Development of Simplified Factors for Lateral Distribution of Loads of Non-Standard Gauge (NSG) Axles

The Ohio Department of Transportation (ODOT) processes upwards of 335,000 oversized permits annually using the Ohio Hauling Permit System (OHPS). OHPS is an automated permit processing system developed by Promiles, Inc. The OHPS uses the AASHTO Bridge Rating (BrR) system and the AASHTO Rating Tool (RT) to analyze bridges for permit loads. The RT in OHPS assumes all axles have standard gauge (i.e., 6 ft. between tires, weight not exceeding 80,000 lbs.). While a significant amount of the permit applications received falls within the parameters of a standard gauge load, approximately 215,000 applications annually do not. When non-standard gauge (NSG) axle loads are run through OHPS, they generally produce inaccurate results and often fail. Therefore, NSG axle loads applications require rigorous and time-consuming analysis that must be performed manually by ODOT structural engineers. Depending on the proposed route, a single permit application for an NGS axle load can include analysis of up to 180 bridges. In an effort to streamline the analysis of NSG axle loads, ODOT engineers developed a conservative correction modifier of 0.6 that is applied in the AASHTO analysis. Based on experience and engineering judgement, the weight of each axle is multiplied by the correction modifier in an attempt to simulate the use of multiple lanes depending on the width of the axle. The result is a single dimension being used for all NSG axle loads, which is not necessarily accurate. As a result, loads could be disallowed on bridges that are capable of supporting the load and unnecessarily rerouted. The goal of this research is to improve ODOT's processes for analyzing NSG axle load permits. This research will identify a more accurate correction modifier or set of modifiers to use during the NSG axle load analysis. Refined modification factors will provide enhanced confidence in the ability of various structures to safely carry specific NGS axle loads. Incorporating the findings of this research into the OHPS will allow ODOT to be more efficient and accurate in the permitting process.


  • English


  • Status: Completed
  • Funding: $90328
  • Contract Numbers:




  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Managing Organizations:

    Ohio Department of Transportation

    Research Program
    1980 West Broad Street
    Columbus, OH  United States  43223
  • Project Managers:

    Fout, Vicky

  • Performing Organizations:

    Burgess & Niple, Inc.

    5085 Reed Rd.
    Columbus, OH  United States  43220
  • Principal Investigators:

    Butz, Travis

  • Start Date: 20210901
  • Expected Completion Date: 20220701
  • Actual Completion Date: 20220701

Subject/Index Terms

Filing Info

  • Accession Number: 01780662
  • Record Type: Research project
  • Source Agency: Ohio Department of Transportation
  • Contract Numbers: 36495, 114241, 136336
  • Files: RIP, STATEDOT
  • Created Date: Aug 30 2021 1:18PM