Evaluation of Pavement Performance due to Overload Single-Trip Permit Truck Traffic in Wisconsin

Nicholas J Coley,Valbon Latifi,Hani H Titi

doi:10.1155/2018/1070653

Abstract

This study investigated the impacts of overweight (OW) permit truck traffic on flexible pavement performance in Wisconsin using field investigation and analysis utilizing the AASHTOWare Pavement ME Design software. A database of overweight single-trip permit truck records was analysed to produce a network of Wisconsin corridors heavily travelled by OW trucks. Four Wisconsin highways were selected for investigation due to high levels of OW truck traffic. The research included field work (traffic counts and visual pavement surface distress surveys) and AASHTOWare Pavement ME Design. Comprehensive analyses were conducted to evaluate pavement performance due to normal traffic loads as well as normal traffic loads plus the OW truck traffic loads. The use of mechanistic-empirical (ME) pavement analyses provided a methodology for estimating the proportion of pavement deterioration attributable to OW truck traffic. OW axle load distributions were developed and integrated with baseline truck traffic levels to develop axle load spectra and other traffic input parameters for the ME pavement analysis. The predicted total pavement deterioration levels from the AASHTOWare Pavement ME Design software were generally consistent with the levels of deterioration observed. The proportion of pavement damage and deterioration attributable to OW truck traffic was predicted to constitute a relatively minor proportion of total deterioration, with most distress indices showing relative increases of approximately 0.5% to 4%, with a few outliers. However, due to the small proportion of OW vehicles relative to the overall traffic levels, the OW vehicles were generally predicted to cause up to ten times the per-truck damage as compared with a typical legal-weight truck, depending on the distress mode and the test site.

Highlights

With increasing numbers of oversize-overweight (OSOW) vehicle permits issued across the United States as the economy continues to grow, increased scrutiny is being applied to the infrastructure impacts of OSOW vehicles and to the assessment of vehicle size and weight programs from a policy perspective
Because pavement deterioration predictions in the AASHTOWare Pavement ME Design models are dependent on detailed traffic and axle load spectra (ALS) data, determining site-specific ALS variations—especially with regard to the heaviest vehicles—is a crucial step in performing accurate analyses. e objective of this research is to characterize the relative contribution to pavement damage and deterioration induced by single-trip OW permit truck traffic on selected asphalt pavements test sections in Wisconsin. e results of a comprehensive OSOW single-trip permit mapping effort were used to identify state highway segments with high levels of OW truck traffic
Conclusions e results of the ME analyses performed using AASHTOWare Pavement ME Design demonstrated that OW vehicles are likely to have a significantly greater relative contribution to pavement deterioration than typical legal-weight trucks in Wisconsin

Summary

Introduction

With increasing numbers of oversize-overweight (OSOW) vehicle permits issued across the United States as the economy continues to grow, increased scrutiny is being applied to the infrastructure impacts of OSOW vehicles and to the assessment of vehicle size and weight programs from a policy perspective. In the United States, individual states have the authority to issue permits to oversize and overweight (OSOW) vehicles exceeding national and state size and weight limits [1]. In Wisconsin the maximum weight of a group of two or more axles (tandem or greater) is determined based on the spacing between the first and last individual axle within the group Exceptions exist such as higher axle weight limits for vehicles carrying agricultural products or implements, forestry products, or milk products [2]. Motor vehicle operators wishing to operate vehicles exceeding states’ size and weight limits must apply for OSOW permits from each individual state, in accordance with each state’s regulations. Recent years have seen dramatic increases in the number of OSOW permits obtained in various states, including in the number of superheavy vehicle permits, that is, vehicles with a GVW of at least 1,201 kN (270 kips) [3]

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