Application of WIM and Permit Data

The objective of this project was to (1) improve the procedures for processing and evaluation of the quality of the weigh-in-motion (WIM) data, (2) develop an analytical procedure to identify legal, permitted and illegal vehicles in the WIM records, (3) develop a set of algorithms to evaluate fatigue damage accumulated in steel bridges and (4) make recommendations regarding which traditional WIM stations is to be converted to Virtual Weigh Stations. Alabama Department of Transportation (ALDOT) collects traffic data including records of millions of vehicles at each of the 12 WIM site every year on a continuous basis. Every day the Maintenance Bureau issues 500 to 600 oversize or overweight permits. Knowledge of the actual loads including illegally overloaded vehicles can help in day-to-day and planned maintenance procedures and law-enforcement efforts. ALDOT provided WIM data from 12 WIM stations for the years 2014 to 2016 and issued permit data by ALDOT for the year 2014 and 2015. It was found from the developed procedures that two of the WIM stations were not functioning properly and the WIM data could not be used. The 20% of trucks that are overloaded create more than 50% of the total damage for the traffic combined from all the locations. 16-18% of trucks that are illegally overloaded create more than 40% of the total damage. Based on the truck traffic recorded at WIM site 931 (Athens), the fatigue life of steel girder bridges along the route is consumed four times faster than expected for a design life of 75 years. For traffic recorded at WIM sites other than 931 (Athens), 942 (Pine Level) and 961 (Mobile), the fatigue life of steel girder bridges is consumed slower than expected for a design life of 75 years. Two computer apps were developed for implementation by ALDOT of the developed procedures. The computer app, ALDOT_WIM_QC v1.0, can be used to evaluate the quality of the WIM data and maintain the “health” of WIM systems. Another application, ALDOT_WIM_DAI v1.0, can be used to evaluate the fatigue damage in a steel girder bridge due to the traffic recorded at the WIM site. The results of the fatigue damage calculations can be used to evaluate the significance of the truck traffic along various routes and the impact of the various Federal Highway Administration (FHWA) Vehicle Classes on the total damage.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 171p

Subject/Index Terms

Filing Info

  • Accession Number: 01712410
  • Record Type: Publication
  • Report/Paper Numbers: ALDOT 930-947
  • Created Date: Jul 10 2019 12:20PM