1. City of Abilene Pavement Condition Survey 2017 Results and Discussion
Fugro Roadware, Inc.
Paul McLandrich
Graduate Engineer
March 23rd, 2017

2. Topics of Discussion
Project Objectives
Project Background and Equipment
The Pavement Condition Index
Network Condition Results
Maintenance Strategies and Costs
Budget Scenarios
Policy Direction Discussion
Next Steps…

3. Project Objectives
Perform a comprehensive pavement condition inventory for all roads within City jurisdiction
629+ Centerline miles
717+ Survey miles
Develop network inventory geographical database (GIS)
Calculate Pavement Condition Index (PCI) for each street
Import condition data into Cartegraph PMS Software
Develop and program long-term pavement maintenance and rehabilitation strategies
Develop budget funding scenarios based on the City’s current budget, and future needs

4. Network breakdown by Functional Classification
Project Background
Network breakdown by Functional Classification

5. Project Background

6. Pavement Condition Index

7. Network Condition Results
Most Common Pavement Distress Types Found in the City of Abilene Pavement Condition Survey
Alligator Cracking
Edge Cracking
Block Cracking
Potholes
Surface Raveling
Different distress are caused by different factors and need to be repaired differently

8. Network Condition Results
Alligator (Fatigue) Cracking
Dense pattern of surface cracks
Cracks go through the full depth of the asphalt
Typically a sign of thin pavement or heavy traffic
Cracks are active
Cracks reappear quickly in thin surfaces
Difficult to repair with out removing a lot of material

9. Network Condition Results
Edge Cracking
Alligator cracking pattern at the pavement edge
Usually caused by lack of material or erosion of base
More common without curb or shoulder
Quickly damages thin surfaces
Localized repairs work for a few years
Deep patching and base repairs before resurfacing

10. Network Condition Results
Block Cracking
Low density cracking that forms rectangular blocks
Typical block size measures 2-6 ft
Cracks don’t often move and are usually covered with a thin pavement surface

11. Network Condition Results
Potholes
Common in deteriorated areas of pavement
Characterized by portions of missing surface
Causes poor riding surface (and complaints)
Temporary repairs don’t last long
Local full depth repairs can be effective

12. Network Condition Results
Surface Raveling
Loose material in the pavement surface
Characterized by a crumbling surface
Not pleasant for bikes and other small wheel traffic
Causes slippery roads
Often repaired with thin surface

13. Network Condition Results
Functional Class
Average PCI
% of Network
Arterial
69.8
16%
Collector
70.8
22%
Local
45.6
62%
Overall Average
50.1
(Borderline “Good”)
PCI Including Capital Improvements = 50.4

14. Network Condition Results
(16%)
(22%)
(62%)

15. Maintenance Strategies and Costs
Pavement Management
The goal of pavement management is to apply the right treatment, to the right pavement, at the right time
Developing an inventory
Collecting consistent, complete, and accurate pavement condition data
Monitoring the network to evaluate deterioration and benefits of treatments
Predict future conditions and costs

16. Maintenance Strategies and Costs
Crack Sealing
Reduces rate of deterioration
Prevents water infiltration
Keeps loose material attached
Used on non-active cracks
Usual life 2-4 years
Cost – $0.84/sq. ft.

17. Maintenance Strategies and Costs
Chip Seal
Prevents water from penetrating road surface
Fill and seals cracks and raveled pavements
Provides a highly ski- resistant surface
Good for low-speed roads
Low cost compared to overlay
Life expectancy 5-7 years
Cost - $0.75/sq. ft.

18. Maintenance Strategies and Costs
Microsurfacing
Similar to a slurry seal
Emulsion without aggregate, “sealant”
Premium aggregate allows for use on high speed roads
Emulsion often contains latex
Fills small ruts
Surface should have limited cracking
Life expectancy 2 to 5 years
Cost - $0.91/sq.ft.

19. Maintenance Strategies and Costs
Patching
Reduces rate of deterioration
Simple fix for problems like potholes
Localized problem repairs
Used as a temporary repair before new surfaces or to address safety concerns
Usual life 2-4 years
Patching - $4/sq. ft.

20. Maintenance Strategies and Costs
Mill & Overlay
Covers complete surface and removes previous defects
Can greatly improve surface smoothness
Can be used to improve structural capacity
Deep environmental distress may still reflect
Usual life years
With regular maintenance!
Cost $4.12/sq. ft.

21. Maintenance Strategies and Costs
Pavement Reconstruction
Usually last choice as it is the most expensive
Removes all defects and allows for longer life
Allows for repair of underlying utilities
Repair or placement of additional granular materials
Complete repair of all issues
Usual life years
With regular maintenance!
Cost - $11.41/sq. ft.

22. Maintenance Strategies and Costs
Budget Inputs – Unit Costs
Treatment
Unit Cost (/ft2)
Impact
Asphalt Pavement (AC)
Crack Sealing
$0.84
PCI increases by 5%
Microsurfacing
$0.91
PCI increases by 30
Chip Seal
$0.85
PCI is set to 90
AC Mill and Overlay
$4.12
PCI is set to 100
Full Depth Reconstruction
$11.41
Concrete Pavement (PCC)
$0.01
Crack Sealing/Joint Repair
$1.22
PCI increases by 8%
Slab Repair/Mud Jacking
$4.01
PCC Pavement Reconstruction
$13.35

23. Maintenance Strategies and Costs
Condition vs. Treatment Cost

24. Maintenance Strategies and Costs
Network Backlog
Surface
Activity
Unit Cost
Total Cost
% Total AC
Crack Seal
$0.84
4,223,297.23 1%
Micro-Surface
$0.91
10,297,690.60 3%
Chip Seal
$0.85
17,137,761.36 5%
Mill and Overlay
$4.12
46,068,640.16
12%
Reconstruction
$11.41
294,137,411.65
78%
Total
$371,864,801.00
PCC
Crk Seal & Joint Repair
$0.01
570,554.24
0.2%
Slab Repair & MudJacking
$1.22
1,876,591.03
0.5%
CPR & Overlay
$4.01
736,178.68
$13.35
2,120,213.44
$5,303,537.39
Total Backlog
$377,168,338.39

25. Budget Scenarios
Results Comparison – Collectors and Arterials

26. Budget Scenarios
Five-year Trend - $700k Annual Budget

27. Budget Scenarios
Five-year Trend - $5M Annual Budget

28. Policy Direction Discussion
Case Study
Worst-first vs. Benefit-Cost Analysis
In a W-F approach, pavement sections are ranked according to their condition score
In the BCA approach, sections are ranked according to their benefit-to-cost ratio
Sections are then selected for treatment according to their ranking until the available budget is depleted
W-F & BCA approaches are compared based on:
Average lane miles in good condition per year
Net backlog of projects at the end of the analysis period
M&R Types
Maintenance: Preventative maintenance (e.g., chip seal, microsurfacing)
Rehabilitation: Light, Medium, & Heavy Rehab. (e.g., mill & overlay)

29. Policy Direction Discussion
Case Study
Worst-first vs. Benefit-Cost Analysis
PM = Preventative Maintenance LR = Light Rehabilitation MR= Medium Rehabilitation HR = Heavy Rehabilitation

30. Policy Direction Discussion
Case Study
Worst-first vs. Benefit-Cost Analysis

31. Policy Direction Discussion
Case Study
Worst-first vs. Benefit-Cost Analysis
W-F tends to favor major rehabilitation projects (very costly projects)
BCA approach tends to favor maintenance projects that are more cost-effective in the long-term
Worst-first Approach
$5 per sq.ft. to raise PCI from 30 to 100
14 PCI Increase per $1 spent (70 PCI / $5)
Benefit-Cost Approach
$1 per sq.ft. to raise PCI from 70 to 100
30 PCI Increase per $1 spent (30 PCI / $1)
When maintenance and rehabilitation share a single combined budget, the worst-first approach produces less lane-miles in good condition and more backlog than the cost benefit approach

32. Questions?