NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL REPORT March 2010 PREPARED FOR
City of Nampa, Public Works Department
PREPARED BY
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
TABLE OF CONTENTS EXECUTIVE SUMMARY .................................................................................1 INTRODUCTION..............................................................................................9 TRAVEL DEMAND MODELING ..................................................................11 Demographic Assumptions .......................................................................................................... 11 Network Assumptions..................................................................................................................... 12 Turning Movement Forecasts ..................................................................................................... 13
NEEDS ANALYSIS METHODOLOGY ........................................................14 Arterial Roadway Analysis ........................................................................................................... 14 Arterial Roadway Thresholds ........................................................................................................ 14 Arterial Roadway Capacity Analysis........................................................................................... 16 Recommended Roadway Design Criteria ................................................................................. 19 Intersection Analysis Methodology ........................................................................................ 23 Recommended Intersection Thresholds ................................................................................... 23 Geometric Standards....................................................................................................................... 27 Intersection Capacity Analysis ..................................................................................................... 28
COMMUNITY-BASED NEEDS.....................................................................40 NEXT STEPS ...................................................................................................46 REFERENCES: ................................................................................................47 APPENDIX A: NEEDS ASSESSMENT.......................................................49
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
TABLE OF FIGURES Figure 1: Study Area ....................................................................................................... 10 Figure 2: Planning-Level Intersections; 3-Lane Arterial .................................................. 31 Figure 3: Planning-Level Intersections; 5-Lane Arterial .................................................. 32 Figure 4: Planning-Level Intersections; 7-Lane Arterial (A and B) .................................. 33 Figure 5: Planning-Level Intersections; 7-Lane Arterial (C and D).................................. 34
TABLE OF TABLES Table 1: Urbanized Area Directional Peak Hour Volume Level of Service Thresholds... 15 Table 2: Nampa Citywide Transportation Plan Daily Arterial LOS D Thresholds............ 15 Table 3: 2010 Needed Roadway Improvements............................................................. 16 Table 4: 2015 Needed Roadway Improvements............................................................. 16 Table 5: 2020 Needed Roadway Improvements............................................................. 17 Table 6: 2025 Needed Roadway Improvements............................................................. 17 Table 7: 2030 Needed Roadway Improvements............................................................. 18 Table 8: 2035 Needed Roadway Improvements............................................................. 18 Table 9: Nampa Roadway Design Policy Minimum Widths ............................................ 20 Table 10: Recommended Nampa Street Cross-Section Design Policy .......................... 22 Table 11: Generalized Intersection LOS D Planning Thresholds.................................... 25 Table 12: Generalized Roundabout Intersection LOS D Planning Thresholds ............... 25 Table 13: Right Turn Edge of Traveled Way Recommended Standards ........................ 27 Table 14: Specific Intersection Configuration Needs ...................................................... 30 Table 15: 2010 Intersection Improvement Needs ........................................................... 36 Table 16: 2015 Intersection Improvement Needs ........................................................... 37 Table 17: 2020 Intersection Improvement Needs ........................................................... 38 Table 18: 2025 Intersection Improvement Needs ........................................................... 39 Table 19: 2030 Intersection Improvement Needs ........................................................... 40 Table 20: 2035 Intersection Improvement Needs ........................................................... 40 Table 21: Community Identified Needs ........................................................................... 41
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
ACRONYMS AASHTO AWSC ADT CHD4 CIM COMPASS GIS HCM 2000 HCS I-84 ITD ITE LOS MPO NHD1 PCI STIP SH-45 TIP TMA TWSC UPRR US-20/26 v/c VRT
American Association of State Highway and Transportation Officials All-Way Stop Control Average Daily Traffic Canyon Highway District # 4 Communities in Motion – the current Long Range Transportation Plan for Ada and Canyon Counties Community Planning Association of Southwest Idaho Geographic Information System Highway Capacity Manual, Year 2000 edition Highway Capacity Software Interstate 84 Idaho Transportation Department Institute of Transportation Engineers Level of Service Metropolitan Planning Organization Nampa Highway District # 1 Pavement Condition Index Statewide Transportation Improvement Program State Highway 45 Transportation Improvement Program Transportation Management Area Two-Way Stop Control Union Pacific Railroad United States Highway 20/26 Volume to capacity ratio Valley Regional Transit
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Executive Summary Nampa’s high connectivity to regional highways, railroad, public transportation, and proximity to the Boise Air Terminal provide a robust transportation system. Traffic levels have increased as a result of this connectivity and Nampa’s large growth rate. The increased traffic has led to congestion, increased travel times, and other associated problems. A blueprint for improving and expanding the transportation roadway systems throughout the city of Nampa and the surrounding area is needed. URS Washington Division (URS) is developing the Nampa Citywide Transportation Plan, including a capital improvement plan (CIP), to aid in the planning of future transportation investments. The following planning level assessment of the arterial roadways and intersections within the study area was conducted to determine improvements needed to obtain the desired level of service now (2010), in 2035, and for several interim years (2015, 2020, 20205, and 2030). This analysis serves as the basis for the Needs provided in the project lists. The Community Planning Association of Southwest Idaho (COMPASS) maintains a regional travel demand model that forecasts traffic volumes for both average weekday and the PM peak hour conditions in the study area. For the purposes of forecasting travel demand in the study area and assessing the transportation needs, the COMPASS regional travel demand model was used. Demographic forecasts recently completed by the Nampa Public Works Department to provide long-range population and land use data for planning city infrastructure were input into the COMPASS model. For the arterial roadway needs assessment, traffic volume thresholds were established to determine when roadway segments and intersections require improvements. These performance standards are based on those used both locally and by other jurisdictions in the country. After some discussion regarding the merits of using thresholds based on LOS E as opposed to LOS D, LOS D was chosen as the most appropriate for the plan for a number of reasons: • It is the de facto standard in the Treasure Valley as many regional planning studies base their needs assessments on LOS D, including Communities in Motion • It allows some flexibility in recommending improvements as it does not represent complete failure of roadway segments • It provides more comprehensive projects list For each arterial roadway in the Nampa planning area, traffic volume forecasts were compared to the LOS D threshold for the current roadway lane configuration (number of 1
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
lanes). When a segment volume exceeded the threshold, the number of lanes (lane configuration) needed was estimated based on a 2035 demand. Two levels of capacity analyses were conducted for intersections. For all arterial corridor intersections within the Nampa planning area other than those specifically identified by the Nampa Public Works Department, a planning-level analysis was conducted. Specific intersections identified by the City of Nampa Public Works staff were analyzed using the HCS+ software to determine intersection configurations needed to meet 2035 demands. The planning-level analysis does not provide the detail necessary to identify future intersection configurations, but it does identify the need for increased capacity (i.e. adding turn lanes). For the intersection needs assessment, two types of planning thresholds were developed: • For current stop controlled intersections that are forecasted to require future signalization, a v/c ratio of 0.90 was used for the overall intersection with lane groups within that intersection having a v/c of 1.00 or less. Needed intersection configurations will be based on meeting both conditions. • All other intersections were analyzed and needs based on the overall intersection LOS D thresholds. In order to develop the thresholds, generalized assumptions were made about the TWSC, AWSC, and signalized intersections in the study area: o The major street of a 4-leg TWSC intersection includes one through lane plus turn pockets. The minor street has one through lane and no turn pockets. o AWSC intersections have single lane approaches o Signalized intersections have left turn lanes on all legs Roundabout implementation was also analyzed. Without conducting a specific capacity analysis with specific intersection data, it is difficult to estimate whether a roundabout will function at an adequate LOS. In addition, roundabouts may not be appropriate for every arterial intersection. Therefore, screening criteria were developed to determine if a roundabout would be appropriate for the given arterial intersection. The screening criteria are based on guidelines from the FHWA Roundabouts: An Informational Guide and the ACHD Ada County Roundabout Study: Draft Roundabout Application Guidelines for Ada County. The needs analysis resulted in the identification of approximately 122 miles of roadway improvements and 120 intersection improvements. Tables ES1 through ES6 summarizes the identified needs for 2010 through 2035, respectively. 2
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table ES1: Capacity Based 2010 Improvement Needs Facility
Location
Roadway
Intersection
Needed Improvement
Karcher Rd. (SH-55) Karcher Rd. (SH-55) US 20/26
Midway Rd. to Sundance Rd. Sundance Rd. to I-84 Madison Rd. to Can Ada Rd.
Widen to 5 lanes Widen to 6 lanes Widen to 5 lanes
2nd St. South 2nd St. South 3rd St. South (I-84 Bus.) 3rd St. South (I-84 Bus.) 7th St. South 7th St. South Amity Rd.* Caldwell Blvd. (I-84 Bus.) Caldwell Blvd. (I-84 Bus.) Cherry Ln.1 Cherry Ln.1 Cherry Ln.2 Davis Ave. Garrity Blvd. (I-84 Bus.) Garrity Blvd. (I-84 Bus.) Garrity Blvd. (I-84 Bus.) Garrity Blvd. (I-84 Bus.) Greenhurst Rd.1, 4 Greenhurst Rd.4 High St. Homedale Rd. Karcher Ave. (SH-55) Karcher Ave. (SH-55) Karcher Ave. (SH-55) Karcher Ave. (SH-55) Lake Lowell Ave.4 Lone Star Rd.4 Marketplace Blvd. Orchard Ave. Orchard Ave.2, 4 Roosevelt Ave.1, 4 Smith Ave. US 20/26
11th Ave. South (I-84 Bus.) Northside Blvd. 12th Ave. South (SH-45) Northside Blvd. 11th Ave. South 12th Ave. South (SH-45) Robinson Rd. Middleton Rd. Midland Blvd. Can-Ada Rd. Franklin Blvd. Northside Blvd. Yale St. 11th Ave. North 16th Ave. North Kings Rd. Stamm Lane Happy Valley Rd. Robinson Rd. Yale St. Caldwell Blvd. (I-84 Bus.) Caldwell Blvd. (I-84 Bus.) Cassia St. Middleton Rd. Midway Rd. Midland Blvd. Midland Blvd. Midland Blvd. Caldwell Blvd. (I-84 Bus.) Middleton Rd. Midland Blvd. Midland Blvd. Can-Ada Rd. 11th Ave. North Can-Ada Rd. Franklin Blvd. Madison Rd. Star Rd. Kings Rd. Happy Valley Rd.
Add turn lanes Add lanes Add turn lanes Add lanes Add lanes Add turn lanes Dual lane roundabout Add turn lanes Add turn lanes Add signal and turn lanes Add signal and turn lanes Add signal and turn lanes Add signal Add turn lanes Add turn lanes Add turn lanes Add turn lanes Dual lane roundabout Dual lane roundabout Add signal Add turn lanes Add turn lanes Add turn lanes Add turn lanes Add signal Single lane roundabout Single lane roundabout Add lanes Add turn lanes Single lane roundabout Add signal Add turn lanes Add signal and turn lanes Add signal and turn lanes Add signal and turn lanes Add signal and turn lanes Add signal Add signal and turn lanes Dual lane roundabout Dual lane roundabout
Ustick Rd.1 Ustick Rd.1 Ustick Rd.1 Ustick Rd.1 Ustick Rd.1
Victory Rd.2 Victory Rd.4 Indicates ITD jurisdiction
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO 1
3 4
Shared jurisdiction with local Highway District 2 Local Highway District
Intersection met all screening criteria for a dual lane roundabout
Existing signal warrant analysis completed, shows need for improvements with current volumes ** Intersection met all screening criteria for a dual lane roundabout
Table ES1:2015 Capacity Based 2015 Improvement Needs Facility
Location
Roadway
Intersection
Needed Improvement
12th Ave. South (SH-45) Caldwell Blvd. (I-84 Bus.) Cherry Ln.1 Franklin Rd. Franklin Blvd.1
Sunrise Rim Rd. to Dooley Ln. Homedale Rd. to Canyon St. Midland Blvd. to McDermott Rd. Gate Blvd. to McDermott Rd. Karcher Rd. to Linden St.
Widen to 5 lanes Widen to 6 lanes Widen to 5 lanes Widen to 5 lanes Widen to 5 lanes
Happy Valley Rd.1 Midland Blvd.1
Greenhurst Rd. to Amity Rd. Marketplace Blvd. to Ustick Rd.
Widen to 5 lanes Widen to 5 lanes
2nd St. South Birch Ln. Cherry Ln.1 Cherry Ln.2,4 Franklin Rd.1,4 Garrity Blvd. (I-84 Bus.) Greenhurst Rd.1 Greenhurst Rd.1 Iowa Ave. Karcher Rd. US 20/26 US 20/26 US 20/26 US 20/26
12th Ave. South (SH-45) Franklin Blvd. Midland Blvd. Star Rd. Star Rd. 39th Ave. North Midland Blvd. Southside Blvd. Midland Blvd. Franklin Blvd. 11th Ave. North Franklin Blvd. Madison Rd. Northside Blvd. McDermott Rd.
Ustick Rd.
1
Add turn lanes Add signal & turn lanes Add lanes Dual lane roundabout Dual lane roundabout Add signal & turn lanes Single lane roundabout Add turn lanes Add signal Dual lane roundabout Add signal & turn lanes Add signal & turn lanes Add signal & turn lanes Add signal & turn lanes Add signal & turn lanes
Indicates ITD jurisdiction 1
3 4
Shared jurisdiction with local Highway District 2 Local Highway District
Intersection met all screening criteria for a dual lane roundabout
Existing signal warrant analysis completed, shows need for improvements with current volumes
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
TableES3: Capacity Based 2020 Improvement Needs Facility
Location Amity Rd. Amity Rd.1 Garrity Blvd. (I-84 Bus.)
Roadway
Intersection
Greenhurst Rd.1 Kuna Rd.2 Lone Star Rd. Ustick Rd.2 Victory Rd1 11th Ave. South (I-84 Bus.) 2nd St. South 3rd St. South 3rd Street South (I-84 Bus.) Birch Ln. Cherry Ln.1 Hawaii Ave. Karcher Connector Locust Ln. Locust Ln.2 Ustick Rd.1 Ustick Rd.
1, †
Chestnut St. to Southside Blvd. Grays Ln. to McDermott Rd. Franklin Blvd. to I-84 Southside Blvd. to Happy Valley Rd. Track Rd. to McDermott Rd. Canyon St. to Greenleaf St. Midland Blvd. to McDermott Rd. Sugar St. to McDermott Rd. 3rd St. South to Garrity Blvd. 16th Ave. South 7th Ave. South 11th Ave. South (I-84 Bus.) 11th Ave. North 11th Ave. North Holly St. Midland Blvd. 12th Ave. South (SH-45) Robinson Rd. Midland Blvd. Northside Blvd.
Needed Improvement Widen to 5 lanes Widen to 5 lanes Widen to 6 lanes Widen to 5 lanes Widen to 5 lanes Widen to 5 lanes Widen to 5 lanes Widen to 5 lanes Widen to 6 lanes Add turn lanes Add signal Add lanes Add signal Dual lane roundabout Add signal Add turn lanes Add signal Single lane roundabout Add signal & turn lanes Add signal & turn lanes
Indicates ITD jurisdiction 1
Shared jurisdiction with local Highway District 2 Local Highway District †Year of need based on roadway improvement
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
TableES4: Capacity Based 2025 Improvement Needs Facility
Roadway
Intersection
Location
Needed Improvement
3rd St. North Greenhurst Rd. Greenhurst Rd. Locust Ln.1 11th Ave. North1 12th Ave. South (SH-45) 16th Ave. South Can-Ada Rd.1 McDermott Rd.2 Northside Blvd.1 Star Rd.1
16th Ave. North to Sugar St. Middleton Rd. to Horton St. Happy Valley Rd. to McDermott Rd. Midland Blvd. to McDermott Rd. I-84 to Ustick Rd. Bowmont Rd. to Lake Shore Dr. Roosevelt Ave. to Garrity Blvd. Birch Ln. to US 20/26 I-84 to Ustick Rd. Karcher Rd. to Ustick Rd. I-84 to Ustick Rd.
2nd St. South 3rd St. North 3rd St. South 7th St. South Airport Rd.2 Airport Rd.2 Amity Rd.1 Amity Rd.1 Amity Rd. Cherry Ln.1 Flamingo Ave. Franklin Rd.1 Greenhurst Rd.2 Iowa Ave. Kuna Rd.2
7th Ave. South 16th Ave. South 16th Ave. South 7th Ave. South Happy Valley Rd. Robinson Rd. Happy Valley Rd. McDermott Rd. Powerline Rd. McDermott Rd. Middleton Rd.1 McDermott Rd. Robinson Rd. Middleton Rd. Southside Blvd.
Add signal & turn lanes Add turn lanes Add turn lanes Add signal Add signal & turn lanes Single lane roundabout Dual lane roundabout Dual lane roundabout Dual lane roundabout Add signal Single lane roundabout Add signal & turn lanes Dual lane roundabout Single lane roundabout Single lane roundabout
Locust Ln.1 Locust Ln.1 Lone Star Rd.
McDermott Rd. Southside Blvd. Canyon St. East†
Add signal Add signal Add turn lanes
Lone Star Rd.
Canyon St. West†
Orchard Ave. Victory Rd.2 Victory Rd.1 Indicates ITD jurisdiction
1
Lake Ave. Robinson Rd. McDermott Rd.
Widen to 5 lanes Widen to 3 lanes Widen to 3 lanes Widen to 5 lanes Widen to 5 lanes Widen to 3 lanes Widen to 5 lanes Widen to 5 lanes Widen to 3 lanes Widen to 3 lanes Widen to 5 lanes
Add turn lanes Single lane roundabout Dual lane roundabout Dual lane roundabout
1
Shared jurisdiction with local Highway District 2 Local Highway District † Closely spaced “T” intersections along Lone Star Road
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
TableES5: Capacity Based 2030 Improvement Needs Facility
Roadway
Location 7th St. South Airport Rd. Lone Star Rd. Orchard Ave.1 7th Ave. South Franklin Blvd. Happy Valley Rd.1 Idaho Center Blvd. Lake Ave.2 McDermott Rd.1 Middleton Rd.1 Midland Blvd.1
Yale St. to 16th Ave. South Kings Rd. to McDermott Rd. Middleton Rd. to Canyon St. Lake Ave. to Caldwell Blvd. Greenleaf St. to 1st St. South I-84 to Karcher Rd. Amity Rd. to Stamm Ln. I-84 to Birch Ln. Lake Lowell Ave. to Orchard Ave. Locust Ln. to Amity Rd. Greenhurst Rd. to Lake Lowell Ave. Locust Ln. to Lake Lowell Ave.
Widen to 5 lanes Widen to 3 lanes Widen to 3 lanes Widen to 3 lanes Widen to 3 lanes Widen to 6 lanes Widen to 3 lanes Widen to 6 lanes Widen to 3 lanes Widen to 3 lanes Widen to 3 lanes Widen to 3 lanes
Robinson Rd.2 Robinson Rd.2
Lewis Ln. to Amity Rd. Victory Rd. to I-84
Widen to 3 lanes Widen to 3 lanes
Colorado Ave.
Holly St.
1
Intersection
Needed Improvement
Greenhurst Rd. Greenhurst Rd.1 Lone Star Rd.1 Smith Ave.
Sunnyridge Rd./Holly St. S. Powerline Rd. Middleton Rd. Middleton Rd.
Add signal3 Add turn lanes Add turn lanes Single lane roundabout Single lane roundabout
Indicates ITD jurisdiction 1
3
Shared jurisdiction with local Highway District 2 Local Highway District
Intersection met all screening criteria for a dual lane roundabout
TableES6: Capacity Based 2035 Improvement Needs Facility
Roadway
Intersection
Location Ustick Rd.2 11th Ave. North Middleton Rd.1 Southside Blvd.1
Midland Blvd. to McDermott Rd. Garrity Blvd. to I-84 Lake Lowell Ave. to I-84 Bowmont Rd. to Greenhurst Rd.
Bowmont/Kuna-Mora Rd.2 Iowa Ave. Lake Lowell Ave. Lake Lowell Ave.1
Southside Blvd. 12th Ave. South (SH-45) 12th Ave. South (SH-45) Middleton Rd. Lake Ave.
Lone Star Rd. Indicates ITD jurisdiction
2
1
Needed Improvement Widen to 6 lanes Widen to 3 lanes Widen to 3 lanes Widen to 3 lanes Single Lane Roundabout Add Turn Lanes Add Turn Lanes Single Lane Roundabout Single Lane Roundabout
Shared jurisdiction with local Highway District 2 Local Highway District
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
In additional to the capacity-based needs, 81 community-based needs were identified. Community-based needs are transportation improvements that were identified by members of the Community Advisory Committee and other stakeholders. They were identified by the public using two processes, a utility bill and a Web-based survey. Many of the needs identified were related to bicycle, pedestrian and public transportation modes. These identified needs will be prioritized based on available funding. To do this, ranking criteria will be developed and estimated project costs documented. Prioritized projects and their estimated costs will be applied to the estimates of available funding to develop a capital improvement plan for the City of Nampa. This will be a critical element of the overall Citywide Transportation Plan.
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Introduction Nampa’s high connectivity to regional highways, railroad, public transportation, and proximity to the Boise Air Terminal provide a complete transportation system. Traffic levels have increased as a result of this connectivity and Nampa’s large growth rate attributed to robust development. The increased traffic has led to congestion, increased travel times, and associated problems. A blueprint for improving and expanding the transportation roadway systems throughout the city of Nampa and the surrounding area is needed. URS Washington Division (URS) is developing the Nampa Citywide Transportation Plan, including a capital improvement plan (CIP), for use by the City of Nampa to plan future transportation investments. To support this effort, the following planning level needs assessment of the arterial roadways and intersections within the proposed study area was conducted to determine improvements needed for adequate operations now (2010), in the future (2035), and for the interim years (2015, 2020, 20205, and 2030). This needs assessment analysis serves as the basis for the improvements presented in project lists. The study area for this planning effort encompasses the current Nampa city limits and its proposed area of impact. Figure 1 presents the Nampa Citywide Transportation Plan study area boundaries. Roughly, the geography is: • North to US 20/26 • East to McDermott Rd. • South to Bowmont Rd. • West to Midway Road/Rim Rd. To aid in the discussion of the City of Nampa’s transportation system existing conditions and needed improvements, the study area has been divided into five regions: North, South, East, West, and Central/Downtown. Figure 1 also shows the boundaries of these regions. The Existing Transportation System Technical Memo finalized in May 2009 provides an inventory of the conditions of the existing transportation system within the study area.
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N
NAMPA CITYWIDE TRANSPORTATION PLAN STUDY AREA Nampa Citywide Transportation Plan
0
55
1/2
1
2
SCALE IN MILES
JOPLIN RD
I-84 26 ADA COUNTY
LIN DER RD
M ERIDIAN RD
FAI RVI EW LANE
TEN M ILE RD
BLACK CAT RD
CHERRY LANE
VD BL
I-184 FRANKLIN RD
I-84
LAKE LOWELL AVE AMITY AVE
I-84
ADA COUNTY
CANYON COUNTY
CAN YO N ST
M C DERM O TT RD
USTI CK RD
STAR RD
IDAH O CEN TER BLVD
CANYON COUNTY M IDLAN D RD
M IDDLETO N RD
M IDW AY RD
IN DIAN A AVE
ROOSEVELT AVE
26
MC MI LLAN RD
S ST
LONE STAR RD
TY I RR GA
D 2N
LAK E AVE
55
W. KARCHER RD
11TH AVE N EXT
HOMEDALE RD
FRAN K LIN BLVD
B L V D
N O RTH SIDE RD
E L L
M IDLAN D RD
C A L D W
USTI CK RD
20 M IDDLETO N RD
20
VI CTORY RD
AMITY AVE
IOWA AVE GREENHURST RD LAKE HAZEL RD
R D
M C DERM O TT RD
RO BIN SO N BLVD
H APPY VALLEY RD
SO U TH SIDE BLVD
SO U TH PO W ERLIN E RD
12 TH AVE S.RD
LYN W O O D RD
DEARBO RN E RD
MISSOURI AVE
RIM RD
DEER FLAT RD
SK Y RAN CH RD
LEWIS LN
COLUMBIA RD
HUBBARD RD
DEER FLAT RD
KUNA RD
M ERIDIAN RD
LOCUST LN
69
LIN DER RD
45
TEN M ILE RD
G R EE N H U R ST
BLACK CAT RD
LAKE LOWELL
LEGEND Study Area Boundary
North Region Study Area BENNETT RD
West Region Study Area
BOWMONT RD
Downtown Region Study Area
East Region Study Area
South Region Study Area
FIGURE 1 I
D
A
H
O
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Travel Demand Modeling Travel demand models are built to replicate (or are calibrated to) the traffic conditions of a specific year. To do so, a model’s output is compared to traffic counts taken during the same year the model was built to replicate. Acceptable performance is determined via a statistical analysis of the entire modeling domain, referred to as model validation. Once a model is calibrated and validated, it is considered ready to forecast traffic volumes. The Community Planning Association of Southwest Idaho (COMPASS) maintains a regional travel demand model that forecasts traffic volumes for both average weekday and PM peak hour conditions in the study area. The current COMPASS model is calibrated and validated for the year 2002. Specific details regarding the COMPASS model calibration/validation process can be found in the 2002 Travel Demand Forecast Model Calibration Report for Ada and Canyon Counties. Current and future roadway and intersection needs are based on forecasts produced by the COMPASS model. Specific assumptions were made regarding growth (demographic forecasts) and future roadway connections (model network) to develop the travel demand forecasts for the Nampa Citywide Transportation Plan. In an effort to update the calibration of the COMPASS model, existing traffic counts (2008 conditions) were compared against 2008 model forecasts. In most cases the traffic volume forecasts were considered within acceptable performance standards, based on those currently used by COMPASS to calibrate and validate the regional model. However, there were a few locations with unacceptable discrepancies between the traffic counts and model forecast. Minor adjustments to the model network were made consisting of the addition of Birch Lane and adjustments to several centroid connections.
Demographic Assumptions URS held meetings with COMPASS and City of Nampa staff to discuss the demographic assumptions and travel demand modeling efforts for the needs assessment. The official 2030 demographic forecast used to develop COMPASS Communities in Motion (CIM) long range regional transportation plan is known as the “Community Choices” 2030 growth scenario. “Community Choices” combines modest land use intensification/densification along transportation corridors with additional employment and population growth in outlying communities. Less suburban residential development is anticipated in this growth scenario. With more infill development (and thus increased densities) along existing transportation corridors, this scenario consumes less land by 2030 than the current development trend. 11
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Nampa recently completed a demographic forecast specific to the study area; Demographic Forecast and Land Use Analysis for the Nampa Study Area and South Study Areas 2007-2030. This document provided long-range population and land use data for the purpose of planning city infrastructure. Data from this document were used as the basis for forecasting roadway and intersection needs within the study area while outside the study area, the official “Community Choices” scenario was used. Commercial growth (in the form of jobs) and residential growth are incorporated into COMPASS’ travel demand model through the use of specific geographic areas called traffic analysis zones (TAZs). When a regional travel demand model is used to forecast traffic volumes for a specific area, the established TAZ structure may be too coarse to effectively represent localized traffic patterns. It can be necessary to divide large TAZs found in the regional structure into smaller geographies, redistributing the demographic data assigned to the original (parent) TAZ. For the COMPASS model to effectively use the Nampa specific demographic data, the size of the TAZs in the study area were reviewed. TAZ splits within the study area were recommended by the City of Nampa and implemented by COMPASS. Adjustments to the Nampa specific demographic data were necessary to implement the TAZ splits. Specifically for 2008, housing data adjustments were made through comparisons to COMPASS estimates which are based on 2000 Census data and building permit data from Canyon County and the City of Nampa. Because the Nampa demographic forecasts base commercial and industrial development on acreages and not number and type of jobs, COMPASS used 2008 Idaho Department of Labor (DOL) data and apportioned it to TAZs. To forecast housing and employment in the study area, growth estimates per TAZ provided in the Demographic Forecast and Land Use Analysis for the Nampa Study Area and South Study Areas 2007-2030 were applied to the 2008 data. Forecasts for the year 2035 were made by applying the annual growth rate estimated between 2025 and 2030 to the 2030 estimates for a five year period.
Network Assumptions Four primary roadway networks were developed and modeled for the purposes of forecasting travel demand and assessing the transportation needs in the study area: •
Current year (2008): This model network represents the regional arterial and interstate system as it currently exists. It was used to validate the COMPASS model with revised TAZs and 2008 demographics as previously described.
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
•
•
•
Base year (2010): This model network represents the regional arterial and interstate system as it exists today and includes projects identified in the FY20092013 Northern Ada County Transportation Improvement Program (COMPASS report # 13-2008) that will be constructed and open to the public by December of 2010. It was used in combination with 2010 demographic forecasts and represents the “base year” for the needs analysis. 2010 was selected at the base year for the analysis to coincide with the base year of COMPASS’ next transportation improvement program. Year 2015: It represents the regional arterial and interstate system that is provided by the 2010 network, the FY2009-2013 Northern Ada County Transportation Improvement Program (COMPASS report # 13-2008), and non-programmed projects likely to be complete by 2015 as determined through consultation with the City of Nampa, City of Caldwell, the Idaho Transportation Department (ITD), the Ada County Highway District (ACHD), the Nampa Highway District # 1 (NHD1), and the Canyon Highway District # 4 (CHD4). Two non-programmed roadway improvements were added. They include a small amount of widening on Karcher Road (State Highway 55) and the 2-lane connection of Bowmont Road to Swan Falls Road. The 2015 network was used to forecast travel demand for the years 2015, 2020, 2025, and 2030 by using the appropriate demographic forecasts. Horizon year (2035): The 2035 model network was created using the 2015 network and adding roadway projects likely to be complete by 2035 as determined through consultation with the City of Nampa, City of Caldwell, the Ada County Highway District, Nampa Highway District, and Canyon Highway District. Several roadway improvements were added to the 2015 network. They include: o A 5-lane Ustick Road from Eagle Road in Meridian to I-84 in Caldwell o A new 2-lane connection of Airport Road in Nampa to Overland Road in Meridian o A new 2-lane western arterial through Canyon County that connects Bowmont Road from State Highway 45 to State Highway 55 using an alignment that connects with Malt Lane. The 2035 network was used to forecast travel demand using 2035 demographic forecasts.
Turning Movement Forecasts To assess the needs of specific intersections in the study area identified by the City of Nampa for more detailed analysis, PM peak hour turning movements were forecast using current turning volumes, COMPASS model forecasts, and “WinTurns.” WinTurns is a 13
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
software tool that forecasts turning volumes using the techniques described in NCHRP 255 (Highway Traffic Data for Urbanized Area Project Planning and Design, Chapter 8). It forecasts turning movements using an iterative approach which alternately balances the inflows and outflows of a given intersection until the results converge. Turning movement forecasts as produced by WinTurns are included in Appendix A (Needs Assessment). These forecasts were input into the Highway Capacity Software (HCS+) to identify the intersection configurations needed to meet the planning threshold at the specific intersections.
Needs Analysis Methodology Arterial Roadway Analysis The objectives of the arterial roadway needs analysis include: • Determining the needed roadway configurations based on 2035 forecast travel demand • Determining when the existing roadway configurations fall below the recommended planning thresholds Arterial Roadway Thresholds Traffic volume thresholds are recommended to determine when roadway segments and intersections require improvements. URS researched national and local performance standards to recommend the most appropriate to use in the needs analysis for the Nampa Citywide Transportation Plan. A comparison of planning level threshold volumes from a few sources is presented in Table 1. The selected threshold volumes from various sources are very similar for the same roadway designations. The appropriate Level of Service (LOS) threshold for this plan was determined. After some discussion regarding the merits of using thresholds based on LOS E as opposed to LOS D, LOS D was chosen as the most appropriate for the plan for a number of reasons: • It is the de facto standard in the Treasure Valley as many regional planning studies base their needs assessments on LOS D, including Communities in Motion • It allows some flexibility in recommending improvements as it does not represent complete failure of roadway segments • It provides more comprehensive projects list
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 1: Urbanized Area Directional Peak Hour Volume Level of Service Thresholds Arterial LOS D Thresholds
# of lanes
COMPASS Calibration Report Table 28
FDOT Generalized Table 4-7
ACHD CIP Table C-4
No Left Turn Lane Continuous Center Left-Turn Lane
1 1 2 3 1
700 830 1,660 2,250 830
608 760 1,620 2,450 798
550 750 1,600 2,440 790
Median Control
2
1,660
1,701
1,680
3
2,250
2,573
2,560
Arterial LOS E Thresholds
# of lanes
No Left Turn Lane Continuous Center Left-Turn Lane
1 1 2 3 1
780 925 1,840 2,490 925
648 810 1,720 2,580 851
690 880 1,770 2,660 920
Median Control
2
1,840
1,806
1,860
3
2,490
2,709
2,790
Daily thresholds were converted to directional peak hour volume thresholds to allow cross comparison. It is assumed the peak hour represents 10% of the daily volume. The ACHD Capital Improvements Plan (CIP) arterial thresholds are based on the Florida Department of Transportation (FDOT) generalized planning threshold tables, which are the most extensively researched in the nation. Therefore thresholds similar to those used by ACHD are recommended and were used for the needs analysis. Table 2 summarizes the daily planning level thresholds specific to this analysis. Because daily traffic forecasts are considered more reliable than peak hour forecasts, daily thresholds were developed for the arterial roadway needs analysis. Table 2: Nampa Citywide Transportation Plan Daily Arterial LOS D Thresholds Arterial Roadway Configuration No left-turn lane
Continuous Center Turn Lane
Median Controlled
# of Lanes per Direction
ADT LOS D Thresholds
1 2 1 2 3 1 2 3
5,500 11,000 7,500 16,000 24,400 7,900 16,800 25,600
15
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Arterial Roadway Capacity Analysis For each region of the Nampa planning area, traffic volume forecasts were compared to the thresholds specified in Table 2. Comparisons were made using forecasts for arterial roadway segments given the analysis years of 2010 [Base Year], 2015, 2020, 2025, 2030, and 2035. When a segment volume exceeded the established threshold, the number of lanes (lane configuration) needed to meet 2035 demand was estimated and recommended for implementation in the given analysis year. Based on the analysis, several roadway improvements are needed to accommodate the forecasted travel demand by the horizon year (2035). Tables 3 through 8 display the identified roadway needs for each analysis year. Improvements identified for state facilities are shaded. Roadway needs specific to each region within the study area are provided in Appendix A (Needs Assessment). Note that the jurisdiction associated with each corridor is based on a map of the highway districts in Canyon County as provided by the Canyon Highway District #4 website (September 2009). Table 3: 2010 Needed Roadway Improvements Jurisdiction
ITD
Corridor Karcher Rd. (SH-55) Karcher Rd. (SH-55)
Location
Current # of Lanes
Needed # of Lanes
Midway Rd. to Sundance Rd.
2
5
2
6
2
5
Sundance Rd. to I-84 Madison Rd. to Can Ada Rd.
US 20/26
Table 4: 2015 Needed Roadway Improvements Jurisdiction
Corridor
ITD
12th Ave. South (SH-45) Caldwell Blvd. (I-84 Bus.) Cherry Ln.1 Franklin Rd.
Nampa
1
Franklin Blvd.
Happy Valley Rd. Midland Blvd. 1
1
Current # of Lanes
Needed # of Lanes
2
5
5
6
Midland Blvd. to McDermott Rd.
2
5
Gate Blvd. to McDermott Rd.
2
5
Location
1
Sunrise Rim Rd. to Dooley Ln. Homedale Rd. to Canyon St.
Karcher Rd. to Linden St.
2
5
Greenhurst Rd. to Amity Rd.
2
5
Marketplace Blvd. to Ustick Rd.
2
5
Shared jurisdiction with local Highway District
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 5: 2020 Needed Roadway Improvements Current # of Lanes
Needed # of Lanes
5
6
5
6
Chestnut St. to Southside Blvd.
2
5
2
5
Greenhurst Rd.1
Grays Ln. to McDermott Rd. Southside Blvd. to Happy Valley Rd.
2
5
Kuna Rd.2
Track Rd. to McDermott Rd.
2
5
Jurisdiction
Corridor
Location
ITD
Garrity Blvd. (I-84 Bus.) 11th Ave. South (I-84 Bus.) Amity Rd. Amity Rd.
Nampa
1
Lone Star Rd. Ustick Rd.
2
Victory Rd1 1
Franklin Blvd. to I-84 3rd St. South to Garrity Blvd.
Canyon St. to Greenleaf St.
2
5
Midland Blvd. to McDermott Rd.
2
5
Sugar St. to McDermott Rd.
2
5
Shared jurisdiction with local Highway District 2 Local Highway District
Table 6: 2025 Needed Roadway Improvements Jurisdiction ITD
Corridor
Location
Needed # of Lanes
2
3
12th Ave. South (SH-45)
Bowmont Rd. to Lake Shore Dr.
3rd St. North
16th Ave. North to Sugar St.
2
5
Greenhurst Rd.
Middleton Rd. to Horton St. Happy Valley Rd. to McDermott Rd.
2
3
2
3
Midland Blvd. to McDermott Rd.
2
5
I-84 to Ustick Rd.
2
5
Roosevelt Ave. to Garrity Blvd.
4
5
Birch Ln. to US 20/26
2
5
I-84 to Ustick Rd.
2
3
Karcher Rd. to Ustick Rd.
2
3
I-84 to Ustick Rd.
2
5
Greenhurst Rd. Locust Ln.1 Nampa
Current # of Lanes
th
11
1
Ave. North
16th Ave. South Can-Ada Rd.
1 2
McDermott Rd.
Northside Blvd. 1
Star Rd.
1
1
Shared jurisdiction with local Highway District 2 Local Highway District
17
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 7: 2030 Needed Roadway Improvements Jurisdiction
7th St. South
Yale St. to 16th Ave. South
Current # of Lanes 3
Airport Rd.
Kings Rd. to McDermott Rd.
2
3
Middleton Rd. to Canyon St.
2
3
Lake Ave. to Caldwell Blvd.
2
3
Greenleaf St. to 1st St. South
2
3
Franklin Blvd.
I-84 to Karcher Rd.
5
6
Happy Valley Rd.1
Amity Rd. to Stamm Ln.
2
3
Idaho Center Blvd.
I-84 to Birch Ln.
5
6
Lake Lowell Ave. to Orchard Ave.
2
3
Corridor
Location
Lone Star Rd. Orchard Ave.
1
7th Ave. South
Nampa
Lake Ave.
2 1
Locust Ln. to Amity Rd.
2
3
1
Greenhurst Rd. to Lake Lowell Ave.
2
3
1
Locust Ln. to Lake Lowell Ave.
2
3
2
Lewis Ln. to Amity Rd.
2
3
2
Victory Rd. to I-84
2
3
McDermott Rd. Middleton Rd. Midland Blvd.
Needed # of Lanes 5
Robinson Rd.
Robinson Rd.
1
Shared jurisdiction with local Highway District 2 Local Highway District
Table 8: 2035 Needed Roadway Improvements Jurisdiction
Corridor
Location
Ustick Rd.2 Nampa
Midland Blvd. to McDermott Rd.
11th Ave. North Middleton Rd.
1
Southside Blvd. 1
3
1
Existing # of Lanes3 5
Needed # of Lanes 6
Garrity Blvd. to I-84
2
3
Lake Lowell Ave. to I-84
2
3
Bowmont Rd. to Greenhurst Rd.
2
3
Shared jurisdiction with local Highway District 2 Local Highway District
Analysis assumes Ustick Rd. is widened to 5 lanes by 2035
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Recommended Roadway Design Criteria URS reviewed the City of Nampa’s current roadway design policy based on the recommendations found in the 2004 AASHTO Policy on Geometric Design of Highway and Streets (also known as the AASHTO “Green Book”) and the 1999 AASHTO Guide for the Development of Bicycle Facilities. Nampa’s current standards are found in the 2005 City of Nampa Design Policy included in the Subdivision Process and Policy Manual. Table 9 is a re-creation of Exhibit “B” from the Subdivision Process and Policy Manual and presents the current minimum widths allowed for collector and arterial street classifications in Nampa. Arterial Roadways without Bicycle Lanes The current Nampa arterial lane, sidewalk, and planter width standards meet the desirable AASHTO design recommendations for arterials without bike lanes. Arterial roadway lane widths should be between 10 to 12 feet. 10 foot lanes are not recommended except for highly restricted areas with little or no truck traffic. 11 foot lanes may be used when right-of-way or other constraints exist and the speed limit is 45 mph or less. 12 foot lane widths are desirable and should be used on higher speed principal arterials. Curbs should be offset 1 to 2 feet from the edge of traveled way. When no parking is allowed, the outside lane should be 13 to 14 feet wide to provide this separation. When the sidewalks are separated from the curb by a planter strip, they should be at least 5 feet wide. When they are adjacent to the curb, they should be 2 feet wider for a total of 7. Collectors and Local Roadways without Bicycle Lanes The current Nampa collector lane, parking lane, sidewalk, and planter width standards meet the desirable AASHTO design recommendations for arterials without bike lanes. Collector and local roadway lane widths should be between 10 to 12 feet. Parking lanes, when allowed, should be between 7 to 8 feet in residential areas and 8 to 11 feet in commercial and industrial areas. 8 feet is desirable as a vehicle will occupy 7 feet of actual space. Additional width will allow better clearance for vehicles and people entering and exiting the vehicles. Two-way left turn lanes should be between 10 to 16 feet. Curbs should be offset 1 to 2 feet from the edge of traveled way. When the sidewalks are separated from the curb by a planter strip, they should be at least 5 feet wide. When they are adjacent to the curb, they should be 2 feet wider or 7 feet wide.
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 9: Nampa Roadway Design Policy Minimum Widths (Exhibit “B” from the Subdivision Process and Policy Manual) * Landscape Buffer Min Street Layout Collector Collector w/ Shared Shoulder Arterial w/ Shared Shoulder and Adjacent Sidewalk Arterial w/ Shared Shoulder and Detached Sidewalk
To Property Line
Side Walk
Planter
Curb & Gutter
Parking/ Shoulder
Outer Lane
Inside Lane
Center Lane
Right of Way
Pavement
Back of Curb
Residential
Other
25
15
6
5
7
2
8
0
12
0
80
40
44
25
15
6
5
7
2
0
0
14
12
40
40
44
25
15
8
7
0
2
0
14
12
14
100
66
70
25
15
3
5
7
2
0
14
12
14
100
66
70
All dimensions in feet*
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Bicycle Facilities along Arterials and Collectors Bicycles can travel along collectors and arterials either in designated bike lanes, in a shared outside travel lane, or on paved shoulders. If there is no curb and gutter adjacent to the roadway, paved shoulders should be at least 4 feet wide to accommodate bicycles. If there is curb, guardrail or barrier along the roadway, the shoulder width should be 5 feet. If the bicycle shares the travel lane with vehicles, a 14 foot wide outside lane is recommended as measured from the lane stripe to the longitudinal joint of the gutter pan. The Nampa standards provide for this shared lane on both the collectors and arterials. If a separate bike lane is designated for a roadway, it should be 5 feet wide as measured from the edge of traveled way to the face of curb. The designation between the bike lane and the edge of traveled way should be delineated by a 6 inch white painted line. This width can include a 1 to 2 foot wide gutter pan as long as a minimum 3 foot wide paved surface is provided between the gutter pan and the travel lane. If on-street parking is allowed along a roadway, the 5 foot wide bike lane should be between the travel lane and the parking area. Recommendations Recommended roadway design elements are presented in Table 10. Several arterial segments are recommended for six travel lanes to accommodate future travel demand. Therefore, a seven lane arterial section is included to provide guidance on the development of these future large arterials. Also, it is recommended that the language of section 80.05 of the City of Nampa Design Policy be updated to allow some flexibility in street widths. This will allow alternate lane widths and configurations to meet specific scenarios as roadways throughout the city are improved. It will also provide the Public Works Department with flexibility when approving reasonable alternates needed to meet documented design challenges. An example of the language recommended is: Street Widths: Streets shall be designed with the following standard widths listed on Exhibit “B”. These widths are standards and alternative widths or configurations may be submitted to the City Engineer for consideration
21
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 10: Recommended Nampa Street Cross-Section Design Policy All dimensions in feet Lane
Lane
Bicycle Lane 1
Parking
Planter
Sidewalk
4
Rightofway 60
Pavement
6
To Prop. Line 1
34
Back of Curb 38
4
6
2
8
9
9
8
Curb & Gutter 2
5
5
8
2
8
12
12
8
2
8
5
5
80
40
44
C-3-N
Collector - w/ on-street Parking Collector - New facilities
3
5
8
2
4
12
12
12
4
2
8
5
3
80
44
48
C-3-R
Collector - Existing; Retrofit 2
5
5
8
2
4
10.5
11
10.5
4
2
8
5
5
80
40
44
Minor Arterial - 3 Lane w/ onstreet Parking and Bike Lane
2
5
8
2
4
14
14
14
4
2
8
5
2
100
66
70
A-3-P
2
5
8
2
11
11
14
11
11
2
8
5
2
100
66
70
A-5 A-7
Minor Arterial - 5 Lane w/ Bike Lane 2 Major Arterial - 5 Lane Major Arterial - 7 Lane
2 2.5
5 5
8 8
2 2
14 12
12 12
14 14
12 12
14 12
2 2
8 8
5 5
2 2.5
100 125
66 90
70 94
I-2-P
Industrial - 2 Lane w/ Parking
2
5
12
12
12
5
2
70
52
56
A-5-B
Lane
Parking
8
Center Lane
Curb & Gutter
C-2-P
Lane
Planter
Local - SD N-820A
Lane
Sidewalk
L-2
Lane
To Prop. Line 1
Street Type
Bicycle Lane 1
8
3
2
4
14 8
4
14 8
2
Key:
Notes: SD - Standard Drawing from City of Nampa Construction Guide
1
Bike Lane is the width of ride-able surface. Total Bike Lane width includes the gutter pan (1.5 feet) Posted speeds should not exceed 35 MPH, reflecting lane widths that are less than 12 foot. 3 Parking is allowed next to the curb, sharing the 14-foot travel lane 2
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Intersection Analysis Methodology The objectives of this intersection capacity analysis include: • Determining the needed intersection configurations to operate adequately with 2035 forecast travel demand • Determining when the existing intersection configurations fall below the recommended thresholds between now and 2035 • Conduct capacity analyses to identify conceptual configurations and control types at specific locations Prior to implementation, additional capacity analysis and signal warrant analyses should be completed by the Nampa Public Works Department using location specific traffic information.
Recommended Intersection Thresholds As with roadways, planning-level thresholds were established for arterial roadway intersections in the planning area. Based on the information collected on existing conditions, all arterial intersections in the study area are either all way stop controlled (AWSC), two way stop controlled (TWSC), signal controlled, or controlled with a roundabout. Planning thresholds only developed for identifying whether existing intersection control will be sufficient for future demand or if there is a need to improve intersection control with traffic signal or roundabout treatments. Signalized Intersection Thresholds URS researched available planning thresholds for signalized intersections. As with the planning thresholds for roadways, intersection thresholds were obtained for LOS D. The thresholds used by ACHD and documented in Table C-5 of their CIP for signalized intersection use a volume to capacity ratio (v/c) of 0.90 to represent LOS D. The v/c ratio is calculated using peak hour conditions, a saturation flow rate of 1,900 vehicles per lane per hour, and a peak hour factor of 0.90. For signalized intersections, ACHD bases their planning-level analyses on a cycle length of 150 seconds, a minimum of 20 seconds for left turns, and 3 seconds of “lost time.” Using an analysis method similar to ACHD’s would require a specific capacity analysis of every arterial intersection in the study area. Because the Nampa Citywide Transportation Plan will only conduct capacity analyses for specific intersections identified by Public Works staff, other analysis methods were explored for all other arterial intersections in the study area. Chapter 10 of the 2000 edition of the Highway Capacity Manual (HCM 2000) contains several examples of peak 23
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
hour approach volumes that equate to LOS ratings A through E. Specifically, Exhibits 10-24, 10-28, 10-29, and 10-30 provide service volume ranges for signalized intersections, TWSC “T” intersections, 4-leg TWSC intersections, and AWSC intersections respectively. Tables of the thresholds used in this Plan were developed using the HCM 2000 exhibits and are provided in Appendix A. All assumptions used to develop the tables can be found in Chapter 10 of HCM 2000. Based on the information collected, two types of planning thresholds were developed for intersections within the study area. Note that these values are to be used for planning purposes and do not represent a detailed capacity analysis of the intersections: • For current stop controlled intersections that are forecasted to require future signalization, a v/c ratio of 0.90 was used for the overall intersection with lane groups within that intersection having a v/c of 1.00 or less. Needed intersection configurations will be based on meeting both conditions. Using the v/c ratio results based on forecast traffic volumes, planning level intersection layouts, and defined parameters will give an indication of signalized operations with potential improvements. • All other intersections were analyzed and recommendations made based on the overall intersection LOS D thresholds provided in Table 11. In order to develop the generalized thresholds in Table 9, a typical TWSC, AWSC, and signalized intersection was assumed for the study area. The typical intersections were assumed to have the following configurations: o The major street of a 4-leg TWSC intersection includes one through lane, one left turn pocket, and one right turn pocket. The minor street has one through lane and no turn pockets. o AWSC intersections have single lane approaches with no turn pockets o Signalized intersections have one left turn lane on all legs and a shared through/right turn lane Table 12 presents the planning level thresholds used to analyze roundabouts.
24
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 11: Generalized Intersection LOS D Planning Thresholds Intersection Type
Through Lanes per Approach
TWSC "T"
1
TWSC
1
AWSC Signalized
1 2 1 2 3
Major Street Maximum Service Volumes (veh/hr) 200 400 600 800 1,000 500 1,000 1,500 340 480 530 1090 1510
Minor Street Maximum Service Volumes (veh/hr) 700 530 390 270 180 260 70 N/A N/A N/A N/A N/A N/A
Table 12: Generalized Roundabout Intersection LOS D Planning Thresholds Total Volume on all
Approach Volume to
Approaches (veh/hr)
Capacity Ratio
Single Lane
2,090
0.90
Dual Lane
4,180
0.90
Roundabout Intersection
Roundabout Intersection Thresholds Without conducting a specific capacity analysis with specific intersection data, it is difficult to estimate whether a roundabout will function at an adequate LOS. In addition, roundabouts may not be appropriate for every arterial intersection. Therefore, screening criteria were developed to determine if a roundabout would be appropriate for the given arterial intersection. The screening criteria are based on guidelines from the FHWA Roundabouts: An Informational Guide and the ACHD Ada County Roundabout Study: Draft Roundabout Application Guidelines for Ada County and include: 1. A stop-controlled intersection that fails with forecast volumes 2. Low expected pedestrian volumes at the intersection 3. Moderate terrain around the intersection 4. Proximity of adjacent roundabouts on the corridor 5. Feasible right-of-way available for roundabout 6. Forecast volumes are appropriate for roundabouts 7. Roundabout is appropriate for functional classification of the roadway 25
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
All criteria must be met for a roundabout to be considered at a specific location. Additionally, it was assumed that a signalized intersection would not be replaced with a roundabout. Therefore, existing signalized intersections were not considered. Note that there are many other factors that should be considered before a decision is made to design and build a roundabout. The intent of these criteria is to identify intersections that are good candidates for roundabout treatments which may warrant further study/consideration. Once roundabout locations were screened, the same v/c ratio threshold used for signalized intersections (0.90, based on LOS D) was applied as the roundabout planning threshold. Planning-level v/c ratios for roundabouts were estimated using two methods. The method applied for general intersections not singled out for specific capacity analyses involves using a correlation developed by the Institute of Transportation Engineers (ITE). Table 7-17 in the Transportation Planning Handbook (2nd edition) identifies roundabout approach volumes and estimates of v/c ratios. To achieve a v/c of 0.90 equating to LOS D, the total peak hour volume on all approaches should not exceed 2,090 vehicles per hour for a single-lane roundabout. It was assumed for planning purposes that dual lane roundabouts will be able to serve twice the approach volumes listed in Table 7-17 for single lane roundabouts. A planning chart found in chapter 3 of the FHWA Roundabouts: An Informational Guide presents similar information on single and dual lane roundabout capacities and supports the assumption that dual lane roundabouts can serve approximately twice the approach volumes of single lane roundabouts. All roundabout recommendations are based on the needs of the roadway approach configurations. If the roadway segments beyond the intersection approaches require 2 travel lanes in each direction to operate adequately in the design year, a dual lane roundabout was needed. Intersections of major roadways requiring more than 2 travel lanes in each direction were not considered for roundabout treatments. A more robust analysis was conducted for the specific intersections identified by the Nampa Public Works staff to determine if roundabouts would be a reasonable alternative to signals. The identified non-signalized intersections were analyzed to calculate roundabout capacity using forecasted traffic volumes and FHWA’s capacity method found in Roundabouts: An Informational Guide. This method provides information in a manner similar to the HCS output for a signalized intersection. The v/c ratio calculated in the analysis for these intersections was compared to the v/c ratio threshold of 0.90 to determine if roundabouts were feasible.
26
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Geometric Standards There are several intersections included in the Nampa Citywide Transportation Plan that have geometric deficiencies, specifically related to heavy vehicle movements. These include intersections that are skewed or have tight right turn radii. The City of Nampa does not identify a design vehicle for intersections but does require minimum curb radii for intersection improvements as part of their platting process. Specific design vehicles should be selected during conceptual and preliminary design of specific projects. For the purposes of the Nampa Citywide Transportation Plan, it is recommended that a Large School Bus (S-BUS-40) be used as the design vehicle for developing the planning level intersection configurations and to analyze geometric issues at existing arterial intersections with collectors or local roads. It is recommended that an Interstate Semi-trailer (WB-67) be used as the design vehicle to analyze geometric issues at existing arterial intersections where trucks may be present. These include intersections along I-84 Business Loop (e.g. the 2nd and 3rd couplet, Garrity Blvd.) and other principal and minor arterials. The appropriate turning standards from the AASHTO Green Book are recommended in Table 13 to accommodate these design vehicles. Specific alternative designs should be investigated and evaluated in the concept and design stages of intersection improvement projects. Table 13: Right Turn Edge of Traveled Way Recommended Standards Angle of Turn Design Vehicle
75
90
105
Simple Curve Radius with Taper
Simple Curve Radius with Taper
Simple Curve Radius with Taper
Radius (ft)
Offset (ft)
Taper L:T
Radius (ft)
Offset (ft)
Taper L:T
Radius (ft)
Offset (ft)
Taper L:T
Large School Bus (S-BUS-40)
60
2
15:1
45
5
10:1
40
4
10:1
Interstate Semi-Trailer (WB-67)
145
4.5
15:1
125
4.5
6:1
115
3
15:1
Source: 2004-AASHTO A Policy on Geometric Design of Highways and Streets (Green Book) Exhibit 9-19
27
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Intersection Capacity Analysis Specific Intersection Configurations Several specific intersections have been identified by the City of Nampa Public Works staff to be analyzed using Highway Capacity Software (HCS+). They include: • • • • • • • • • • • • • •
Cherry Lane & Can Ada Road Cherry Lane & Franklin Boulevard Cherry Lane & Northside Boulevard Colorado Avenue & Holly Street Yale Street & Davis Avenue Flamingo Avenue & Happy Valley Road Garrity Boulevard & 11th Avenue North Garrity Boulevard & 16th Avenue North Garrity Boulevard & 39th Avenue North Garrity Boulevard & Kings Road Greenhurst Road & S. Powerline Road Greenhurst Road & Sunny Ridge Road Greenhurst Road & Southside Boulevard Hawaii Avenue & Holly Street
• • • • • • • • • • • • • • •
Yale Street & High Street Lone Star Road & Fairview Avenue Roosevelt Street & 10th Avenue Roosevelt Street & Canyon Road Roosevelt Street & Holly Street Stamm Road & Happy Valley Road Ustick Road & Can Ada Road Ustick Road and Franklin Road Ustick Road & 11th Avenue North Ustick Road & Madison Road Ustick Road & Star Road 16th Avenue & 3rd Street North Caldwell Boulevard & Midland Boulevard SH 45 & Locust Lane Victory Road & Happy Valley Road
Current peak hour turning movement counts for each intersection were provided by the City of Nampa and a capacity analysis using HCS+ performed for two conditions: the Existing (2008) peak hour conditions and 2035 forecasted peak hour conditions. In conjunction with the 2035 COMPASS peak hour model forecast, WinTurns was used to forecast 2035 turning movements for each intersection. The capacity analysis consisted of determining the current LOS for each intersection, determining the LOS in 2035 given the existing configuration (no build or do nothing), and then determining the intersection improvements required to meet the planning threshold in 2035. All intersections were considered for roundabout implementation based on the screening criteria and capacity analysis methodology discussed.
28
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 14 summarizes the intersection improvements required to meet the planning thresholds and the year in which the current intersection configuration will likely become deficient. Figures 2 through 5 depict the planning-level intersection configurations based on the roadway needs of each leg. The number and type of legs in these figures are referenced for each intersection in Table 14. Prior to implementation of these recommendations, conceptual design and warrant analyses should be completed by the Nampa Public Works Department using location specific traffic information
29
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 14: Specific Intersection Configuration Needs Intersection
3rd St. North &16th Ave. Caldwell Blvd. & Midland Rd. Cherry Ln. & Can Ada Rd. Cherry Ln. & Franklin Blvd. Cherry Ln. & Northside Blvd. Colorado Ave. & Holly St.
Davis Ave. & Yale St. Garrity Blvd. & 11th Ave. North Garrity Blvd. & 16th Ave. North
Garrity Blvd. & 39th Ave. North Garrity Blvd. & Kings Rd.
Greenhurst Rd. & Southside Rd. Hawaii Ave. & Holly St.
High St. & Yale St. Locust Ln. & 12th Ave. South (SH-45) Ustick Rd. & Franklin Blvd. Ustick Road & 11th Ave. North
Ustick Rd. & Madison Rd. Ustick Road & Star Rd. Ustick Road & Can Ada Rd. Victory Rd. & Happy Valley Rd.
Analysis Year
Intersection Control L
T
R
L
T
R
L
T
R
L
T
R
Existing
Signal
1
1
sh
1
1
sh
1
2
sh
1
2
sh
2035
Signal
2
2
sh
1
1
sh
1
2
sh
1
2
sh
Existing
Signal
1
2
sh
1
2
sh
1
1
0
1
1
0
2035
Signal
1
2
1
1
2
1
2
1
0
1
2
0
Existing
AWSC
sh
1
sh
sh
1
sh
sh
1
sh
2035
Signal
1
2
sh
1
1
1
1
1
1
Existing
AWSC
sh
1
sh
sh
1
sh
sh
1
sh
1
2
sh
1
1
1
1
1
1
sh
1
sh
sh
1
sh
sh
1
sh
1
1
1
Fig. 2-3B
1
1
1
Fig. 2-3B
1
1
1
1
1
sh
1
1
1
NI
1
1
sh
NI
1
1
1
sh
2
sh
sh
2
sh
NI
sh
2
sh
NI
sh
2
sh
sh
1
2
1
2
sh
2
2
Sh
1
2
1
sh
1
free
sh
1
sh
Fig. 3-5C
sh
1
free
sh
1
sh
1
1
sh
NI
1
1
sh
1
1
sh
NI
1
1
1
1
1
sh
1
1
sh
1
1
sh
NI
1
1
sh
0
0
0
NI
0
0
0
1
1
sh
1
2
sh
sh
1
sh
sh
1
sh
sh
1
sh
1
1
sh
1
1
2035
Signal
Existing
AWSC
2035
Signal
1
Existing
AWSC
2035
Signal
Existing 2035
Figure Reference
East Bound
1
2
sh
1
2
sh
TWSC
sh
1
1
Signal
1
1
sh
Existing
Signal
sh
1
1
2035
Signal
1
1
sh
Existing
Signal
1
2
sh
2035
Signal
1
2
sh
Existing
TWSC
1
2
1
2035
Signal
1
2
1
Existing
Signal
1
2
1
2035
Signal
1
2
1
Existing
Signal
1
1
sh
2035
Signal
1
1
1
Existing
TWSC
sh
1
sh
2035
Signal
sh
1
sh
Existing
TWSC
sh
1
0
2035
Signal
sh
1
0
Existing
TWSC
sh
1
sh
2035
Signal
1
1
1
Existing
AWSC
sh
1
1
2035
Signal
1
2
sh
Existing
TWSC
sh
1
sh
2035
Signal
1
2
sh
Existing
TWSC
sh
1
sh
2035
Signal
sh
1
sh
Existing
TWSC
sh
1
sh
2035
Signal
sh
1
sh
Existing
AWSC
sh
1
sh
2035
Signal
1
2
sh
Existing
TWSC
sh
1
sh
1
2
sh
2035
Signal
1
1
Fig. 3-5C
Fig 3-5B
Figure Reference
West Bound
sh
1
sh
1
2
sh
sh
1
sh
1
2
sh
sh
1
sh
Fig. 2-3B
1
1
1
1
2
sh
NI
1
2
sh
0
0
0
0
0
0
2
sh
1
2
2
sh
1
2
1
NI
2
2
sh
1
2
sh
NI
1
2
sh
1
2
1
NI
1
2
1
1
1
sh
1
1
1
sh
1
sh
NI
sh
1
sh
0
1
1
NI
0
1
1
sh
1
sh
1
1
1
sh
1
sh
1
2
sh
sh
1
sh
1
2
sh
sh
1
sh
sh
1
sh
sh
1
sh
sh
1
sh
sh
1
sh
1
2
sh
sh
1
sh
1
2
sh
Fig. 3-5A
Fig. 3-5A
Fig. 2-3A
Fig. 2-3A
Fig. 2-3B
Fig. 2-3B
Fig. 3-5A
Fig. 3-5A
NI
NI
Fig. 3-5A
Fig. 3-5A
NI
Fig 3-5B
Fig. 7-5A
Fig. 3-5A
Fig. 3-5C
Fig. 2-3B
Fig. 2-3B
Fig. 3-5A
Fig. 3-5A
NI
NI
Fig. 3-5A
Fig. 3-5A
Figure Reference
North Bound
sh
1
sh
sh
1
sh
sh
1
sh
sh
1
sh
sh
1
sh
sh
1
sh
sh
1
sh
1
1
1
1
NI
Fig. 2-3B
Fig. 2-3B
Fig. 2-3B
Fig. 3-5C
NI
South Bound
sh
1
sh
NI
1
1
sh
1
1
sh
Fig. 2-3B
1
1
sh
1
1
sh
1
1
sh
1
1
sh
NI
1
1
sh
1
1
sh
NI
1
1
sh
1
1
sh
1
2
sh
sh
1
sh
1
1
sh
sh
1
sh
Fig. 2-3A
sh
1
sh
sh
1
sh
NI
sh
1
sh
sh
1
sh
NI
sh
1
sh
sh
1
sh
sh
1
sh
sh
1
sh
1
1
NI
Fig. 3-5A
NI
NI
Fig. 2-3B
1
Figure Reference
Year Deficient
NI
2025
Fig. 2-3B
2010
Fig. 2-3B
2010
Fig. 2-3B
2010
Fig. 2-3B
2010
NI
2030
NI
2010
Fig 3-5B
2010
NI
2010
Fig. 2-3A
2015
NI
2010
NI
2015
NI
2020
NI
2010
Fig. 3-5A
2020
Fig. 2-3A
2010
NI
2010
NI
2010
NI
2010
NI
2010
Fig. 2-3B
2020
2
2
Sh = Shared turning movement with through lane. Free = Free running movement not controlled by signal. 0 = No approach lane. NI = No Geometric Improvement. Intersection passes all screening criteria for a Dual Lane Roundabout. Based on roadway need, not HCS+
30
PLANNING LEVEL INTERSECTION LEGS 3 - LANE ARTERIAL Nampa Citywide Transportation Plan
100’
100’
3A
3B
1 LEFT TURN LANE
1 LEFT TURN LANE
1 SHARED RIGHT/THRU LANE
1 THRU LANE 1 RIGHT TURN LANE
TAPER DETAIL LAYOUT
TAPER RATE
TAPER LENGTH
NOTE: AREA
3A
---
---
---
3B
8:1
96’
.05 Ac
Intersections are designed based on planning
31
level roadway sections presented in Table 10. Features present within the right-of-way are
I
D
A
H
O
subject to the citys design policies and standards.
FIGURE 2
PLANNING LEVEL INTERSECTION LEGS 5 - LANE ARTERIAL Nampa Citywide Transportation Plan
100’
112’
112’
125’
5A
5B
5C
5D
1 LEFT TURN LANE
1 LEFT TURN LANE
2 LEFT TURN LANE
2 LEFT TURN LANE
1 THRU LANE
2 THRU LANE
1 THRU LANE
2 THRU LANE
1 SHARED RIGHT/THRU LANE
1 RIGHT TURN LANE
1 SHARED RIGHT/THRU LANE
TAPER DETAIL
I
D
A
H
O
LAYOUT
TAPER RATE
TAPER LENGTH
AREA
5A
---
---
---
5B
8:1
96’
.06 Ac
5C
66:1 avg
792’
.19 Ac
5D
33:1 avg
802’
.24 Ac
NOTE: Intersections are designed based on planning
32
level roadway sections presented in Table 10. Features present within the right-of-way are subject to the citys design policies and standards.
FIGURE 3
PLANNING LEVEL INTERSECTION LEGS 7 - LANE ARTERIAL Nampa Citywide Transportation Plan
125’
125’
7A
7B
1 LEFT TURN LANE
1 LEFT TURN LANE
2 THRU LANE
3 THRU LANE
1 SHARED RIGHT/THRU LANE
1 RIGHT TURN LANE
TAPER DETAIL LAYOUT
I
D
A
H
O
TAPER RATE
TAPER LENGTH
NOTE: AREA
7A
---
---
---
7B
31:6 avg
633’
.19 Ac
Intersections are designed based on planning
33
level roadway sections presented in Table 10. Features present within the right-of-way are subject to the citys design policies and standards.
FIGURE 4
PLANNING LEVEL INTERSECTION LEGS 7 - LANE ARTERIAL Nampa Citywide Transportation Plan
125’
140’
7C
7D
2 LEFT TURN LANE
2 LEFT TURN LANE
2 THRU LANE
3 THRU LANE
1 SHARED RIGHT/THRU LANE
1 RIGHT TURN LANE
TAPER DETAIL LAYOUT
I
D
A
H
O
TAPER RATE
TAPER LENGTH
NOTE: AREA
7C
50.4:1 avg
1008’
.36 Ac
7D
31.6:1 avg
1012’
.44 Ac
Intersections are designed based on planning
34
level roadway sections presented in Table 10. Features present within the right-of-way are subject to the citys design policies and standards.
FIGURE 5
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
General Arterial Intersections Forecasted peak hour approach volumes were compared to the threshold volumes developed for the various types of intersections that exist in the study area (Tables 11 and 12). Lane configurations used in the analysis for the intersection approaches were based on recommendations from the roadway needs analysis. If the forecasted approach volumes exceed the LOS D threshold, then the intersection was considered in need of improvement and included on the project list for the year it exceeded the threshold. All improvement Needs are based on the 2035 demand. No interim improvements are recommended (i.e. improving an intersection from a TWSC to a single lane roundabout configuration in 2015 and then to a dual lane roundabout configuration in 2035). Existing stop-controlled intersections were screened to determine if a roundabout improvement is feasible and/or practical. If the intersection is currently signalized, roundabouts were not considered. Signal control was recommended for those intersections that did not meet all of the roundabout screening criteria. Intersections that met the screening criteria for roundabouts were analyzed by comparing forecasted peak hour approach volumes to the roundabout planning thresholds (2,090 vehicles per hour for a single-lane roundabout and 4,180 vehicles per hour for a dual lane roundabout). If the forecasted peak hour volumes were below the threshold volumes, a roundabout was recommended. Based on the methodologies discussed, there are several arterial intersection improvements needed to accommodate 2035 travel demand. Tables 15 through 20 summarize intersection improvements needed by 2035. These are in addition to the specific intersections analyzed in the previous section. However all of the intersections from the pervious section are also included in these tables. Intersection needs specific to each region within the study area are provided in Appendix A.
35
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 15: 2010 Intersection Improvement Needs Intersection
2nd St. South 2nd St. South 3rd St. South (I-84 Bus.) 3rd St. South (I-84 Bus.) 7th St. South 7th St. South Amity Rd.* Caldwell Blvd. (I-84 Bus.) Caldwell Blvd. (I-84 Bus.) Cherry Ln.1 Cherry Ln.1 Cherry Ln.2 Davis Ave. Garrity Blvd. (I-84 Bus.) Garrity Blvd. (I-84 Bus.) Garrity Blvd. (I-84 Bus.) Garrity Blvd. (I-84 Bus.) Greenhurst Rd.1, 4 Greenhurst Rd.4 High St. Homedale Rd. Karcher Ave. (SH-55) Karcher Ave. (SH-55) Karcher Ave. (SH-55) Karcher Ave. (SH-55) Lake Lowell Ave.4 Lone Star Rd.4 Marketplace Blvd. Orchard Ave. Orchard Ave.2, 4 Roosevelt Ave.1, 4 Smith Ave. US 20/26 Ustick Rd.1 Ustick Rd.1 Ustick Rd.1 Ustick Rd.1 Ustick Rd.1
Victory Rd.2 Victory Rd.4
11th Ave. South (I-84 Bus.) Northside Blvd. 12th Ave. South (SH-45) Northside Blvd. 11th Ave. South 12th Ave. South (SH-45) Robinson Rd. Middleton Rd. Midland Blvd. Can-Ada Rd. Franklin Blvd. Northside Blvd. Yale St. 11th Ave. North 16th Ave. North Kings Rd. Stamm Lane Happy Valley Rd. Robinson Rd. Yale St. Caldwell Blvd. (I-84 Bus.) Caldwell Blvd. (I-84 Bus.) Cassia St. Middleton Rd. Midway Rd. Midland Blvd. Midland Blvd. Midland Blvd. Caldwell Blvd. (I-84 Bus.) Middleton Rd. Midland Blvd. Midland Blvd. Can-Ada Rd. 11th Ave. North Can-Ada Rd. Franklin Blvd. Madison Rd. Star Rd. Kings Rd. Happy Valley Rd.
Needed Improvement
Add turn lanes Add lanes Add turn lanes Add lanes Add lanes Add turn lanes Dual lane roundabout Add turn lanes Add turn lanes Add signal and turn lanes Add signal and turn lanes Add signal and turn lanes Add signal Add turn lanes Add turn lanes Add turn lanes Add turn lanes Dual lane roundabout Dual lane roundabout Add signal Add turn lanes Add turn lanes Add turn lanes Add turn lanes Add signal Single lane roundabout Single lane roundabout Add lanes Add turn lanes Single lane roundabout Add signal Add turn lanes Add signal and turn lanes Add signal and turn lanes Add signal and turn lanes Add signal and turn lanes Add signal Add signal and turn lanes Dual lane roundabout Dual lane roundabout
Indicates ITD jurisdiction
36
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO 1
3 4
Shared jurisdiction with local Highway District 2 Local Highway District
Intersection met all screening criteria for a dual lane roundabout
Existing signal warrant analysis completed, shows need for improvements with current volumes
Table 16: 2015 Intersection Improvement Needs Intersection
2nd St. South
12th Ave. South (SH-45)
Birch Ln.
Franklin Blvd.
Cherry Ln.
1
Midland Blvd.
Needed Improvement
Add turn lanes Add signal & turn lanes Add lanes
Cherry Ln.2,4
Star Rd.
Dual lane roundabout
Franklin Rd.1,4
Star Rd.
Dual lane roundabout
Garrity Blvd. (I-84 Bus.)
39th Ave. North
Add signal & turn lanes
Greenhurst Rd.
1
Midland Blvd.
Single lane roundabout
Greenhurst Rd.
1
Southside Blvd.
Add turn lanes
Iowa Ave.
Midland Blvd.
Add signal
Karcher Rd.
Franklin Blvd.
Dual lane roundabout
US 20/26
11th Ave. North
Add signal & turn lanes
US 20/26
Franklin Blvd.
Add signal & turn lanes
US 20/26
Madison Rd.
Add signal & turn lanes
Northside Blvd.
Add signal & turn lanes
McDermott Rd.
Add signal & turn lanes
US 20/26 Ustick Rd.
1
Indicates ITD jurisdiction 1 Shared jurisdiction with local Highway District 2 Local Highway District 3 Intersection met all screening criteria for a dual lane roundabout 4
Existing signal warrant analysis completed, shows need for improvements with current volumes
37
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 17: 2020 Intersection Improvement Needs Intersection
Needed Improvement
2nd St. South
16th Ave. South
Add turn lanes
3rd St. South
7th Ave. South
Add signal
3rd Street South (I-84 Bus.)
11th Ave. South (I-84 Bus.)
Add lanes
Birch Ln.
11th Ave. North
Add signal
11th Ave. North
Dual lane roundabout
Cherry Ln.
1
Hawaii Ave.
Holly St.
Karcher Connector
Midland Blvd.
Add signal Add turn lanes
Locust Ln.
12th Ave. South (SH-45)
Locust Ln.2
Robinson Rd.
Single lane roundabout
Ustick Rd.1
Midland Blvd.
Add signal & turn lanes
Northside Blvd.
Add signal & turn lanes
Ustick Rd.
1, †
Add signal
Indicates ITD jurisdiction 1 Shared jurisdiction with local Highway District 2 Local Highway District †Year of need based on roadway improvement
38
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 18: 2025 Intersection Improvement Needs Intersection
Needed Improvement
2nd St. South
7th Ave. South
Add signal & turn lanes
3rd St. North
16th Ave. South
Add turn lanes
3rd St. South
16th Ave. South
Add turn lanes
7th St. South
7th Ave. South
Add signal
2
Happy Valley Rd.
Add signal & turn lanes
2
Robinson Rd.
Single lane roundabout
Airport Rd. Airport Rd. Amity Rd.
1
Happy Valley Rd.
Dual lane roundabout
Amity Rd.
1
McDermott Rd.
Dual lane roundabout
Amity Rd.
Powerline Rd.
Dual lane roundabout
Cherry Ln.1
McDermott Rd.
Add signal
Flamingo Ave. Franklin Rd.
Iowa Ave. Kuna Rd.
2
Single lane roundabout
McDermott Rd.
Add signal & turn lanes
Middleton Rd.
1
Greenhurst Rd.
1
2
Robinson Rd.
Dual lane roundabout
Middleton Rd.
Single lane roundabout
Southside Blvd.
Single lane roundabout
Locust Ln.
1
McDermott Rd.
Add signal
Locust Ln.
1
Southside Blvd.
Add signal
Lone Star Rd.
Canyon St. East†
Add turn lanes
Lone Star Rd.
Canyon St. West†
Add turn lanes
Orchard Ave.
1
Lake Ave.
Single lane roundabout
Victory Rd.
2
Robinson Rd.
Dual lane roundabout
Victory Rd.
1
McDermott Rd.
Dual lane roundabout
Indicates ITD jurisdiction 1 Shared jurisdiction with local Highway District 2 Local Highway District † Closely spaced “T” intersections along Lone Star Road
39
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 19: 2030 Intersection Improvement Needs Intersection
Needed Improvement
Add signal3
Colorado Ave.
Holly St.
Greenhurst Rd.1
Sunnyridge Rd./Holly St.
Add turn lanes
S. Powerline Rd.
Add turn lanes
Greenhurst Rd. Lone Star Rd.
1
1
Smith Ave.
Middleton Rd.
Single lane roundabout
Middleton Rd.
Single lane roundabout
Indicates ITD jurisdiction 1 Shared jurisdiction with local Highway District 2 Local Highway District 3 Intersection met all screening criteria for a dual lane roundabout
Table 20: 2035 Intersection Improvement Needs Intersection
Needed Improvement
Bowmont/KunaMora Rd.2
Southside Blvd.
Iowa Ave.
12th Ave. South (SH-45)
Add Turn Lanes
Lake Lowell Ave.
12th Ave. South (SH-45)
Add Turn Lanes
Lake Lowell Ave. Lone Star Rd.
2
1
Single Lane Roundabout
Middleton Rd.
Single Lane Roundabout
Lake Ave.
Single Lane Roundabout
Indicates ITD jurisdiction 1 Shared jurisdiction with local Highway District 2 Local Highway District
Community-Based Needs Community-based needs were identified through a solicitation process that utilized the project website and the project’s Community Advisory Committee (CAC). Deficiencies in the transportation system were identified using observations made by stakeholders. Table 21 lists the identified needs. For planning purposes, it is assumed all of the needs identified are required in the next 5 to 10 years. Many suggestions were related to bicycle, pedestrian and public transportation needs.
40
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table 21: Community Identified Needs ID #
Location
Project Description
1
01 Street South to 7th Street South; 11th Avenue South to 16th Avenue South
Upgrade signal controllers on all Downtown signals. Install cameras and new heads as required. Interconnect all cameras and signals to a newlyestablished traffic control center at Traffic Division.
2
Synchronize traffic signals
15
02nd Street South and 03rd Street South at intersections from Yale to Canyon 03rd Street North & Victory Road 03rd Street North parallel to Indian Creek 11th Avenue North 11th Avenue North 11th Avenue North near Sugar Street 11th Avenue North & Garrity Boulevard & Franklin Boulevard 12th Avenue Road & Dooley Lane 12th Avenue Road & Locust Lane 12th Avenue Road from Greenhurst Road to Downtown 12th Avenue South & Iowa Street 12th Avenue South at Paul's market Amity Avenue, from Midland Boulevard on the west into Ada County Caldwell Boulevard at the Canyon County Center
16 17
Caldwell Boulevard at the Canyon County Center Cherry Lane
18
Citywide
19
Citywide
3 4 5 6 7 8 9 10 11 12 13 14
st
Add a walkway or bicycle path through the RR underpass. Install pathway/bicycle signage for this pathway Widen section between Cherry Lane and Ustick Road to four lanes Widen section between I-84 overpass and Cherry Lane to four lanes. Replace/smooth RR crossing Improve Intersection Install a traffic signal Install a traffic signal Add bicycle lanes Force right-in-right-out on Iowa at the Blimpies Implement access control and limit number of entries/exits Widen Amity Avenue to four or five lanes Modify City Bus route to provide direct access to the Canyon County Center rather than dropping students off across the Boulevard from campus Reduce traffic speed and install a pedestrian crosswalk Re-align roadway east of Middleton Road to improve the Cherry Lane Middleton Road intersection. Perhaps use right-of-way from adjacent subdivision up to Laster Lane Allow all students to ride the bus for free with proper identification, including CWI and BSU students Construct bus shelters at ValleyRide bus stops
41
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
ID #
Location
20
Citywide
21
Citywide
22
Citywide
23 24
Citywide Citywide
25 26 27 28
Citywide Citywide Citywide Citywide
29
Davis Street
30
Downtown
31
Downtown
32
Downtown from the South
33
East-west arterials between Nampa and Meridian (Franklin Road, Cherry Lane, Amity Road, etc.). Fern Street to 18th Avenue South to 1st Street South Garrity Boulevard past I-84 to Birch Lane Greenhurst Road, between Midland and Happy Valley
34 35 36 37
Greenhurst Road, between WalMart's south parking lot and Sunnybrook Drive
Project Description Create a traffic operations center to centralize management of coordinated signals. Design, create and install a consistent signage system for bicycle paths and lanes throughout the City. Establish a standard practice that City staff communicates with Valley Regional Transit whenever roadways or sidewalks are getting maintenance or other improvements near existing or proposed bus stops. Increase community awareness of existing bus routes. Install bicycle parking at all Park-and-Ride lots to facilitate multi-modal transportation. Install bus benches at all bus stops. Locate and construct a Bus maintenance facility in Nampa Locate and construct two Bus transfer centers in Nampa Sweep excess stone from chip sealing, including what is on sidewalks and bike ways Eliminate left-in-left-out capability at Yale or terminate connection with Yale and cul-de-sac Davis Address cycling as a legitimate transportation option in the Downtown Revitalization Plan. Establish signals control in Downtown to implement smoother bicycling flow Create a trail/pathway/bike lane project to provide continuous nonvehicular access via Iowa, Chicago and 2nd Street South or via the abandoned rail line Designate, create and sign an inter-city bicycle route along one or more of these corridors. Create continuous on-street bicycle lanes from NNU to downtown Coordinate signal timing to smooth traffic flow Install sidewalks and bike lanes to increase safety for pedestrians and bicyclists Install a pedestrian/bicyclist crosswalk
42
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
ID #
Location
Project Description
38 39 40
Happy Valley Road & Amity Avenue Happy Valley Road & UPRR Happy Valley Road & Victory Road
Add second set of lanes to roundabout Construct overpass (when traffic warrants) Construct roundabout approximately 500' south of the current intersection (approximately 12' lower elevation) and depress Happy Valley through the existing intersection).
41 42 43 44
Holly Street Holly Street & Roosevelt Avenue; Holly Street & Hawaii Street Holly Street & Colorado (Amity Avenue) Holly Street to Fern Street to Holly Street
45
Holly Street to Fern Street to Holly Street
46 47
Holly Street to Fern Street to Holly Street Holly Street, Sheridan Avenue, Bird Avenue, Fern Street and Colorado Avenue Idaho Center Boulevard
Add bicycle lanes Create and install University District monument signage at entry points into the district Install traffic signal or roundabout. Modify the re-named University Boulevard to develop the streetscape, install city standard decorative lighting and generally establish a "boulevard" feel Modify the re-named University Boulevard to reduce it to two travel lanes, a median turn lane (landscaped where possible), and bicycle lanes on both sides. Rename an existing street to "University Boulevard". Add pedestrian crosswalks around NNU campus
48 49 50 51
52 53
Idaho Center Boulevard immediately north of the westbound I-84 on-ramp Idaho Center Boulevard/Can-Ada Road & Cherry Lane Iowa Avenue to Midland Boulevard, then Midland Boulevard to Caldwell Boulevard. Lake Lowell Avenue from 12th Avenue Road to Midway. Iowa Avenue, just west of 12th Avenue Road Irrigation canal between Iowa Avenue and Greenhurst Road.
Rebuild and widen section between Birch Lane and Cherry Lane to four lanes Extend the far right discontinuous southbound lane the remaining few feet to make it a free-flow right turn onto the I-84 on-ramp Improve traffic flow through this intersection Add bicycle lanes and signs.
Add sidewalks (or just widen the street surface) on a section that has no safe walking/riding space. Expand the ability for pedestrians and bicyclists to move between subdivisions via paths/green belts, including bridges across irrigation canals
43
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
ID #
Location
Project Description
54
Karcher Road & Middleton Road intersection and Karcher Road between N. Cassia Street and Midway Road.
Widen Karcher Rd. at, and around Karcher/Middleton intersection. Expand to 4 lanes between N. Cassia St. and Midway Rd. Middleton Rd. could also benefit from widening near the Karcher intersection.
55
Kings Road & Victory Road
56 57
Kings Road from the RR overpass to Garrity Boulevard. Lake Lowell Avenue from 12th Avenue Road to Midland Boulevard Lincoln Avenue, from Canyon to South Powerline
Expand Kings Road due to congestion, especially school traffic for Endeavor Elementary. Add bicycle lanes and signs. Do whatever is necessary to improve safety for bicyclists and pedestrians. Make Lincoln Avenue a priority roadway with center striping and signals at the intersections of 12th Avenue Road and 16th Avenue South. Stripe bicycle lanes on both sides of the road.
58 59
64 65
Lone Star Road east of Midland Boulevard all the way into Downtown Middleton Road Middleton Road & Orchard Avenue Middleton Road & Lone Star Road Middleton Road between Smith Avenue and Lone Star Road Middleton Road from Roosevelt to Karcher Midland Boulevard
66
Midland Boulevard and Smith Avenue.
67
Midland Boulevard from Greenhurst Road to Caldwell Boulevard Midland Boulevard from Greenhurst Road to Caldwell Boulevard Near existing bus routes NNU Neighborhood District Pheasant Hollow Subdivision and many places on Greenhurst Road, Southside and Amity Avenue Ruth Lane between 12th Avenue Road on the west and Sunnyridge on the east.
60 61 62 63
68 69 70 71 72
Add bicycle lanes wherever possible Construct roundabout Widen culvert and intersection capacity Install sidewalk Connect existing sidewalks into a continuous sidewalk Rebuild section between Cherry lane and Ustick; Widen intersection of Midland Boulevard and Ustick Road Install better traffic control to eliminate cut-through traffic that endangers school children Add continuous bicycle lanes or make sidewalks continuous on at least one side of the street Expand Midland Boulevard to four lanes Improve pedestrian network connected to transit stops Improve sidewalks Add sidewalks Widen Ruth Lane to accommodate pedestrians and bikes.
44
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
ID # 73 74 75
Location
77 78 79
Stanford Street and Deer Flat Nampa Canal Street surfaces Sunnyridge Road between E. Maryland Street and the Wilson Trail Sunnyridge Road between Massachusetts Street and Stoney Meadow Drive and on the east side of Sunnyridge right by Greenhurst Road. The Marketplace, especially around the CostCo area The Marketplace, especially around the CostCo area Throughout central city
80
Union Pacific Railroad Tracks
81
Ustick Road
76
Project Description Improve safety for school children crossing the canal Raise sunken water/sewer covers to same level as street surface Create a safe connection for pedestrians and bicyclists to access the Wilson Trail from the north (sidewalks or bike lane or ??) Add sidewalks to eliminate gaps, especially for school student safety.
Add bicycle lanes and signs. Add bus service. Increase bus service in neighborhoods that are quite a distance off of 12th Avenue or Caldwell Boulevard Create dedicated bicycle and pedestrian access across the railroad in the vicinity of Downtown Preserve right-of-way for future expansion
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Next Steps Cumulatively, the capacity-based needs analysis resulted in the identification of approximately 122 miles of roadway improvements and 120 intersection improvements. Additionally, 81 transportation system needs were identified by members of the community. All of the identified needs will be categorized and prioritized to compete for the available funding. To do this, ranking criteria will be developed and estimated project costs documented. Prioritized projects and their estimated costs will be applied to the estimates of available funding to develop a capital improvement plan for the City of Nampa. This will be a critical element of the overall Citywide Transportation Plan.
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
References: Ada County Highway District. Capital Improvements Plan (CIP), Page 7, Table C-4. (624-2009) http://www.achd.ada.id.us/PDF/CIP/Adopted%20CIP/CIP%20Text_6-2409.pdf Ada County Highway District. FY2009-2013 Northern Ada County Transportation Improvement Program (COMPASS report # 13-2008) Ada County Highway District (ACHD). Ada County Roundabout Study: Draft Roundabout Application Guidelines for Ada County, 2007. American Association of State Highway and Transportation Officials (AASHTO). A Policy on Geometric Design of Highways and Streets. Washington, D.C.: AASHTO, 2004. (Also known as the AASHTO “Green Book”) Chapter 4-Cross Section Elements Chapter 6-Collector Roads and Streets (Urban) Chapter 7-Rural and Urban Arterials (Urban) American Association of State Highway and Transportation Officials (AASHTO). Guide for the Development of Bicycle Facilities. Chapter 2, Design; Washington, D.C.: AASHTO, 1999. Canyon Highway District Website, Forms and Maps, Map of Canyon County Highway Districts; September 2009. http://canyonhd4.org/resources.php COMPASS; Communities in Motion, Chapter 4; (8-21-2006) www.comminitiesinmotion.org/documents/datareports/chapter4.pdf COMPASS; 2002Travel Demand Forecast Model Calibration Report for Ada and Canyon Counties (report No. 09-2006), June 22, 2006. http://www.compassidaho.org/documents/prodserv/model/2002%20calibration%20report.pdf
City of Nampa, Demographic Forecast and Land Use Analysis for the Nampa Study Area and South Study Areas 2007-2030; June 2008 City of Nampa, Subdivision Process and Policy Manual, Exhibit B Federal Highway Administration, Operation of Roundabouts: An Informational Guide, Exhibits 4-6, 4-9, and 4-10, Chapter 4, Pub. No. FHWA-RD-00-067 (2000). http://www.tfhrc.gov/safety/00068.htm
Florida Department of Transportation (FDOT), Quality/Level of Service Handbook; Generalized Tables, 2002. http://www.dot.state.fl.us/planning/systems/sm/los/pdfs/QLOS2002.pdf 47
NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Highway Capacity Manual; HCM 2000, Chapter 10 Highway Capacity Software Version 5.21; McTrans Center, University of Florida (2005) http://mctrans.ce.ufl.edu/hcs/hcsplus/
Institute of Transportation Engineers, Transportation Planning Handbook, 2nd Edition, 2004. National Cooperative Highway Research Program, NCHRP 255 (Highway Traffic Data for Urbanized Area Project Planning and Design, Chapter 8). Transportation Research Board of the National Academies. Highway Capacity Manual, 2000. Transportation Research Board of the National Academies, Highway Traffic Data for Urbanized Area Project Planning and Design (NCHRP Repot 255); Chapter 8, December 1982.
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Appendix A: Needs Assessment
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table A-1 North Region Roadway Improvement Needs Roadway
Location
Cherry Ln. Franklin Rd. US 20/26 Ustick Rd. 11th Ave. North Can-Ada Rd. Franklin Blvd. Franklin Blvd. Idaho Center Blvd. McDermott Rd. Midland Blvd. Northside Blvd. Star Rd.
Midland Blvd. to McDermott Rd. Gate Rd. to McDermott Rd. Madison Rd. to Can-Ada Rd. Midland Blvd. to McDermott Rd. I-84 to Ustick Rd. Birch Ln. to US 20/26 I-84 to Karcher Rd. Karcher Rd. to Linden St. I-84 to Birch Ln. I-84 to Ustick Rd. Marketplace Blvd. to Ustick Rd. Karcher Rd. to Ustick Rd. I-84 to Ustick Rd.
Segment length (miles)
Current # of lanes
2035 # of lanes
Year Deficient
6.75 1.50 2.50 6.00 2.00 4.00 0.50 3.00 1.50 2.50 1.75 2.25 2.50
2 2 2 2 2 2 5 2 5 2 2 2 2
5 5 5 6 5 5 6 5 6 3 5 3 5
2015 2015 2010 2035 2025 2025 2030 2015 2030 2025 2015 2025 2025
Table A-2: East Region Roadway Improvement Needs Roadway
Location
Airport Rd. Garrity Blvd. Victory Rd. Happy Valley Rd. Robinson Rd.
Kings Rd. to McDermott Rd. Sugar St. to I-84 Sugar St. to McDermott Rd. Amity Rd. to Stamm Ln. Victory Rd. to I-84
Segment length (miles)
Current # of lanes
2035 # of lanes
Year Deficient
3.20 1.70 3.50 2.25 1.60
2 5 2 2 2
3 6 5 3 3
2030 2010 2020 2030 2030
Table A-3: South Region Roadway Improvement Needs Roadway
Location
Amity Rd. Amity Rd. Greenhurst Rd. Greenhurst Rd. Greenhurst Rd. Kuna Rd. Locust Ln. 12th Ave. South 12th Ave. South Happy Valley Rd. McDermott Rd. Middleton Rd. Midland Blvd. Robinson Rd. Southside Blvd.
Chestnut St. to Southside Blvd. West of Grays Ln. to McDermott Rd. Middleton Rd. to Horton St. Horton St. to Bridgewater Ave. Bridgewater Ave. to McDermott Rd. Track Rd. to McDermott Rd. Midland Blvd. to McDermott Rd. Bowmont Rd. to Lake Shore Dr. Sunrise Rim Rd. to Dooley Ln. Greenhurst Rd. to Amity Rd. Locust Ln. to Amity Rd. Greenhurst Rd. to Lake Lowell Ave. Locust Ln. to Lake Lowell Ave. Lewis Ln. to Amity Rd. Bowmont Rd. to Greenhurst Rd.
Segment length (miles)
Current # of lanes
2035 # of lanes
Year Deficient
1.10 2.60 1.25 3.50 2.60 2.50 6.00 3.50 0.20 1.00 3.30 1.00 2.00 3.10 6.00
2 2 2 2 2 2 2 2 3 2 2 2 2 2 2
5 5 3 3 5 5 5 3 5 5 3 3 3 3 3
2020 2020 2025 2025 2020 2020 2025 2025 2015 2015 2030 2030 2030 2030 2035
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table A-4: Table West Region Roadway Improvement Needs Roadway
Location
Caldwell Blvd. Karcher Rd. (SH-55) Karcher Rd. (SH-55) Lake Ave. Lone Star Rd. Orchard Ave. Middleton Rd.
Homedale Rd. to Canyon St. Midway Rd. to Sundance Rd. Sundance Rd. to I-84 Lake Lowell Ave. to Orchard Ave. Middleton Rd. to Canyon St. Lake Ave. to Caldwell Blvd. Lake Lowell Ave. to I-84
Segment length (miles)
Current # of lanes
2035 # of lanes
Year Deficient
3.00 1.15 0.65 2.25 2.00 3.60 4.15
5 2 2 2 2 2 2
6 5 6 3 3 3 3
2015 2010 2010 2030 2030 2030 2035
Table A-5: Central Region Roadway Improvement Needs Segment length (miles)
Current # of lanes
2035 # of lanes
Year Deficient
16th Ave. North to Sugar St. Yale St. to 16th Ave. South Franklin Blvd. to Sugar St. Canyon St. to Greenleaf St. Greenleaf St. to 1st St. South 3rd St. South to Garrity Blvd. Garrity Blvd. to I-84
0.70 0.80 1.00 0.25 0.60 0.90 1.00
2 3 5 2 2 5 2
5 5 6 5 3 6 3
2025 2030 2020 2020 2030 2020 2035
Roosevelt Ave. to Garrity Blvd.
1.70
4
5
2025
Roadway
Location
3rd St. North 7th St. South Garrity Blvd. Lone Star Rd. 7th Ave. South 11th Ave. South 11th Ave. North 16th Ave. North
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table A-6: Intersection Planning Thresholds from HCM 2000 Exhibit 10-24 Example Service Volumes for Signalized Intersection Maximum Service Volumes (veh/hour) Left Turn Lane Present?
Number of Through Lanes
LOS A
LOS B
LOS C
LOS D
LOS E
Yes Yes Yes
1 2 3
N/A N/A N/A
130 200 N/A
350 860 1230
530 1090 1510
590 1220 1680
Exhibit 10-28 Example of Minor Street Service Volumes for T-Intersections TWSC Minor Street maximum service volume by LOS Major street two-way volume (veh/h) LOS A LOS B LOS C LOS D LOS E 200 110 450 6380 700 760 400 N/A 280 460 530 590 600 N/A 150 320 390 440 800 N/A 40 210 270 320 1,000 N/A N/A 120 180 230 Exhibit 10-29 Example of Minor Street Service Volumes for Four-leg Intersections, TWSC Minor Street maximum service volume by LOS Major street two-way volume (veh/h) LOS A LOS B LOS C LOS D LOS E major street = one lane plus turn pockets, minor street = one lane and no turn pockets 500 N/A 90 220 260 300 1,000 N/A N/A 30 70 100 1,500 N/A N/A N/A N/A N/A Exhibit 10-30 Example of Approach Service Volumes for AWSC Intersections for Single Approach Through Lanes LOS A LOS B LOS C LOS D LOS E 1 170 260 310 340 350 2 180 320 430 480 520
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table A-7: North Region Intersection Improvement Needs Corridor
Intersecting Roadway
Current Control
Needed Improvement
Year Deficient
Birch Lane Birch Lane Cherry Lane Cherry Lane
11th Avenue North Franklin Boulevard 11th Avenue North McDermott Road
AWSC AWSC TWSC TWSC
Signal Control Signal Control/Increase Capacity Dual Lane Roundabout Signal Control
2020 2015 2020 2025
Cherry Lane Franklin Road Franklin Road
Star Road McDermott Road Star Road
AWSC TWSC AWSC
Dual Lane Roundabout Signal Control/Increase Capacity Dual Lane Roundabout
2015 2025 2015
Karcher Connector
Midland Boulevard
Signal
Signal Control/Increase Capacity
2020
Karcher Road US 20/26
Franklin Boulevard 11th Avenue North
AWSC TWSC
Dual Lane Roundabout Signal Control/Increase Capacity
2015 2015
US 20/26
Can-Ada Road
TWSC
Signal Control/Increase Capacity
2010
US 20/26 US 20/26
Franklin Boulevard Madison Road
TWSC TWSC
Signal Control/Increase Capacity Signal Control/Increase Capacity1
2015 2015
US 20/26
Northside Boulevard
TWSC
Signal Control/Increase Capacity
2015
Ustick Road
McDermott Road
TWSC
Signal Control/Increase Capacity
2015
Ustick Road Ustick Road
Midland Boulevard Northside Boulevard
AWSC AWSC
Signal Control/Increase Capacity Signal Control/Increase Capacity
2020 2025
1
Intersections require additional capacity beyond needed roadway improvement (i.e. adding turning lanes)
Table A-8: East Region Intersection Improvement Needs Corridor
Intersecting Roadway
Current Control
Needed Improvement
Year Deficient
Airport Road Airport Road
Happy Valley Road Robinson Road
TWSC TWSC
Signal Control/Increase Capacity Signal Lane Roundabout
2025 2025
Amity Road
Robinson Road
AWSC
Dual Lane Roundabout
2025
Garrity Boulevard Victory Road Victory Road Victory Road 1
Stamm Lane Kings Road McDermott Road Robinson Road
Signal AWSC TWSC TWSC
1
Increase Capacity Dual Lane Roundabout Dual Lane Roundabout Dual Lane Roundabout
2010 2010 2025 2025
Intersections require additional capacity beyond needed roadway improvement (i.e. adding turning lanes)
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Table A-9: South Region Intersection Improvement Needs Intersecting Roadway
Corridor
Current Control
Needed Improvement
Year Deficient
Roundabout
Dual Lane Roundabout
2025
Amity Road
Happy Valley Road
Amity Road Amity Road Amity Road
McDermott Road Powerline Road Robinson Road
TWSC AWSC AWSC
Dual Lane Roundabout Dual Lane Roundabout Dual Lane Roundabout
2025 2025 2025
Bowmont Road
Southside Boulevard
TWSC
Single Lane Roundabout
2035
Greenhurst Road Greenhurst Road Greenhurst Road
Happy Valley Road Holly Street Midland Boulevard
AWSC Signal AWSC
Dual Lane Roundabout Increase Capacity Single Lane Roundabout
2010 2030 2015
Greenhurst Road Iowa Avenue
Robinson Road 12th Avenue South
AWSC Signal
Dual Lane Roundabout Increase Capacity
2025 2035
Iowa Avenue
Middleton Road
AWSC
Single Lane Roundabout
2025
Iowa Avenue Kuna Road
Midland Boulevard Southside Boulevard
AWSC TWSC
Signal Control Single Lane Roundabout
2015 2025
Lake Lowell Avenue
12th Avenue South
Signal
Increase Capacity1
2035
Lake Lowell Avenue Lake Lowell Avenue
Middleton Road Midland Boulevard
AWSC AWSC
Single Lane Roundabout Single Lane Roundabout
2035 2035
Locust Lane Locust Lane Locust Lane
McDermott Road Robinson Road Southside Boulevard
OWSC TWSC TWSC
Signal Control Single Lane Roundabout Signal Control
2025 2020 2025
1
Intersections require additional capacity beyond needed roadway improvement (i.e. adding turning lanes)
Table A-10: West Region Intersection Improvement Needs Corridor
Intersecting Roadway
Current Control
Needed Improvement
Year Deficient
Caldwell Blvd. Caldwell Blvd.
Homedale Rd. Middleton Rd.
Signal Signal
Increase Capacity Increase Capacity
2010 2010
Caldwell Blvd.
Midland Blvd.
Signal
Increase Capacity
2010
Flamingo Ave.
Middleton Rd.
TWSC
Single Lane Roundabout
2025
Karcher Rd. (SH-55) Karcher Rd. (SH-55) Karcher Rd. (SH-55) Karcher Rd. (SH-55)
Caldwell Blvd. Cassia St. Middleton Rd. Midway Rd.
Signal Signal Signal TWSC
Increase Capacity Increase Capacity Increase Capacity1 Signal Control
2010 2010 2010 2010
Lone Star Rd.
Canyon St. East2
OWSC
Increase Capacity
2025
Lone Star Rd. Lone Star Rd. Lone Star Rd. Lone Star Rd.
Canyon St. West2 Lake Ave. Middleton Rd. Midland Blvd.
OWSC AWSC AWSC AWSC
Increase Capacity Single Lane Roundabout Single Lane Roundabout Single Lane Roundabout
2025 2035 2030 2010
Orchard Ave. Orchard Ave. Orchard Ave.
Caldwell Blvd. Lake Ave. Middleton Rd.
Signal TWSC AWSC
Increase Capacity Single Lane Roundabout Single Lane Roundabout
2010 2025 2010
Roosevelt Ave.
Midland Blvd.
AWSC
Signal Control
2010
Smith Ave.
Middleton Rd.
TWSC
Single Lane Roundabout
2030
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NAMPA CITYWIDE TRANSPORTATION PLAN NEEDS ASSESSMENT TECHNICAL MEMO
Smith Ave.
Midland Blvd. 1
OWSC
Increase Capacity
2010
Intersections require additional capacity beyond needed roadway improvement (i.e. adding turning lanes) 2 Canyon Street intersections are two closely spaced “T” intersections
Table A-11: Central Region Intersection Improvement Needs Intersecting Roadway
Corridor 2nd Street South 2nd Street South 2nd Street South 2nd Street South 2nd Street South 3rd Street South 3rd Street South 3rd Street South 7th Street South 7th Street South 1
11th Avenue South 12th Avenue South 16th Avenue South 7th Avenue South Northside Boulevard 12th Avenue South 16th Avenue South 7th Avenue South 7th Avenue South 12th Avenue South
Current Control
Needed Improvement
Year Deficient
Signal Signal Signal TWSC Signal Signal Signal TWSC AWSC Signal
Increase Capacity Increase Capacity Increase Capacity Signal Control/Increase Capacity Increase Capacity Increase Capacity Increase Capacity Signal Control Signal Control/Increase Capacity Increase Capacity
2010 2015 2020 2025 2010 2010 2025 2020 2025 2010
Intersections require additional capacity beyond needed roadway improvement (i.e. adding turning lanes)
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