Evaluation of Traffic Input Levels for Pavement Me Design

Abstract

Traffic loads are one of the key data elements required for the design and analysis of pavement structures. The MEPDG requires full axle-load spectrum mainly based on continuous site-specific Weigh-In-Motion (WIM) data sets for each axle type and axle-load group. Due to the fact that collecting high quality WIM data is expensive, challenging and analyzing them requires extensive efforts and expertise, many state DOTs have to rely on traffic data from various acquisition technologies and length of time coverage for the implementation of MEPDG. This paper studies the impacts and variability of various traffic data collection efforts on MEPDG predicted performance. Twelve traffic data input scenarios are simulated to consider various traffic data collection efforts at 20 WIM sites in Oklahoma. A total of 1,440 MEPDG runs are performed with 3 AADTT levels, and 2 growth rates. The impacts of traffic load level, WIM data coverage, vehicle distribution, axle loading, and using regional and national defaults on predicted pavement performance are evaluated. This study has recommended the minimum required traffic data collection efforts for highway agencies to prepare traffic data for the implementation of MEPDG.