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Title:I-80 Hybrid Regulatory Speed Limit Signing Design and VSL System Evaluation
Authors:Bahar Azin and Xianfeng "Terry" Yang
University:University of Utah
Publication Date:Sep 2022
Report #:MPC-22-488
Project #:MPC-610
TRID #:01869381
Keywords:color, highway safety, traffic signs, variable speed limits, visibility



performance in the presence of variable road hazards. Road networks plagued by consistent weather or work zones affecting driving conditions are where VSL systems could improve safety. Depending on the road condition and objective of the VSL installation, the system could be advisory or regulatory. In a segment of the I-80 freeway in Parley's Canyon, Utah, due to elevation variation and snowstorms in winter, a variable speed zone is deployed on a segment of the road. Meanwhile, due to harsh weather in the road segment, signs designed with a white legend on a black background have shown to have limited visibility in these environments. Therefore, the Utah Department of Transportation (UDOT) has substituted the sign with an amber legend for improved visibility. This study tries to evaluate the effectiveness of new signs on corridor safety and compare road efficiency with both signs. The analysis is done using field trip recordings, recorded data of various sensors in this corridor, and crash data. Also, a safety evaluation model is developed to assess the traffic operation functionality and safety in response to the VSL system's automation and visibility of the new signs on the road. Driver compliance rate and road safety outcomes by the models determine the impacts of the new system on road safety.

How to Cite

Azin, Bahar, and Xianfeng "Terry" Yang. I-80 Hybrid Regulatory Speed Limit Signing Design and VSL System Evaluation, MPC-22-488. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2022.

NDSU Dept 2880P.O. Box 6050Fargo, ND 58108-6050