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Title:Automating the Implementation of the Updated Grade Severity Rating System (GSRS) for Wyoming Mountain Passes
Authors:Vincent-Michael K. Ampadu, Muhammad Tahmidul Haq, and Khaled Ksaibati
University:University of Wyoming
Publication Date:Mar 2023
Report #:MPC-23-496
Project #:MPC-540
TRID #:01879154
Keywords:brakes, downgrades (roads), highway curves, mountain roads, ratings, software, trucking safety
Type:Research Report – MPC Publications


Truck crashes on steep downgrades caused by excessive brake heating is an ongoing concern for the Wyoming Department of Transportation (WYDOT). Crashes resulting from brake failure on downgrades cause a devastating toll on lives and property. To counter such crashes, WYDOT initiated a research project in 2016 to update a previous Grade Severity Rating System (GSRS) model originally developed in 1981. This was necessary due to the previous GSRS model being considered insufficiently representative of current truck characteristics, which have undergone significant changes over the decades. This study sought to fulfill Phase II of the GSRS study and was aimed at achieving three objectives. The first objective was to validate the GSRS model for trucks that have only drum brakes installed. The second objective was to make the updated GSRS fully implementable by incorporating horizontal curves into the formulation of the weight-specific speed (WSS) signs. The final objective was to develop a software that simplifies the implementation of the GSRS and the formulation of WSS signs by generating maximum descent speeds for different weight categories as output.

How to Cite

Ampadu, Vincent-Michael K., Muhammad Tahmidul Haq, and Khaled Ksaibati. Automating the Implementation of the Updated Grade Severity Rating System (GSRS) for Wyoming Mountain Passes, MPC-23-496. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2023.

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