Oversize/Overweight Permit Harmonization

Part of our national framework for size and weight enforcement is the concept that states have control of the processes for issuing permits for vehicles traveling over “legal” size and weight limits. States set limits, with some guidance from the Federal government for certain types of highways, about dimension (height, length, width), and weight (gross and/or per-axle). In addition, states set guidelines on the conditions associated with the permitting process, such as allowable times of operations, warning devices, and escorts. The American Association of State Highway Transportation Officials’ (AASHTO) Subcommittee on Highway Transport (SCOHT), which was the predecessor to the CTSO Working Group on Freight Operations, has been involved in the issue of harmonization of state truck permitting requirements for many years.

Harmonization is not the same as uniformity. Harmonization establishes baseline restrictive thresholds for various characteristics of an issued permit, but allows and encourages each state to find the appropriate, less restrictive, measures that will serve both the citizens of their state as well as the motor carrier industry. Establishing a harmonized baseline enables interstate carriers the opportunity to standardize their multi-state transport processes, while allowing each state to still innovate and allowing carriers to leverage those innovations when practical and prudent.

Reports about the harmonization about state truck permitting, spreadsheets tracking the states’ adoption of harmonization thresholds, and other supporting documents are available on this page.

Guide for Maximum Dimensions and Weights of Motor Vehicles, 5th Edition, Single User PDF Download

This guide provides information for states and commercial carriers that can be used in connection with vehicle size and weight issues and permit practices directed towards improving safety, managing highway and bridge infrastructure, and streamlining regulatory processes. It contains definitions of commonly-used terms, descriptions of vehicles in regular operation, dimension and weight limits, and an overview of the permitting process for overweight, oversize vehicles. It also provides an explanation of the rules and processes related to the movement of military vehicles.

Additional Harmonization Materials: