American Society of Civil Engineers

Impact of Systematic Axle Load Measurement Error on Pavement Design Using Mechanistic-Empirical Pavement Design Guide

by Syed Waqar Haider, (corresponding author), (Assistant Professor, Dept. of Civil and Environmental Engineering, Michigan State Univ., East Lansing, MI. E-mail:, Ronald S. Harichandran, (Professor and Chairperson, Dept. of Civil and Environmental Engineering, Michigan State Univ., East Lansing, MI. E-mail:, and Monther B. Dwaikat, (Assistant Professor, Dept. of Building Engineering, An-Najah National Univ., Nablus, West Bank, Palestine. E-mail:

Journal of Transportation Engineering, Vol. 138, No. 3, March 2012, pp. 381-386, (doi:

     Access full text
     Purchase Subscription
     Permissions for Reuse  

Document type: Technical Note
Abstract: In traffic characterization, axle load spectra (ALS) are one of the most critical inputs in the new Mechanistic-Empirical Pavement Design Guide (MEPDG). Axle load spectra have a significant effect on predicted pavement performance and, thus, the design life. Typically, axle load spectra as measured by weigh-in-motion (WIM) systems are assumed to have adequate data quality and accuracy. In fact, the quality of WIM-based data has inherent uncertainties attributable to inaccuracy and systematic bias. Whereas WIM data accuracy depends on the sensor technology, calibration errors and drift over time may introduce a systematic bias. This technical note investigates the effect of axle load measurement bias on pavement design for flexible and rigid pavements. The results show that negative bias in axle load measurements significantly affects cracking performance for both pavement types. The bias is more critical for rigid pavements with thinner slabs. Therefore, a measurement bias limit of less than ±5% should be required to ensure that both flexible and rigid pavements have adequate design reliability against cracking. That the WIM scales be calibrated periodically to prevent a high negative bias is strongly recommended.

ASCE Subject Headings:
Traffic management

Author Keywords:
Axle load spectra
Random errors
Pavement design