across all maintenance categories. In other words, if a single rating is desired that considers drainage structures, roadside assets, pavements, bridges, traffic, and special

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features, a process for combining the individual scores must be developed. This is discussed in more detail in chapter 5 in the section on reporting asset conditions. •

Train the individuals who will be responsible for conducting the surveys so they understand the performance criteria being used. Most agencies have survey manuals that clearly describe the threshold conditions for each feature and the way that any deficiencies should be recorded.



Before implementing the CAS on a statewide basis, pilot the procedures for a small area to determine whether it provides reliable information without straining resources. Some adjustments to the process may be needed once the raters have an opportunity to evaluate how easy it is to measure the deficiencies and/or how much time the process requires in the field.

Information on conducting the field surveys is discussed in more detail in chapter 4. Chapter 5 presents information on compiling the results of the surveys to report asset conditions on a network basis. Other uses of the information are also presented in chapter 5. Approaches to Rating Systems in Use Today Throughout this chapter, examples of performance criteria and level of service definitions have been provided. Additional examples are provided in tables 3-5 through 3-8, which present LOS criteria used by North Carolina and Washington State DOTs for reporting network conditions. Table 3-5 presents LOS criteria for drainage structures, table 3-6 for roadside and vegetation management, table 3-7 for pavements and shoulders, and table 3-8 for traffic features. While the tables are not inclusive of all transportation assets, they provide a number of examples to illustrate the use of the graded approach. Examples of the condition thresholds for several agencies using the pass/fail approach are available in the literature (Stivers et al. 1999). For example, table 3-5 provides LOS descriptions for drainage structures in both Washington State and North Carolina. Using the Washington State criteria for ditches, if more than 15 percent of the survey segments have ditches that are filled (defined as more than 50 percent filled with sediment or debris) the LOS category reported would be “F.” Similarly, if only 4 percent of survey segments had ditches that were filled, the LOS category would be “B.”

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Table 3-5. Sample LOS descriptions for drainage structures (WSDOT 2004 and NCDOT 2000). Asset

Performance Measure

Ditches Washington

% greater than 50% filled with sediment or debris North Carolina Blocked ≥ 50% and not functioning as intended Culverts (or Crossline Pipe) Washington % greater than 50% filled or otherwise deficient North Carolina Blocked ≥ 50%, or damaged Slopes Washington % of centerline miles with slides or erosion encroaching on, or undermining the shoulder or traveled way North Carolina Failures ≥ 1 foot wide

A

B

LOS Category C

D

F

0 – 1%

1.1 – 5%

5.1 – 10%

10.1 – 15%

> 15%

2%

6%

9%

12%

> 12%

0 - 2%

2.1 – 5%

5.1 – 10%

10.1 – 20%

> 20%

1%

3%

4%

6%

> 6%

0–2%

2.1 – 4%

4.1 – 7%

7.1 – 10%

> 10%

1%

2%

4%

6%

> 6%

Table 3-6. Sample LOS descriptions for roadside and vegetation management (WSDOT 2004 and NCDOT 2000). Asset

Performance Measure

Litter Washington

Number of fist sized, or larger, objects present per centerline mile North Carolina Number of pieces ≥ fistsized Brush & Tree Control Washington % of centerline miles with instances of vegetation obstructions North Carolina Within 15 feet above, 10 feet back of ditch/shoulder Mowing Washington N/A North Carolina Average grass height

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LOS Category C

A

B

D

F

0 – 125

126 - 250

251 - 500

501 1000

> 1000

25

56

100

190

> 190

0 - 0.5%

0.6 – 1.5%

1.6 – 3.5%

3.6 - 6%

>6%

2%

7%

12%

17%

>17%

6 in

8 in

10 in

14 in

> 14 in

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Table 3-7. Sample LOS descriptions for pavements and shoulders (WSDOT 2004 and NCDOT 2000). Asset

Performance Measure

Pavement Maintenance Washington Square foot of deficiencies per lane mile for patching and repair Linear feet of pavement with unfilled cracks/joints per lane mile for crack sealing North Carolina Pavement condition rating (0 to 100 scale) Shoulder Maintenance Washington % of paved shoulder area with deficiencies North Carolina High shoulders ≥ 1 inch Low shoulders ≥ 2 inches Sweeping and Cleaning Washington Percent of paved shoulder area with debris North Carolina N/A

A

B

0 - 1000

1001 2000

0 - 250

LOS Category C

D

F

2001 5000

5001 – 10,000

> 10,000

251 - 500

501 1000

1001 2500

> 2500

98

93

86

70

< 70

0-2%

2.1 – 4%

4.1 – 8%

8.1 – 15%

>15%

1% 1%

4% 5%

6% 8%

10 11%

> 10% > 11%

0 – 5%

5.1 – 10%

10.1 – 20%

20.1 – 40%

>40%

Table 3-8. Sample LOS descriptions for traffic features (WSDOT 2004 and NCDOT 2000). Asset

Performance Measure B

Percent of pavement striping worn or missing Worn, missing, or obliterated

0 – 1%

1.1 – 5%

5.1 – 10%

2%

4%

7%

% of regulatory signs that are unreadable at night Illegible, missing, or obliterated

0-2%

2.1 – 5%

5.1 – 10%

1%

3%

Percent of guardrail that is damaged or missing Damaged, not functioning as designed

0 – 1%

Number of repairs per signal system required for this type of malfunction. Preventive maintenance is NOT counted N/A

Pavement Striping Washington North Carolina Regulatory Signs Washington North Carolina Guardrails Washington North Carolina Traffic Signals Washington

North Carolina

LOS Category C

A

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D

F

10.1 – 15% 10%

>15% >10% >20%

5%

10.1 – 20% 7%

1.1 – 3%

3.1 – 5%

5.1 – 10%

>10%

1%

2%

4%

6%

>6%

1 per 2 years

1 per year

2 per year

3 per year

4 per year

>7%

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Tips for Success There are numerous benefits associated with the development and implementation of a CAS. Agencies report that conditions become more consistent on a statewide basis, presumably because field personnel better understand performance criteria and maintenance priorities. Based on the feedback from agencies that have adopted these techniques, the following recommendations are provided to improve the effectiveness of the program. •

Tailor the performance criteria to reflect factors that trigger the need for maintenance activities.



Concentrate initially on those assets that have the largest impact on the maintenance budget or the greatest impact on the safety of the traveling public.



Keep the system as simple as possible without sacrificing the quality of the information provided. This requires a balance between the need for information and the complexity of the system. The decisions made at this level have a significant influence on the amount of time that will be required in the field.



Seek the input of field personnel in developing the performance factors and levels of service. These individuals are most familiar with the factors that trigger maintenance activities and their involvement goes a long way towards obtaining buy-in of the program.



Study the information available from other states and use it to help guide your system development.



Provide adequate training to those who will be responsible for providing data.



Provide clear descriptions of performance criteria so the results are repeatable.

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CHAPTER 4: CONDUCTING CONDITION ASSESSMENT SURVEYS Survey Options The information used to report conditions and to estimate maintenance budgeting needs is based on the results of field surveys typically conducted by maintenance personnel. Therefore, it is important that the survey procedures are well defined to reduce variability from one rater to another (or from year to year). Also, it is important that the field personnel have adequate time to collect the information needed and are provided with the equipment needed to conduct the surveys efficiently. If field personnel are rushed to complete the surveys, or don’t understand the importance of the results, it is likely that the quality of the survey will suffer. There are a number of options available to help tailor the condition assessment surveys to match the resources available for this activity. One of the first decisions is whether the survey will be conducted entirely through manual surveys, or whether automated equipment will be used to collect a portion of the data. Most agencies collect the information manually using 2-person crews who conduct the surveys while they walk over the inspection segment. Where automated equipment is used, it is normally associated with a collaborative effort with other on-going data collection activities such as pavement management. Safety is an important consideration and care should be taken to protect the survey team as much as possible. If manual surveys are used, crews typically wear protective equipment (e.g. safety vest and foot protection) and walk towards traffic if they are near the traveled lanes. Safety vehicles may also be used to alert on-coming vehicles that maintenance personnel are working in the area.

There are many options to consider when designing your CAS. The agency must decide the following: 1. Will a manual survey be conducted? 2. How frequently should the survey be conducted? 3. Will the entire network be surveyed or will a sampling approach be used? 4. What size samples will be inspected? 5. Will maintenance crews survey their own areas of responsibility? This chapter will help you answer these questions.

Another important decision concerns the extent of the pavement network that will be surveyed. In small states, condition assessment surveys may be conducted over the entire network. However, in larger states resource limitations may require that the agency use a sampling method to collect condition data. Under a sampling approach, a representative portion of the network is inspected and the results are extrapolated to represent the conditions of the entire network. A statistical analysis is used to determine the number of samples that must be inspected to be representative of the entire population. If a sampling approach is to be used, an agency must also define the size of the samples that will be inspected. A fixed sample size is used for consistency. The majority of state highway agencies are using 0.1-mile sections for collecting maintenance condition information, but 0.2mile, 0.3-mile, 0.5-mile and 1-mile segments are also used.

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It is also important to assign responsibility for the conduct of the surveys on a regular basis. The frequency with which these surveys are conducted varies, although most agencies collect the information annually. As discussed in a later section, some agencies collect the condition data more frequently than annually to capture seasonal variations in conditions. The agency must also decide whether the surveys will be conducted by region or district personnel in their own area of responsibility, or whether field crews will conduct surveys in neighboring areas to avoid rating conditions under their direct control. Alternatively, central office personnel could be given responsibility for conducting the surveys. Some agencies choose one of the two latter approaches as a way to avoid possible conflicts of interest. This consideration may be especially important if the results of the survey are used to allocate maintenance funding or to evaluate the performance of maintenance personnel. These and other considerations in conducting condition assessment surveys are discussed in more detail within this chapter. Additional information on combining the survey results to determine an overall LOS is presented in chapter 5. Survey Crews The majority of maintenance condition assessment surveys are conducted by the district or region personnel most familiar with the features being rated. In some cases, central office maintenance personnel are involved in the surveys and a few agencies use consultants to collect the information. Each field crew typically consists of at least two people, with at least one individual having experience in developing or conducting the condition surveys to help ensure consistency. Each year the field crews should participate in training as a further step towards ensuring consistency and accuracy on a statewide (or agency-wide) basis. Some agencies prefer that maintenance personnel rate assets outside their direct responsibility to avoid the potential conflicts of interest that may arise. If this is an issue, an agency might consider having the field crew rate assets in a neighboring area or forming survey teams that include one member from an adjacent area. Each individual on the rating team should conduct an independent evaluation of the features being inspected in accordance with the performance criteria established. Once each of the raters has completed the inspection of a segment, the two raters should discuss their ratings until a consensus can be reached and the data can be officially entered on the form. If raters are very experienced, rather than duplicate each others’ ratings they may each rate certain assets and combine their ratings onto the official form. If a sampling approach is used, it is important to mark the beginning and end point for each sample and its site number. This allows the crew to return to the same sample should a question arise in the future, but also helps the crew stay within the sample area if several passes through the survey segment are required to adequately assess each feature. The field crews should wear protective equipment (e.g. safety vest and foot protection) and walk towards traffic if they are near the traveled lanes. Safety vehicles, signage, and/or flagging may

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also be used to alert on-coming vehicles that maintenance personnel are working in the area. The survey vehicle should be safely parked along the side of the road with strobe lights and flashers activated. Quality Assurance/Quality Control Activities The quality of the data collected is very important to the reliability of the condition information. Therefore, it is important that quality control (QC) and quality assurance (QA) procedures be developed. QC procedures help to control the quality of the data being collected. Training of the survey crews prior to each survey is the most commonly used QC approach being used. Many agencies perform QA checks on the data before accepting the survey results. A number of different forms of QA checks can be used, including comparisons of the data from one year to another or independent checks of the data. If independent checks of the data are used, it is recommended that an independent rater verify the ratings in a fixed percentage (such as 5 to 10 percent) or minimum number (25 is suggested in the literature) of the samples surveyed (Stivers et al. 1999). The independent rater(s) could be pulled from a different district or the central office. While annual checks of the data may be sufficient, more frequent attention may be required if certain teams are having problems producing accurate and consistent ratings (Stivers et al. 1999). QA inspections should verify that the appropriate assets have been rated and that the ratings are accurate. A process for using statistics to verify the accuracy of the ratings is provided in the literature (Stivers et al. 1999). Survey Forms Each agency should develop a process for quickly recording the information from the field so it is available to support decisions as soon as possible. Many agencies develop customized forms for recording the information, although many agencies are automating these forms to reduce the number of times data has to be recorded. Whether a paper form or automated form is used, it should contain general information about the segment being inspected and a listing of the features/characteristics that are to be rated. A copy of the rating form used by Washington State DOT is provided as figure 4-1. Survey Frequency Each agency must establish a survey frequency that balances the need for reliable maintenance condition information with the resources available for collecting the information. Because of the importance of the information for setting maintenance budgets, many agencies collect this information at least annually. Where seasonal variations in data may effect budgeting requirements, surveys may be conducted two, three, or four times a year to capture these changes (in vegetation growth for example). The condition of some assets, such as rest areas, may change so frequently that these assets are monitored at least weekly to ensure that the desired level of service is maintained.

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Figure 4-1. Sample inspection form (WSDOT 2004). Sampling In large transportation agencies it is not feasible to collect condition information on all of the assets maintained by the agency. In these instances, agencies have developed a method for randomly selecting samples to be inspected as part of the condition assessment process. Since the samples are randomly selected, they are assumed to be representative of the entire population and can be used to estimate the overall condition of the total population of assets. During the Maintenance Quality Assurance Peer Exchange held at Madison, WI in October 2004, several specific statistical questions related to MQA programs were raised. In response, the Midwest Regional University Transportation Center and the Department of Civil and Environmental Engineering at the University of Wisconsin, Madison prepared a Guide to the use of statistics in MQA programs (Schmitt et al. 2006). That Guide is an excellent resource for agencies interested in more detail on this topic.

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As stated earlier, during the conduct of a survey in which samples are used, sample start and end points are often marked so the crew can go back if issues arise after the surveys are completed. Sample Size Agencies must select a sample size for inspection purposes. Although sample size varies by agency, most sample sizes range from 0.1 mile to 0.5 miles in length. According to responses to the survey conducted as part of this project, almost 55 percent of the participants used a 0.1-mile length, while another 10 percent use a 0.5-mile length and 20 percent use a 1-mile length. Other agencies use 0.2-mile or 0.3-mile samples according to the survey. In practice, it is generally easier to inspect smaller samples since there are a lot of details that need to be noted in each sample. Smaller samples require less time to inspect, although the agency will have to inspect more samples if a small sample size is used (since there will be more small samples in a network than long samples). There is also a greater possibility that some features will be missing from some of the randomly-selected samples. If an agency uses longer samples, there may be more variation in asset condition within each sample. However, longer samples have a greater chance of including each of the various assets that are being rated. In the end, each agency must decide the sample length that works best for their crews. Selecting Samples For Inspection Under a random sampling approach, each section in the roadway network has an equal likelihood of being selected for assessment. To select a random sample: •

Determine the total number of samples in the population.



Determine how many samples need to be inspected to be representative (see below).



Use a random number generator or other approach to select samples to be inspected.



Adjust the samples as necessary to avoid samples containing bridges or other structures (randomly identify extra samples to use as alternates).

The number of samples that must be inspected to achieve the desired precision and confidence level can be determined using the following formula (Stivers et al. 1999): n = (z2*s2)/d2 where: n s d z

= required number of samples to inspect. = expected standard deviation of the ratings. = precision (for a precision of ± 5 points on a 1 to 100 scale, use a value of 5). = z-statistic (for 95 percent confidence, use z = 1.96).

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Guidance on establishing the expected standard deviation and precision values is provided in the literature (Stivers et al. 1999 and Schmitt et al. 2006). The latter of the two references reports that a number of states use confidence levels of 90 to 95 percent and precision values ranging from 3 to 6 percent. In general, the higher the degree of precision desired or the higher the standard deviation, the greater the number of samples that need to be inspected. Adjustments to the samples are made if a bridge or other structure is located in the randomly selected sample, as described later in this chapter. What if a sample doesn’t contain all the assets we are rating? Because of the random approach used to select samples to inspect, there is no guarantee that all samples will contain every asset being inspected. For instance, one sample may contain no guardrail or inlets while another sample may include several. This should not cause any problems with the rating process; the raters should simply mark that the particular asset being rated is not present in the sample. If multiple assets are present, either the rater should rate each asset separately or the assets should be assumed to be combined as a single asset. The correct approach will depend on the type of rating procedure being used. What if there is a “problem” with a randomly-selected sample? If there is any type of problem with a randomly-selected sample which affects its ability to represent overall conditions, most agencies elect not to survey the location and select a different sample to inspect. Examples of these problems include the road being under construction or having a portion of the road segment be on a bridge structure. Stratification With random sampling, there is no guarantee that samples will be identified in each district or region maintained by the agency. To ensure that there are representative samples in each region, agencies can divide the network into subsets based on geography (such as an individual district or region) or facility type (such as functional class or highway system) (Stivers et al. 1999). The number of samples within each subset is determined and the number of samples to be inspected within that subset is calculated using the equation provided earlier. This is referred to as a stratified random sample. According to NCHRP Report 422, at least 25 samples per subset should be inspected and no more than 10 subsets should be created (Stivers et al. 1999). The South Carolina DOT stratifies its samples by highway system so that samples will be identified on the Interstates, Primary Roads, and Secondary highways. Other agencies stratify their system by county or district to ensure that a representative number of samples are selected in each geographic area. After strata have been defined, the number of samples in each stratum should be determined using the equation provided in the previous section. As a minimum, 25 segments per stratum should be sampled, regardless of the number of segments calculated using the sample size

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equation (Stivers et al. 1999). Be sure to use the standard deviation computed for each stratum in calculating the number of segments to inspect since each stratum will have a unique sampling error (Stivers et al. 1999). Survey Equipment and Technology There have been tremendous advances in technology within the last few years that have greatly influenced the way condition information is being collected, stored, and reported. Today, many agencies take advantage of handheld computers, handheld voice recorders, global positioning satellite (GPS) units, and other technology to locate assets and record condition information. AASHTO recently published an excellent reference on this subject (AASHTO 2006). The document presents guidelines for conducting data collection activities associated with most assets normally incorporated into a MQA program. Typical Survey Equipment and Supplies The following list represents the types of equipment normally carried by a survey crew conducting condition assessment surveys: •

A copy of the condition assessment manual or guidelines.



Vehicle equipped with distance measuring instruments (DMI) and safety lighting.



DOT-approved vests, rain suits, and footwear.



Clipboard, pencils, erasers, paper clips.



Rating form or handheld data entry device.



Maps or straight-line diagrams of the segments being sampled.



Measuring wheel and/or measuring tape, ruler.



Leveling device (such as carpenter’s level or string level).



Handheld laser range finder.



Paint



Hammer and nails.



Heavy-duty pry bar (for removing covers or grates).



Bush axe.



Pocket calculator.



First aid kit.

Manual and Mobile Data Collection Techniques There are two primary approaches that are used to collect asset condition information: manual approaches and mobile approaches (AASHTO 2006). Manual approaches can take a number of

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forms, but are generally conducted by walking (or riding a bicycle) the length of an entire sample. Survey crews are equipped with distance measuring devices, equipment for recording condition information, and location referencing devices (such as GPS units). An example of the type of handheld technology currently being used during manual surveys is presented in figure 42.

Figure 4-2 Handheld computer with camera, GPS, recorder, and touch entry. With the changes in technology that have occurred within the last several years, more and more agencies are taking advantage of mobile technology to record condition information. An example of this type of equipment, which is currently being used by the South Dakota DOT for producing a video log, is provided in figure 4-3. The cameras can capture a 120-degree view of the road and its right-of-way. The equipment includes video or digital cameras, lasers, and GPS units for locating and recording asset information. The information is captured using on-board computers and processed after the surveys are completed. Asset conditions are reported using either automated or semi-automated methods. Some information, such as road roughness and rutting, can be obtained directly from lasers so condition information can be processed using automated techniques. However, most condition surveys must be conducted by viewing the digital images at a computer or workstation where deficiencies can be identified and reported. For this methodology to be successful, it is critical that all assets can be viewed by the equipment as it travels at near traffic speeds. A view from the guardrail video log program used by the Idaho DOT is provided in figure 4-4.

Figure 4-3. Mobile data collection technology used in South Dakota for video log (from SDDOT web site).

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Figure 4-4. View of video log image (FHWA 2005). Some of the advantages and disadvantages to manual and mobile data collection activities are detailed in the literature (AASHTO 2006). A summary of these advantages and disadvantages is presented in table 4-1. Table 4-1. Summary of advantages and disadvantages associated with manual and mobile data collection techniques (from AASHTO 2006). Method Manual

• • •

Mobile

• • • • •

Advantages Relatively accurate Detailed information can be collected Allows access to assets not readily visible from travel lanes Low initial costs Multiple assets can be assessed at the same time Data collected at travel speeds Multiple users can access the data Crews are not required to be out on the road

• • • • • • • • •

Disadvantages Process is slow Activities may be subject to seasonal conditions Training required to ensure consistency Labor intensive Safety of the raters May require a large, on-going investment Data collection limited to assets that are readily visible from the travel lanes Requires specialized crews Traffic congestion may interfere with data collection

Selecting a Data Collection Method The selection of the most appropriate method for collecting condition data is dependent on the particular asset being evaluated and the accessibility of the asset to survey crews. Where safety issues are a concern, mobile technology might be preferred over manual methods for certain

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assets (like pavements and guardrails). General guidelines for using manual and mobile technology for collecting condition information are presented in table 4-2. Table 4-2. Suitability of manual or mobile methods of data collection (from AASHTO 2006). Asset Categories Drainage

Roadside

Pavement

Asset Types Culvert Curb and gutter

Data Collection Method Manual Manual

Asset Categories Traffic Items

Asset Types Signal Sign

Sidewalk

Manual

Pavement markings

Ditch Drop inlet and storm drain Erosion control

Manual Manual

Pavement marker Overhead sign structure

Manual

Under or edge drain

Manual

Traffic barrier/median barriers Highway lighting

Fence Grass mowing

Manual or Mobile As Needed

Brush

As Needed

Landscaping Sound barrier Shoulder

Manual Manual Manual or Mobile Manual or Mobile Manual or Mobile

Lane, paved Lane, unpaved

Guardrail & Attenuators

Guardrail Guardrail end treatments Impact attenuator

Other Facilities

Tunnels Rest areas Weigh stations Roadside Graffiti Roadside Litter

Data Collection Method Manual Manual or Mobile Manual or Mobile Mobile Manual or Mobile Manual Manual or Mobile Manual or Mobile Manual or Mobile Manual or Mobile Manual Manual Manual Manual Manual or Mobile

A review of the findings from the survey conducted as part of the development of this Guide indicates that the majority of agencies still use manual surveys to collect maintenance condition information. However, an increasing number of agencies are using a combination of automated equipment and manual surveys as discussed in the next section. Interestingly, several agencies indicated that they are using voice recording devices during the surveys. Coordinated Data Collection Programs Since only a limited number of maintenance features can be viewed during surveys conducted using mobile technology, most agencies use mobile data collection techniques in conjunction with some other type of data collection activity performed for other purposes. Most commonly, agencies are collecting pavement condition information using mobile technology to support their pavement management activities. By adding several additional cameras, the equipment can be outfitted to record additional features such as guardrail, markings, and signs. Activities like these that combine data collection activities from disparate users can be very cost-effective and should be explored whenever possible.

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Idaho DOT has developed a state-of-the-art roadway video logging survey system to monitor the condition of its 5,400 guardrail sections (FHWA 2005). While collecting images of the guardrail, the vehicle also collects digital images and roadway curvature data used for traffic applications, and GPS latitude and longitude data for mapping and interfacing with their Geographic Information System (GIS). The Department is developing methods to capture images from the video log to work orders, capital planning documents, and other materials produced by the DOT. Because of the importance of nighttime visibility of signs and pavement markings to the safety of the traveling public, the retroreflectivity of these assets is often included as a performance measure. In order to collect this information, agencies might consider night surveys to collect condition information on signs, pavement markings, and lighting. Obtaining and Maintaining Quality in CAS As described in the next chapter, the results of the data collection activities described in this Guide are used to support a number of maintenance and operations activities. For that reason, it is critical that the quality of the data be as high as possible. Taking steps to ensure the objectivity and repeatability of the condition survey procedures is one step towards assuring the quality of the data. However, other important steps should also be built into the condition assessment process. Several suggestions for obtaining and maintaining data quality are provided. •

Develop manuals describing how each asset should be assessed.



Train the field inspectors and calibrate the crews annually. For consistency purposes, try to include at least one person in each crew who is a carryover from previous years. Some agencies use the same individuals to conduct the assessments each year.



Compare the ratings from one inspection to another to verify that the change in conditions is reasonable.



Assign inspectors responsibility for rating assets they are not responsible for maintaining.



Have the rating team supervisor randomly conduct quality control checks during each round of inspections so that any problems with the rating process can be addressed before the ratings are completed.



Develop a quality assurance (QA) process in which an independent rater verifies the ratings in a fixed percentage (such as 5 to 10 percent) or minimum number (25 is suggested in the literature) of the samples surveyed (Stivers et al. 1999). While annual checks of the data may be sufficient, more frequent attention may be required if certain teams are having problems producing accurate and consistent ratings (Stivers et al. 1999). QA inspections should verify that the appropriate assets have been rated and that the ratings are accurate.

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Tips for Success To help ensure the success of the condition assessment system, the following suggestions are offered by Operations personnel who have been involved in conducting condition assessment surveys for a number of years. •

Obtain upper level support for the process.



Keep the amount of data that needs to be collected in the field at a manageable level.



Develop a process in which the overall ratings make intuitive sense to the raters.



Provide the field crews with the resources and training needed to conduct the assessments on a regular schedule.



Ensure the quality of the data.



Correlate budget expenditures to the results of the condition assessment surveys.



Have both field office and central office personnel participate in the development of the condition assessment survey to obtain buy-in to the process.



Identify a project champion willing to work with individuals from throughout the agency to see the project through.



Model systems from other states and/or use experienced consultants to help develop the process.



Keep the system simple.



Develop a system that’s flexible enough to adapt to needed changes.

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CHAPTER 5: USING RESULTS The results of the condition assessment can be used in a number of different ways, from reporting the condition of transportation assets to influencing the allocation of maintenance and operations budgets. This chapter introduces the use of the condition assessment results for these purposes and provides examples from state highway agencies where these tools have been used successfully. Reporting Asset Conditions The most basic use of the results of the condition assessment is to report the condition of transportation assets. These conditions can be reported on an agency-wide basis, or by a smaller subset such as a district, region, or county. To simplify the reporting of these conditions, average conditions are calculated as described in the next section. Calculating Representative Conditions By Segment or Maintenance Element At the network level, information on the average condition of each segment or the average condition of each maintenance element can be determined from a statistical assessment of the information from each inspected sample. Steps for calculating the mean LOS for an individual segment or for a particular maintenance element are presented below (Stivers et al. 1999): Step 1: Calculate the Mean LOS To determine the mean LOS for a segment, use the following equation: LOSS = ∑ LOSSi n where: LOSS = mean LOS of the segment LOSSi = individual segment LOS values for n sample segments. n = number of sample segments. To calculate the mean LOS for a particular maintenance element, use the individual element LOS values for n sample segments in the previous equation. Step 2: Calculate the Sample Variance Subtract the mean LOS for the segment (or the maintenance element) from each of the individual LOS ratings. Square each of these values, sum the squares, and divide the sum by n-1. Step 3: Calculate the Standard Deviation Take the square root of the sample variance calculated in step 2.

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Step 4: Form LOS Confidence Interval To establish the 95 percent confidence interval for the segment LOS rating, multiply the standard deviation from step 3 by 1.96 (which is the z-statistic for a 95 percent confidence level) and divide by the square root of n (this is the plus-or-minus term, and is a measure of the precision). Add and subtract the plus-or-minus term (the square root of n) to the mean segment LOS calculated in step 1. Once this interval is established, an agency can say that with 95 percent confidence that the true segment LOS is within the interval established. Comparing the desired or targeted LOS to the confidence interval indicates whether any remedial action is required or whether resources can be shifted to other maintenance needs. Since a higher level of confidence is required for the element LOS analysis, a 99.5 percent confidence level is used. To establish the 99.5 percent confidence interval for the element LOS rating, multiply the standard deviation from step 3 by 2.08 (which is the z-statistic for a 99.5 percent confidence level) and divide by the square root of n (this is the plus-or-minus term, and is a measure of the precision). Add and subtract the plus-or-minus term (the square root of n) to the mean element LOS calculated in step 1. This should result in a larger confidence interval than for the segment LOS rating. Once this interval is established, an agency can say that with 99.5 percent confidence that the true element LOS is within the interval established. Comparing the desired or targeted LOS to the confidence interval indicates whether any remedial action is required or whether resources can be shifted to other maintenance needs. Calculating Overall District/Region Ratings or An Overall Agency Rating To determine an overall rating for a geographic area, the LOS ratings for each facility are weighted using factors such as the number of centerline miles. A weighted LOS can be determined by multiplying the LOS rating for each facility (such as functional classification) within a geographic area by the total mileage for that type of facility and then dividing by the total mileage. This is illustrated in table 5-1. Table 5-1. Example calculation of overall LOS (from Stivers et al. 1999). District

1 2

LOS

Interstate Mileage

Product

72 80

100 150

7,200 9000

Non-Interstate NHS LOS Mileage Product 65 70

500 32,500 600 42,000 All Districts, All Systems

Total Miles 600 750 1350

All Systems Sum of Overall Products LOS 39,700 66.2 51,000 68.0 90,700 67.2

Presenting Results Central Office The reports generated by the central office typically provide summary information that can be used to present LOS results for the individual maintenance units, districts or regions, or the entire state. In addition, the central office typically prepares summary reports by maintenance category, which may be further subdivided by highway system or district. A number of different Applied Pavement Technology, Inc.

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formats may be used to present this information, including bar charts and tables. These formats allow managers to quickly determine changes in condition over time and/or in areas where maintenance activities area required. An example of the type of summary report prepared by the central office is presented in figure 5-1.

Percentage of Roadside Miles with Acceptable Conditions 94

Percent

90 86

2004

82

2005

78 74 70 D1

D2

D3

D4

D5

D6

D7

SHA

District

Figure 5-1. Sample summary report. District or Regional Offices In addition to the summary reports used to analyze conditions, information can be generated by district, region, or field office to provide additional information that can be used to schedule maintenance activities. These reports may include the following: •

Individual elements for all facility types, district-wide.



Individual maintenance units, for all facility types and individual elements.



Individual maintenance units, individual facility types, and all elements.



Individual ratings for various elements.

The primary purpose of these reports is to determine whether maintenance resources are being allocated appropriately, or whether resources need to be redirected to meet performance targets. An example of this type of report is provided in figure 5-2

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Figure 5-2. Sample maintenance summary report by district and field office (McRary 2004).

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Report Card Many agencies have had success reporting conditions using a report card approach. In figure 53, which provides a report card for the NCDOT interstate system, an average condition can be plotted by element and/or facility corresponding to the overall level of service being provided. Some agencies elect to show the range of values reported in addition to the average condition.

Figure 5-3. Sample report card (NCDOT 2006).

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Dashboard A recent development in presenting the results of condition assessments is the dashboard, which quickly summarizes the agency’s success at meeting performance targets in a visual format (using colors, numbers, and a familiar graphic) that is fairly easy to interpret. An example of the dashboard from the Minnesota DOT’s web site is presented as figure 5-4. The dashboard gauges in figure 5-4 reflect the average number of hours to snow-free lanes for various functional classifications of roads. For each functional classification, different performance criteria have been established. For example, the expectation for the super commuter routes is between 1 and 3 hours for bare lanes. If it takes between 3 and 4 hours to clear these routes, the gauge would indicate the agency’s performance is “under expectations.” Similarly, if it takes more than 4 hours to clear these routes, the rating would indicate “significantly under expectation.” The graph also allows the agency to report whether they are “over expectation.” In this example, that would indicate less than 1 hour until lanes are clear. According to this graphic, all roads are being cleared in accordance with the agency’s expectations.

Figure 5-4. Sample dashboard (Minnesota DOT website).

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Using Performance Targets to Establish Budget Requirements Performance targets are used to establish program objectives by setting the specified level of service identified by the agency for a given maintenance activity. NCHRP Report 422 states that the level of quality used to establish a performance target may be represented in one of the following four ways (Stivers et al. 1999): •

A specific threshold value that triggers a maintenance activity.



A written description that states the authorized maintenance activity.



A defined frequency of a maintenance effort or number of inspections.



A policy of replacing missing items and repairing damaged items.

A performance target can be used to determine whether assets are being maintained at an acceptable condition level and to determine a goal for future conditions. Performance targets can also be used to estimate resource needs associated with improvements to network conditions and to provide feedback to the traveling public on maintenance activities of high interest to stakeholders. It is important to understand the link between targeted performance levels and budget requirements before setting a performance target so an agency knows whether it has the resources needed to achieve the targeted LOS. An example of the type of information that must be compiled to establish budget requirements associated with different LOS is illustrated in figure 5-5. Similar tables are compiled for each of the highway systems based on historical maintenance cost information. The figures in each column reflect the cost of maintaining the system at each LOS. For instance, the annual cost of maintaining the Interstates at a LOS A is $1 million higher than the cost of maintaining a LOS B. However, there is only a $250,000 cost difference between maintaining a LOS B and a LOS C. Once this type of cost information is compiled for each maintenance feature, the cost of achieving targeted performance levels can be estimated. Some agencies choose to plot the cost information graphically, as shown in figure 5-6. In general, there is little cost associated with changing the LOS provided for maintenance features with relatively flat slopes. The big differences in cost are associated with those features with steeper slopes. A graphic display of this information provides a means of quickly determining which maintenance features are most susceptible to budget changes. For example, the graph allows operations personnel to quickly realize the budget requirements to raise the performance of blocked basins and/or cross lines from a LOS B to a LOS A. If, for example, the targeted LOS is a B for blocked basins, then the budget requirement is $1,632,495. However, the annual cost of maintaining a LOS A is $4,081,237. This concept of using historical maintenance expenditures for estimating budget needs is reflected in figure 5-7, which uses solid lines to illustrate the cost of maintaining a LOS B and dashed lines to illustrate the cost of providing a LOS A. Agencies are cautioned that capturing true historical costs may be more difficult than initially thought since it is often difficult to capture the agency’s actual costs for performing maintenance. In reality, the historical costs used often exclude some of the agency costs for labor such as retirement costs, union expenses, and so on. Applied Pavement Technology, Inc.

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Figure 5-5. Maintenance costs required to achieve different LOS on the Interstate System (NCDOT 2006). 4500000

Annual Mainteannce Costs

4000000 3500000 3000000 2500000 2000000 1500000 1000000 500000 0 A

B

C

D

Cross Line Blocked

Cross Line Damaged

Curb and Gutter Blocked

Curb and Gutter Damaged

Basin Blocked

Basin Damaged

Figure 5-6. Graphical display of annual maintenance costs for drainage elements (from NCDOT 2006). Applied Pavement Technology, Inc.

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Annual Expenditures Budget requirement to provide LOS A $15 million Budget requirement to provide LOS B

$10 million

$5 million

A

B

C

D

F

LOS

Figure 5-7. Example of the link between LOS and budget requirements. Traditionally, an agency’s annual budgeting activities have been based on historical expenditures or budgets that are increased or decreased to match available funding. This approach assumes that the level of service being provided is adequate and that adjustments in the funding level will address the right priorities. In some agencies, these assumptions may be correct. However, the use of historical cost data to document the annual maintenance costs associated with different levels of service provides the information needed to respond to questions from the Executive Level or from elected officials when asked about the impact of changes in maintenance budgeting. Therefore, agencies can be more responsive to these inquiries and can better communicate the agency’s need for funding and/or ability to meet customer expectations. Using Condition Information in Programming Activities Establishing Uniform Maintenance Conditions Information from a condition assessment can be used to establish uniform maintenance conditions on a statewide basis by comparing the actual LOS to the targeted LOS. Segments that fall within an acceptable range from the targeted LOS are considered to be in acceptable condition, while segments that fall below the acceptable range are considered to be in need of maintenance. Maintenance resources can be shifted away from segments with conditions that exceed the targeted range for LOS. This information can be very useful for scheduling maintenance resources and for establishing maintenance priorities on an agency-wide basis.

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Tips for Success Reporting maintenance conditions and establishing resource needs requires sound, reliable information that can be used as the basis for making decisions. Some suggestions for effectively using the results of the condition assessment system for supporting the budgeting process are provided. •

Establish credibility by presenting reliable data and sound recommendations.



Recognize that the system must be flexible enough to adapt to changes in agency priorities and funding levels.



Use historical cost information to link LOS to budget requirements.



Communicate the results internally and externally so that decision makers understand the process being used and field personnel understand the importance of the data they are collecting.

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CHAPTER 6: IMPLEMENTATION Implementation Approaches The implementation of a new condition assessment system is a significant undertaking for a transportation agency. In most cases, it represents a shift in the way the organization is doing business, moving from an output-based management philosophy to an outcome-based philosophy that places an increased emphasis on customer priorities. Agencies that have successfully made this transition have taken one of two primary approaches to its implementation. One approach is to “bite the bullet” and undertake the full implementation statewide once the procedures have been developed. A second approach is first to implement the process on a portion of the system, and expand to the remainder of the system once the first phase has been successfully completed. Agencies that adopt this second approach might pilot the CAS on the NHS routes or in one district before initiating the statewide implementation. Both of these implementation approaches have advantages and disadvantages associated with them. These advantages and disadvantages are presented in the remainder of this section of the Guide. Full Implementation Under a full implementation, the transportation agency implements the new condition assessment procedures agency wide following the acceptance of the process. The implementation normally includes training on the new data collection and reporting procedures so that all stakeholders have a good understanding of why the changes were made, how they will be impacted by the changes, and what benefits the agency expects to make. Those individuals who will be responsible for collecting the data will receive more detailed training on the data collection procedures. The detailed training should include a field component so that the survey results from field personnel can be calibrated to help ensure agency-wide consistency. There are several primary advantages to the use of a full-scale implementation, as listed below: •

The data needed for making decisions is available sooner than if a pilot is used.



Everyone is trained at the same time.



The agency only has to go through the implementation process once.

There are also several disadvantages associated with this approach. Some of the primary disadvantages are listed. •

A large number of resources are required to support the full-scale implementation.



If there are adjustments needed to the program, the adjustments must be made agency wide.



It takes a significant effort to build the inventory for the entire system.

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Pilot Implementation Alternatively, the agency may elect to implement the new condition assessment system on a portion of the agency’s network before starting the agency-wide implementation. The pilot implementation could be approached in a number of different ways. Some agencies prefer to pilot the approach by system, starting on the highest-volume system first since this portion of the network typically receives more funding than the lower-volume roads. Other agencies prefer to pilot the methodology in a geographic area, such as a region or a district. In either case, the philosophy behind a pilot implementation is to test the process and make any adjustments that may be needed before moving to the full implementation. Some agencies recommend a pilot implementation as a way to build buy-in into the new system so there is more support when the full implementation begins. In retrospect, a number of agencies that went through a full implementation indicate that they might start with a pilot implementation if they were to do it over again, primarily because of the number of issues that typically arise during the full-scale implementation. These agencies indicate that they would have preferred to have been able to demonstrate some success before moving forward. Some of the advantages associated with the use of a pilot are listed below: •

A smaller number of resources are required.



The agency can build buy-in to the process gradually.



Any adjustments to the process can be made without impacting the entire data collection process.



The agency can demonstrate success before doing the full implementation.



The pilot implementation can focus on the system with the best possible data.

The following are some of the primary disadvantages associated with starting with a pilot implementation: •

The full implementation will take longer, since it is being conducted in two stages.



Building the inventory for a pilot area may require a significant effort.



The data needed for making budgeting decisions is not available as soon as it would be under a full-scale implementation.



Several training sessions will be required.

Keys to Success Agencies that have implemented a new condition assessment system offer the following tips for success: •

Provide the training needed to learn the new skills required to collect, report, and use the data.

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Obtain top-level support to help emphasize the importance of the changes and to help ensure that the new approach is used.



Build on the successes of others.



Start with the highest priority, most valuable or most important assets first.



Whether using the full implementation or pilot implementation, use caution; start slowly and allow the process to grow over time.



Link the effort to business functions to make it a success.



Communicate your successes.



Have a project champion to move the implementation forward.

Other keys to success that are outlined in the literature include the following (Stivers et al. 1999): •

Commit to quality from top management to each employee.



Build an agency commitment to continuous improvement.



Provide training and education opportunities for those responsible to help with the data collection activities.



Authorize employees to make more decisions and hold them accountable for the results of their decisions.



Foster an environment of open communication between employees and managers.

Barriers to Overcome The implementation of a change as substantial as the adoption of a new condition assessment system forces the agency to recognize that there are substantial technical and organizational issues that will need to be addressed. Some of the issues that may need to be addressed, as well as possible solutions for addressing each issue, are presented. Technical Issues •

Designing an appropriate system: Throughout this Guide, suggestions are made for developing a condition assessment system that matches the needs of an agency. There are many lessons that can be learned from the activities of other states that have developed new condition assessment procedures. In addition to the products from this research activity, there are a number of valuable resources available, including the results of recent Peer Workshops (such as the 2004 Peer Workshop conducted in Madison, WI). Some useful references are listed in Appendix B to this report. An agency may also benefit from the use of a consultant with experience in developing condition assessment systems.



Statistical reliability: Many agencies elect to use a sampling approach to collect maintenance condition information because they do not have the resources available to collect information on the entire network. When sampling is used, agencies should pay

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special attention to the statistical considerations that have to be taken into account. Again, excellent references are listed in Appendix B and statisticians can help address these aspects of the system development. •

Technology changes: Technological advancements are moving forward at a tremendous pace. These changes are impacting the way maintenance condition information is being collected. As much as possible, agencies should stay abreast of the changes that are taking place and incorporate new technology whenever possible.

Organizational Issues •

Resistance to change: Individuals are inherently resistant to change; therefore, it is especially important that the individuals who will be impacted most by the change in procedures understand the reason for the change and the benefit the changes bring to the organization. Training and stakeholder involvement in the development of the new condition assessment system are the keys to overcoming this issue.



Flavor of the month: Undoubtedly, transportation agencies have had to withstand a variety of temporary initiatives that have been initiated at the whim of senior officials with little thought or direction. For a condition assessment system to be successful, it must be integrated into the decision process within the organization and fully supported by upper management. Without this level of support, the data collection activities are meaningless and requests for the information will eventually be ignored.



Staffing: The collection of maintenance condition assessment data requires a substantial commitment of resources in terms of both personnel and time. As the condition assessment system is being designed, the agency should consider the resources available to support the system and design the system to match the available resources. If additional resources will be needed, a commitment for those resources should be secured before moving forward with the full scale implementation or the amount of data being collected will have to be adjusted to fit the level of resources available.



Data quality: The results of the condition assessment are used as the basis for making decisions about allocating available maintenance and operations resources. Therefore, it is critical that the data be as reliable as possible. Annual training of the individuals responsible for data collection provides an opportunity for calibrating the crews for consistency and conveying the importance of the data. The availability of data collection manuals also play an important role in ensuring data quality.

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CHAPTER 7: SUMMARY One of the primary objectives of transportation agencies is to provide a safe, smooth, and efficient road network to the traveling public. As competition for transportation funds has increased in recent years, agencies have shifted their emphasis towards system preservation. As a result, the importance of maintenance effectiveness has increased, as has the need to link maintenance priorities to organizational performance objectives. In recent years, the use of maintenance CAS has emerged as a key factor in enabling agencies to set maintenance performance targets and to translate those targets into an effective maintenance program. Today’s operational environment is forcing many transportation agencies to make changes to their existing maintenance management practices so they can take advantage of enhanced technological capabilities, but more importantly so they can better respond to customer expectations and political demands. For some agencies, this has meant developing enhanced capabilities within their existing maintenance management program. However, a number of other agencies have initiated new processes and procedures that are more customer-oriented, outcome-focused, and integrated with other existing systems. This Guide focuses on the development of CAS that provides the information needed to effectively manage the maintenance and operations of today’s transportation agencies. There are a number of benefits associated with the use of an outcome-based condition assessment system. These benefits include more consistent conditions on a statewide basis, which result from a better understanding of maintenance conditions by maintenance personnel and the use of performance targets to set statewide maintenance priorities. Perhaps one of the greatest benefits to the use of a CAS is its role in helping maintenance and operations personnel establish maintenance priorities. The outcome-based performance measures that are used in today’s CAS are more customer-oriented than the output-based performance measures used in the past. For example, performance is measured in terms of the number of hours until a road has been cleared after a winter storm rather than the amount of salt used or the number of hours worked. As a result of these changes, maintenance personnel are able to establish work programs that place a priority on the issues that are of most concern to the traveling public. By linking the CAS to budgeting and resource planning tools, transportation agencies are also better equipped to respond to customer inquiries about raising the level of service being provided in one or more areas. With the establishment of these links, agencies can better report the consequences associated with shifting resources from one area to another. This Guide can be used by transportation agencies interested in developing a new condition assessment system or modifying an existing system to better serve as a budgeting and resource planning tool. It outlines considerations that should be taken into account in developing a CAS and demonstrates the use of the results to report network conditions and estimate resource and budgeting requirements. Additional information on the state of the practice in this area among state highway practitioners is available in the accompanying Final Report for this project.

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References

REFERENCES American Association of State Highway and Transportation Officials (AASHTO). 2005. Guidelines for Maintenance Management Systems. AASHTO, Washington, DC. American Association of State Highway and Transportation Officials (AASHTO). 2006. Asset Management Data Collection Guide. TF 45-1. AASHTO, Washington, DC. Cameron, J., J. Crossett, and C. Secrest. 2003. Strategic Performance Measures for State Departments of Transportation: A Handbook for CEOs and Executives. NCHRP Project 2024(20) Final Report. Transportation Research Board, Washington, DC. Federal Highway Administration (FHWA). 1999. Asset Management Primer. FHWA. Washington, DC. Federal Highway Administration (FHWA). 2005. Transportation Asset management System for Roadway Safety. Report No. FHWA-HRT-05-055. FHWA, Washington, DC. Hyman, W. 2004. Guide for Customer-Driven Benchmarking of Maintenance Activities. NCHRP Report 511. Transportation Research Board, Washington, DC. McRary, K. 2004. Level of Maintenance Summary. Florida Department of Transportation. http://www.mrutc.org/outreach/MQAlibrary/Florida. Monroe, E., J. Bittner, A. Lebwohl. 2004. Proceedings Document: Maintenance Quality Assurance Peer Exchange. Report No. MRUTC-MQAI-MN85. Midwest Regional University Transportation Center, Madison, WI. North Carolina Department of Transportation (NCDOT). 1998. Maintenance Condition Survey Manual. North Carolina Department of Transportation, Raleigh, NC. North Carolina Department of Transportation (NCDOT). 2000. Maintenance Condition and Funding Needs. North Carolina Department of Transportation, Raleigh, NC. North Carolina DOT (NCDOT). 2006. Maintenance Condition and Funding Needs for the North Carolina Highway System. North Carolina DOT, Raleigh, NC. Schmitt, R. L., S. Owusu-Ababio, R. M. Weed, and E. V. Nordheim. 2006. Development of a Guide to Statistics in Maintenance Quality Assurance Programs in Transportation. Midwest Regional University Transportation Center, Madison, WI. Stivers, M.L., K.L. Smith, T. E. Hoerner, and A.R. Romine. 1999. Maintenance QA Program Implementation Manual. NCHRP Report 422. Transportation Research Board, Washington, DC.

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References

Utah DOT. 2006. Maintenance Management Quality Assurance Plus Inspection Manual. Utah Department of Transportation, Salt Lake City, Utah. Washington State Department of Transportation (WSDOT). 2004. Maintenance Accountability Process Manual. Washington State Department of Transportation, Olympia, WA. Zimmerman, K.A. and A. S. Wolters. 2005. Principles and Practices for Enhanced Maintenance Management Systems. Instructor’s Guide, FHWA-NHI-05-146. Federal Highway Administration, Washington, DC. Zimmerman, K.A. and M. Stivers. 2007. A Model Guide for Condition Assessment Systems: Final Report. National Cooperative Highway Research Program, Washington, DC.

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Appendices

Appendix A Glossary of Terms

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GLOSSARY OF TERMS As part of this project, a survey was distributed to Operations personnel in each of the state highway agencies within the United States. To help ensure consistency in the responses to the survey, definitions were provided to the participants. These definitions, plus others deemed important to the content of this Guide, are provided in this appendix to assist the reader. Asset An asset is a physical item of roadway infrastructure that has value. Assets are sometimes referred to as roadway “furniture” or “features.” An asset may be a single item, such as a sign, or a linear item such as a road or guardrail section. An asset may also be a spatial item such as a rest area or mowable acreage. Asset Inventory An asset inventory is a physical count of assets. The count may be by coordinates, milepoints, road section, geographical area, road network, maintenance section, or other convenient method of sorting and reporting the amount of assets in the road system. Condition Assessment Condition assessment is a physical inspection and rating of roadway assets to determine the condition of individual assets, roadway sections, or overall road networks. Level of Service (LOS) Maintenance levels of service measure the condition of individual assets as well as the overall condition of the roadway. LOS measures are generally specified in customer service terms related to safety, preservation, convenience, aesthetics, comfort, and mobility. Some states also measure LOS in terms of environmental impacts or legislative mandates. Maintenance Management (MM) The actions associated with organizing, administering, and supervising highway maintenance activities, customer services, and infrastructure preservation. Maintenance Management System (MMS) Maintenance Management System (MMS) A modern MMS integrates organization structure, business processes, and technology to provide a systematic approach for planning and executing an efficient customer-oriented and performance-based maintenance program. Maintenance Quality Assessment (MQA) Maintenance quality assessment is a process of physically inspecting and rating the condition of the roadway assets and maintenance services. The quality assessment employs the same measures used to set performance targets. The data from the maintenance quality assessment is used to assess outcomes, actual performance, and maintenance LOS.

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A Guide to Maintenance Condition Assessment Systems

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Outcomes Outcomes are similar to levels of service and specify the overall results achieved from the maintenance program. Performance Measure A performance measure is a unit of measurement used to rate asset condition or maintenance performance. Examples of performance measures include height of grass, number of potholes per lane mile, and percent of signs below standard. Performance Target A performance target is a goal or objective for the condition of assets on the road system. A performance target is usually a numerical rating, such as the desired percentage of highway features that meet a Performance Measure (i.e., at least 90 percent of all roadway lighting shall be operational.) Threshold Condition The condition above which an asset must be maintained in order to meet the expectations of the agency. Assets that fall below the threshold condition require corrective action.

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A Guide to Maintenance Condition Assessment Systems

Appendices

Appendix B Useful References

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A Guide to Maintenance Condition Assessment Systems

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There are a number of references that may be helpful as you develop a new condition assessment system. The recommended references are grouped by subject in alphabetical order. References applicable to several topics are listed under each of the appropriate headings. Maintenance Quality Assurance Programs Monroe, E., J. Bittner, A. Lebwohl. 2004. Proceedings Document: Maintenance Quality Assurance Peer Exchange. Report No. MRUTC-MQAI-MN85. Midwest Regional University Transportation Center, Madison, WI. Stivers, M.L., K.L. Smith, T. E. Hoerner, and A.R. Romine. 1999. Maintenance QA Program Implementation Manual. NCHRP Report 422. Transportation Research Board, Washington, DC. Statistics Schmitt, R. L., S. Owusu-Ababio, R. M. Weed, and E. V. Nordheim. 2006. Development of a Guide to Statistics in Maintenance Quality Assurance Programs in Transportation. Midwest Regional University Transportation Center, Madison, WI. Maintenance Management Systems American Association of State Highway and Transportation Officials (AASHTO). 2005. Guidelines for Maintenance Management Systems. AASHTO, Washington, DC. Data Collection Procedures American Association of State Highway and Transportation Officials (AASHTO). 2006. Asset Management Data Collection Guide. TF 45-1. AASHTO, Washington, DC. Asset Management Federal Highway Administration (FHWA). 1999. Asset Management Primer. FHWA. Washington, DC.

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