Last week, the speed limit returned to 75 mph on a 52-mile section of Interstate 80 in Wyoming between Rawlins and Laramie, where a seasonal limit of 65 mph had been in force since Oct. 15.
The seasonal limit was imposed because the highway section is prone to unpredictable and extreme weather that changes quickly, the Wyoming Department of Transportation said. The goal of the lower limit was to reduce crashes and highway closures by giving drivers more time to react to rapidly changing conditions.
WYDOT implemented the seasonal limit for the first time in 2008, and is compiling crash and closure data to assess the effectiveness of the reduced limit and variable speed limit signs installed on the I-80 section.
The University of Wyoming is conducting a 30-month study to help determine the effectiveness of the variable speed limit system, WYDOT said. The study includes analysis of weather sensor data and other factors that can be used to develop a decision support system for setting the appropriate speed for conditions.
Data gathered will help decide whether to continue implementing the seasonal speed limit in the future and whether to install variable speed limit signs on other highway sections in the state, WYDOT said.