Operations Department

Operations Department Road Rehabilitation Information Session City of Prince George Statistics Population 75,828 (2011) Area Within City Limits ...
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Operations Department Road Rehabilitation

Information Session

City of Prince George Statistics Population

75,828 (2011)

Area Within City Limits

32,040 Ha (123.7 sq.mi.)

Length of Paved Roads

580 km

Length of Gravel Roads

90 km

Length of Sidewalks

184 km

City Bridges / Structures 11

Transportation Hand Outs 2007 – 2011 Capital Road Paving Projects Map Includes Road Resurfacing & enhanced Paving 2012 Transportation Capital Projects Map Road Resurfacing

Micro Surfacing  is a polymer modified cold mix paving system that is a mixture of dense graded aggregate, asphalt emulsion, water and mineral fillers;  will provide a new traveling surface, typically placed on lifts of 9.5mm;  does not add to road structure only protects existing asphalt surface (prolongs life of asphalt);  Micro Surfacing did not perform well on high speed, high volume, deteriorating road (Ospika), but did perform well on a residential street (Nation Crescent).

Cost for Micro Surfacing is $7.00 to $8.00 per square metre Pros Cost effective Life expectancy 5 to 7 years Open to use after a few hours

Cons Surface repair only Does not repair reflective cracking, failed asphalt or potholes. Locally has not performed well on high speed, high volume roads.

May be used to repair wheel ruts Improves skid resistance May be applied in thin lifts (9.5mm) Protects original pavement surface

Nation Crescent - 2005

Thin Lift Overlay  is a 40 to 50mm lift of asphalt placed on existing road with limited remedial work done prior to the new lift being placed;  work done prior to overlaying would consist of pothole patching and filling of any major cracks within the road surface;  adds strength to the existing road structure, but reflective cracking will likely appear through the new lift of asphalt within a couple of years;  candidates for Thin Lift Overlays are roads with good road structure, with only a few minor surface deficiencies, and roads that were left low when constructed;  The enhanced patching program generally uses this procedure.

Cost for Thin Lift Overlay is $22.00 per square metre Pros

Cons

Reasonably cost effective

Existing defects may show on new surface

Allows to re-establish road crown Removes minor wheel ruts Adds to road structure Life expectancy 12-15 years

Does not repair heaves or bumps Some roads may require curb relief milling Does not address sub-base problems

Johnson Street - 2011

Mill and Overlay  removes 50mm of the old asphalt surface and replaces it with new;  milling will remove surface cracks, wheel ruts and minor potholes (less than 50mm deep) and allow the final road elevation not to change which is beneficial for roads with curb and gutter;  Candidates for Mill and Overlay projects are roads with a failing asphalt surface, but a good road structure. Cost for Mill and Overlay is $28.00 per square metre

Pros

Cons

Cost effective

Asphalt surface repair only

Allows to re-establish road crown

Timing – milling contractor availability

Removes surface deficiencies

Does not address sub-base problems

Does change road elevation (curb reveal)

Milled materials are used to surface gravel roads

Ospika Boulevard - 2011

Pulverize and Pave  is the pulverizing of the asphalt and granular base course, compacting and then overlaying with a 50mm lift of crush and a 75mm lift of asphalt;  pulverizing can be to a depth of up to 300mm,although most roads only require 150mm depth to capture the existing road base material and the asphalt surface, so all surface distresses can be removed and the road asphalt surface and granular base course will be new while adding to the overall road structure;  candidates for Pulverize and Pave projects are roads with major surface deficiencies (cracking, rutting, and potholes), but a good road structure. Cost for Pulverize and Pave is $38.00 per square metre

Pros

Cons

Repairs all surface deficiencies, such as cracking, raveling and potholes Allows for re-profiling and minor widening

Isolated sub-base failures may have to be repaired prior to construction Not ideal for roads with curb and gutter

Life expectancy 15 years Adds structural strengths

Old Summit Lake Road - 2011

Full Reconstruction  is the removal of existing surface and all granular materials to competent sub-grade elevation as determined by a Geotechnical Engineer;

 rebuild the road structure based on a Geotechnical report;  we consider this the most labour intensive and costly method for rehabilitating roads that were originally constructed with minimal gravel sub-base and poor sub-grade;  cost for Full Reconstruction varies widely depending on: curb and gutter versus ditches, depth of excavation to suitable sub-grade, amount of landscaping etc.

Cost for Full Reconstruction is estimated between $97.00 and $160.00 per square metre Pros

Cons

Completely new road structure

Very expensive

Ability to change profile, grades, width and drainage

Time and disruption

Life expectancy 15 to 20 years

Usually done on low volume traffic roads

North Blackburn Road - 2007

Hot in Place Asphalt Recycling  is the process where the current asphalt surface is heated, scarified, mixed with new asphalt (typically 15%) and placed as a new surface;  candidates for Hot in Place Recycling are roads with surface problems only. Cost for Hot in Place Asphalt Recycling can be expected around $13.00 per square metre Pros

Cons

Cost effective if done in large amounts

Small projects may not draw interest from contractors

Allows to reestablish crown and road shape

Does not repair sub-base of sub-grade failures

Approximately 15% new material

Difficult to do on roads with manholes and valves

Ospika Boulevard - 2003

Seal Coat  is the process where the existing road surface (gravel or asphalt) is sprayed with emulsified asphalt cement then covered with aggregate;  seal coat provides a waterproof membrane that allows the road surface to shed water preventing it from entering the base material and it also improves skid resistance;  best suited for roads with low traffic volumes;  seal coat may be applied in single or double seal applications depending on current road condition;  candidates for Seal Coat are gravel roads with good structure and low volume asphalt roads with minor surface distresses. Cost for Seal Coat at single seal application can be expected to be $3.50 per square metre and for double seal application $5.00 per square metre.

Pros

Cons

Protects road structure from water

Final surface is not smooth

Improves skid resistance

Does not repair potholes, rutting etc.

Dust control on gravel roads Low initial costs in comparison to thin asphalt overlays

Surface treatment only No local contractors do this type of work

Example of Seal Coat

Foamed Asphalt

 foamed asphalt base stabilization is a roadway recycling process in which all of the pavement and some of the underlying material is pulverized and treated with a foamed additive to produce an improved, stabilized base;  thin layer of granular material is applied to the road surface to establish final grade and road crown;  a layer of hot mix asphalt is applied. Cost for Foamed Asphalt can be expected around $55.00 per square metre Pros

Cons

Removes all asphalt distresses

Not many contractors do this type of work

Increases road structure & strength

Contractor timing & availability Not suitable for roads with curb & gutter or underground utilities Increases road elevation

Minimal traffic disruption

Cranbrook Hill Road - 2008

Interlocking Concrete Paver Surface  Pavers are made of cementitious materials in a quality controlled environment and can be manufactured to be capable of resisting a high degree of freeze-thaw cycles and deicing salts;  provides character/decoration to the travelling surface;  in most cases requires the removal of existing surface and base granular;  requires quality control on the bedding materials and joint sand specifications. Cost for Interlocking Paver Stone Roadway $100.00 to $120.00 per square metre

Pros

Cons

Life expectancy is 25+ years Ease of Installation, does not require substantial equipment to place No pot holing due to the ease of maintenance Variety of colors or laying patterns available, (herringbone recommended for driving surface) Provides traffic calming effect Can be utilized for bridge surfaces

Initial cost is high

George Street - 2011

Asphalt Road Surfacing Options Summary In the 2007 Capital Road Rehabilitation Program the City of Prince George used the Mill and Overlay option twice, the Full Reconstruction method three times, a form of the Pulverize and Pave once, and a procedure similar to the Thin Lift Overlay once. The finished product of all methods used has been good. The Full Reconstruction projects have exceeded the original budget estimates due to varying unforeseen conditions. The Mill and Overlay, Pulverize and Pave, and Asphalt Overlay methods all came in under the original estimates.  With the desire to achieve a new asphalt surface on more lane kilometers it should be considered to move away from Full Reconstruction projects and proceed with more cost effective methods for resurfacing our roads. Some projects will require Full Reconstruction, but we should address the localized areas within the project for Full Reconstruction and utilize a more economical method for the areas of the project that are okay.  The existing road conditions will always dictate the best suited methodology for repair, but to get the most out of our dollars it would be best to consider Mill and Overlay, Thin Lift Overlay, and Pulverize and Pave as the core of our Capital Road Rehabilitation Program.  The other methods have a place in our Capital Road Rehabilitation Program and should always be considered as an option.

Pothole Patching Options

Explanation provided by the Michigan Department of Transportation

Pothole Patching Options Spray Patching Has been utilized on sections of Domano, Ospika & Massey with marginal results. Pros Cons One person No local contractors operation Marginal performance Initial cost of unit

Cold Asphalt Patch Other similar products are solicited annually by various suppliers Pros Cons Cost - $685/tonne + Easy application shipping Performs in most No local availability conditions

Typical Pothole Patching To run 2 shifts, it costs approximately $14,600 per week

Typical Full Size Patch Crew

Major Pothole Patching Ospika Blvd between 22nd Ave and Ferry Ave

Capital & Enhanced Paving Program Cost Breakdown 2004 - 2011 4,000,000 3,500,000 3,000,000

2,500,000

Contracted Other 2,000,000

Contracted Paving

City

1,500,000 1,000,000 500,000

2011

2010

2009

2008

2007

2006

2005

2004

-

Capital & Enhanced Paving Program Cost Breakdown 2004 - 2011 Pothole Statistics Date Range Specific January 1 to May 25

4,000,000 3,500,000 3,000,000

14,000.00 12,000.00

Axis Title

2,500,000 2,000,000

10,000.00

Contracted Other

8,000.00

Contracted Paving 6,000.00

1,500,000 1,000,000

City

4,000.00 2,000.00 0.00

4,546.00

10,038.00

Cracks Metres

1,502.25

386.00

1,471.35

459.50

312.75

2,378.00

2005

2004

-Overlays m2

2011

13,522.00

2010

# of Hot Potholes

500,000

2009

2012 1,517.00

2008

2011 665.00

2007

2010 3,259.00

2006

# of Cold Potholes

Capital & Enhanced Paving Program Cost Breakdown 2004 - 2011 4,000,000

Asphalt Cost Comparison Cost per Tonne

3,500,000 3,000,000

2010

2011

$143.00

$143.00

2012

2,500,000

Prince George

2,000,000

Contracted Other $147.50 Contracted Paving

Okanagan 1,500,000 (Average of 3 Municipalities) 1,000,000

32.0% Less 29.5% Less

500,000

2011

2010

2009

2008

2007

2006

-

2005

30.4% Less

Comparable Comparable 18.9% Less to PG to PG

Vancouver Island

2004

City

Capital & Enhanced Paving Program Cost Breakdown 2004 - 2011

4,000,000

Roads Sidewalks and Bridges Challenges

3,500,000

• Road Rehab funding at $3.5M is ~ 50% of the 3,000,000 desired funding level to maintain current service levels. 2,500,000 Contracted Other

• The effects of inflation on road rehab costs Contracted Paving (~14%/yr for materials) far exceed the consumer City 1,500,000 price index. 2,000,000

1,000,000

• There is limited and inconsistent funding for 500,000 sidewalk maintenance, rehab. and new linkages. 2011

2010

2009

2008

2007

2006

2005

2004

• Foothills Bridge strengthening has been deferred.

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