Characterization of truck traffic in Michigan for the new Mechanistic Empirical Pavement Design Guide

The purpose of this thesis is to characterize truck traffic for the state of Michigan in terms of truck traffic distribution, axle groups per vehicle, axle load distribution factors, monthly distribution factors and hourly distribution factors to facilitate design in the new Mechanistic-Empirical Pavement Design Guide (M-E PDG). Weight and classification data was obtained from 44 Weigh-in-Motion (WIM) and classification stations found throughout the state to develop M-E PDG Level I (site-specific) traffic characteristics. Cluster analyses were then conducted to group sites with similar characteristics together for development of M-E PDG Level II (regional) data. Finally data from all sites were averaged to establish statewide M-E PDG Level III data. A sensitivity analysis using rigid and flexible pavement designs in M-E PDG was then performed for these hierarchical traffic characteristics as well as M-E PDG defaults to determine the necessary data input level to achieve an acceptable level of accuracy in design. Additionally, the effect of length of collection period was also explored by statistically comparing traffic characteristics developed using one week per month data and continuous (year-round) data. Performance differences these traffic characteristics create were analyzed in M-E PDG. For future construction sites in which Level II data is required, a discriminant analyses selection algorithm was created that utilizes the sites' properties to acquire the appropriate Level II traffic characteristic necessary for design.