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Current News

Title	Impacts of the I-77 Variable Speed Limit System on Speed and Crash Characteristics During Low Visibility Conditions
Date Posted	11/5/2018
URL	http://vtrc.virginiadot.org/PubDetails.aspx?PubNo=19-R6
Description	I-77 in Virginia passes through very mountainous terrain that is prone to severe fog. In October 2016, the Virginia Department of Transportation implemented a variable speed limit (VSL) system on a 12 mile stretch of I-77. The VSL system reduces the speed limit in sections of the highway during a fog event. This study examined the effect of the VSL system on driver's speed and crash rates. The results will be used to refine the VSL control algorithm and act as a reference for other agencies implementing VSL.