1. Impact of Heavy Truck Traffic on Pavement Performance
Valbon Latifi
Hani H. Titi
Nicholas Coley
Mohammed Matar
Department of Civil Engineering and Mechanics
University of Wisconsin-Milwaukee
Wednesday, February 26, 2014

2. Introduction Height and Weight Restrictions in Wisconsin: Width: 8’6”
Overweight (OW) = 80,000 lbs
Oversize (OS) = Height: 13’6”
Width: 8’6”
Length: 45’ (Single Unit)
75’ (Tractor-Trailer)
Superheavy (SHL) = 270,000 lbs
Only Single Trip permit records used for analysis.

3. Background
Wisconsin (WI) issued approximately 96,000 single trip permits from June 2007 to June 2013
432 permits were (SHLs)
Only Oversize (OS) permits excluded from analysis (height, width, and length restrictions)

4. Previous Studies
Acimovic (2007) conducted research on reconstructed OSOW corridor in Colorado, discovering rutting occurred less than a year later. Rutting occurred due to repeated and excessive loading of OSOW trucks.
Chatti (2004) stated that rutting damage induced on the pavement by multiple axles increased the number of axles per group increased as well.

5. Research Methodology
Locate corridors in WI with high use of OW and SHL trucks.
Analyze pavement performance with AASHTOWare Pavement ME Design
Build various Axle Load Spectra with baseline traffic and then the addition of OW permitted vehicles
Use Vehicle Class Distribution comparing statewide data to localized data.

6. Permit Fees vs. GVW #2 #3 #1
Three random single trip permits highlighted to see discrepancy in permit fee structure and policy.

7. Permit Fees vs. Trip Length#1 #3

8. Comparison of SHL Fees
Truck
GVW (kips)
Trip Length (mi.)
Fee
Cost per kip
Cost per mile 1
585.6
493
$566
$0.97
$1.15 2
605.0
134
$574
$0.95
$4.28 3
749.0 21
$705
$0.94
$33.57
Single trip permit fees for SHL’s cost approximately $1.00 per kip.
No correlation between distance of trip and permit fee.
Should potential increase in damage imposed by SHL loads be included in permit fees with regards to distance traveled?

9. Case Study (Wisconsin State Highway 140)
12 miles from IL border to I-43 and WI-11
21,613 permits in 6 years
103 SHL permits in 6 years
Bypasses the I-90/I-39 tollway in Illinois
Field survey and 6 hour traffic count were conducted
Courtesy of Google Maps

10. WI-140 Typical Section 2” HMA Overlay 2” HMA
4.5” Aggregate Base Course
A-6 Soil Subgrade
1.5” milled surface and 2” overlay in 1996

11. WI-140 Pavement Condition
July 22, 2013
Severe alligator cracking, rutting, longitudinal cracking, potholes, and shoulder failure.

12. WI-140 Pavement Condition
Obliterated shoulder
Potential shoulder failure due to wide base trucks or large farm equipment.
July 22, 2013

13. OW Vehicles
Photos taken in the field on July 22 and November 4, 2013.

14. Farm Equipment Photos taken on November 4, 2013.
10 passed through in 6 hour traffic count.

15. AASHTOWare
Program created to capture pavement design through the Mechanistic-Empirical Pavement Design Guide (MEPDG).
Unlike previous AASHTO Design Guides, MEPDG is a pavement analysis tool, determining the stresses and when they are projected to occur over the design life.
Three main inputs:
Traffic
Pavement Structure/Material Properties
Climate

16. Traffic Count on WI-140 (07/22/13)
Vehicle Class
Total Count 1 3 2
163 68 4 5 21 6 7 8 9 67 10 11 12 13
 Total
335
2.5 hour count (8:45 am to 11:15 am)
30.1% trucks (Class 4 to 13)
66.3% of the trucks were Class 9
10 marked as OS and potentially OW

17. Traffic Count on WI-140 (11/04/2013)
Vehicle Class
South Bound
North Bound
TOTAL
8:00 am to 10:00 am
10:00 am to 12:00 pm
12:00 pm to 2:00 pm
SB Total
NB Total 1 2 58 54 60
172 71 80 61
212
384 3 25 19 20 64 24 23 66
130 4 5 7 9 6 22 10 43 8 28 26 74 34 31 90
164 11 12 13
 Total
128
125
116
369
154
410
779

18. Traffic Count on WI-140 (11/04/2013)
Vehicle Class
Total Count 1 2
384 3
130 4 5 25 6 43 7 8 9
164 10 11 12 13
 Total
779
6 hour count (8:00 am to 2:00 pm)
33.9% trucks (Class 4 to 13)
62.1% of the trucks were Class 9
15 marked as OS and potentially OW

19. WisDOT’s Vehicle Class Distribution
Rural Principal Arterial - Interstate
Rural Principal Arterial - Other
Rural Minor Arterial
Urban Principal Arterial - Other 4
1.3
3.1
8.3 5
25.8
19.8
31.7
23.4 6
6.1
11.2
9.4
3.7 7
0.3
1.1 3
2.5 8
7.2 11
12.1 9
55.5
50.6
31.9
62.6 10
0.8
1.6
1.7
2.2 1
0.2 12
0.5
0.1 13
1.2
0.4
1.9

20. WisDOT’s Axles per Truck
Vehicle Class
Axle Type
Single
Tandem
Tridem
Quad 4
1.3
0.7 5
2.2 6 1 7
0.4
0.8 8
2.4
0.6 9
1.9 10
1.1 11
4.9
0.1 12 13
1.2
Standard values for WisDOT pavement design using AASHTOWare

21. VCD from WI-140 (11/04/2013)
Vehicle Class
Total Count of Trucks
% of Traffic 4 2
0.76 5 25
9.47 6 43
16.29 7
1.89 8 3
1.14 9
164
62.12 10
3.79 11 12
1.52 13
 Total
264
100
Truck count to be used with AASHTOWare as an alternative to WisDOT standard values.

22. WI-140 Pavement Survey Pavement survey data input in MicroPaver.
Visual distress survey (HS: high severity; MS medium severity)
Pavement survey data input in MicroPaver.
Pavement Condition Index (PCI) ranged from 13 to 17.

23. Contour Map of Rutting
Rutting Depth (in):
Majority of rutting occurring on the outer wheel path.

24. WI-140 Rutting
Southbound outer wheel path on November 4, 2013

25. Axle Load Spectra (Single)
Baseline Traffic
Baseline Traffic with OSOW Permits Included

26. Axle Load Spectra (Tandem)
Baseline Traffic
Baseline Traffic with OSOW Permits Included

27. Axle Load Spectra (Tridem)
Baseline Traffic
Baseline Traffic with OSOW Permits Included

28. Axle Load Spectra (Quad)
Baseline Traffic
Baseline Traffic with OSOW Permits Included

29. International Roughness Index (IRI)
Threshold: 200 in/mi
Final IRI at 20 years using only WisDOT standards occurs after 18 years of service using ALS with permits integrated and 6 hour traffic count for VCD.

30. Rutting
Threshold: 0.5 in
Final rutting at 20 years using only WisDOT standards occurs after 14 years of service using ALS with permits integrated and 6 hour traffic count for VCD.

31. Fatigue Cracking Threshold: 20%
Final fatigue cracking percent at 20 years using only WisDOT standards occurs after 15 years of service using ALS with permits integrated and 6 hour traffic count for VCD.

32. Analysis of Results
WisDOT standards for AASHTOWare of pavement design does not take OW trucks into consideration.
VCD and ALS traffic data could lead to most accurate results.
Final stresses of pavement occurring after 20 years of service showed up years earlier using VCD of WI-140 along with OW traffic integrated into ALS.

33. Future Research
Locate roadways with heavy truck traffic and analyze pavement in Illinois, Iowa, and Minnesota conducting field surveys.

34. Summary
Certain state highways with high OW traffic (and high regular truck traffic) have serious pavement problems, such as WI-140.
Future research will utilize MEPDG to explore effects of OW and SHL trucks on pavement.

35. Acknowledgements CFIRE for the financial support of this project.
WisDOT for providing permit data (Kathleen Nichols, Lynn Judd, and Ed Lalor)
IADOT for providing permit data (Paul Trombino III, Phou Baccam, and Randal Anderson)

36. Questions? Contact: Dr. Hani Titi, titi@uwm.edu
Valbon Latifi,
Nicholas Coley,