Evaluation of Wisconsin Bridges for Truck Loads

Quarterly Reports Other Documents Final Report
December 2009  Final Report

Primary Investigator

Mike Oliva
University of Wisconsin – Madison
1415 Engineering Drive, 1214 EH
Madison, WI 53706


The State DOT recently examined load limits for highway bridges in Wisconsin to allow heavier trucks, particular if truckers had additional axles attached to their trucks to spread loads. Most of the companies involved in transporting timber in northern Wisconsin added the required extra axle at substantial cost. Though the truckers added the extra axles, many of counties still placed load restrictions on the essential bridges on local roads. The State is now in the final stages of completing a second study on truck size and weight limits for Wisconsin. This project will focus on developing guidelines to aid county officials in deciding whether load ratings are needed and investigate the impact of load ratings and possible new truck configurations on local road bridges. Removal of non-essential load ratings will save the Wisconsin trucking industry many thousands of dollars, particularly with high fuel prices, and reduce truck emissions by shortening haul routes.


The overall objective of ongoing work is to develop guidelines for decision makers in evaluating whether highway bridges need to have truck load limits and what limits are appropriate.

The immediate objective of the work proposed to CFIRE is to evaluate the impact that existing regulations and possible new size and weight limits will have on freight transportation, particularly in the timber industry, over local and state trunk roads in Wisconsin.


  1. Conduct a complete survey of bridges in selected counties
  2. Categorize bridges in the selected counties by their current load ratings
  3. Categorize bridges in selected counties by their current postings
  4. Analyze a series of bridges for the effects of the new proposed size and weight limits
  5. Statistically predict what the impact of the new truck size and weight limits will be on posting of bridges in the selected counties
  6. Work with counties and the timber industry to develop a better understanding of the need for bridge postings and the impact of postings on industry and the local economy

Project Information

  • Duration: 9 months
  • Dates: January 1, 2009 – August 31, 2009
  • Budget: $36,976
  • Student Involvement: One undergraduate
  • Modal Orientation: Highway
  • Project ID: CFIRE 03-05
Print Friendly