4.3 Required Information and Supporting Documentation

The following table lists the required information and documentation that must be included in the request for changing load limits on county roads and bridges.
Table 13-4: Required Information and Supporting Documentation
Roads
Bridges
  • A cover letter that includes:
    • Name, phone number, email address for a county contact person.
    • Route name/number, location including limits of proposed load zoning, and length (in feet) of the section to be load zoned.
    • Reason for the proposed change.
    • The current and proposed limits. The Gross Vehicle Weight (GVW) and allowable axle weights should be specified.
    • Date of the last rehabilitation or reconstruction performed on the road.
  • Description of pavement typical sections and section limits, including layer thickness, material types, lane and shoulder widths, and curb and gutter locations, if applicable.
  • Engineering Analysis - Supporting documentation that has been sealed by a professional engineer. The engineering analysis shall follow one of the methods described below.
  • Name, phone number, email address for a county contact person.
  • Route name/number, location, feature crossed, and structure number (if known).
  • Reason for the proposed change.
  • Supporting documentation that has been sealed by a professional engineer and includes a structural evaluation report documenting the condition of the bridge and calculations supporting the proposed limits. Calculations should include the inventory and operating ratings for the bridge as defined by the AASHTO
    Manual for Condition Evaluation of Bridges
    , Chapter 6.
Engineering Analysis
An engineering analysis is required for load posting roadways. The analysis and recommendations are required to be signed and sealed by a professional engineer. The analysis must demonstrate that the recommended gross vehicle weight or limiting axle load group is expected to preserve the pavement structure. TxDOT recommends a remaining life of approximately 10 years; however, the analysis may result in less when accompanied by supporting justification.
At a minimum, an engineering analysis must include the following information and analysis supporting the load zoning recommendation:
  • Location map
  • Pavement visual distress and condition evaluation
    • Extent (location and severity)
    • Distress analysis (identification and causes)
  • Traffic load study data supporting a 10-year analysis including:
    • Average Annual Daily Traffic
    • Percent Trucks
    • Equivalent Single Axle Loads
  • Characterization of pavement layers
    • Manual field tests using the dynamic cone penetrometer or similar device;
    • Laboratory test results;
    • Deflection analysis based on the falling weight deflectometer or similar device;
      or
    • Other test methods appropriate for pavement analyses.
  • Analysis of pavement structure and proposed load limit determination using one or more of the following methods:
    • Mechanistic analyses (determination of maximum allowable load using stress and strain calculations)
    • Analyses of deflection data using a Falling Weight Deflectometer or other similar measurement equipment
    • The Texas triaxial method by classification of soil presented in “Determining Allowable Pavement Load Limit Using the Texas Triaxial Classification Procedure” at .
    • Other appropriate analytical methods based on accepted engineering practice