Control strategy for rural variable speed limit corridor

Speed and speed variance of vehicles are important factors related to safety, especially during severe weather conditions. A variable speed limit system was implemented in 2009 by the Wyoming Department of Transportation to change the posted, enforceable speed limits in an effort to improve safety. During the initial years of implementation, decisions regarding the posted speed limit were made by maintenance, highway patrol, and traffic management center personnel. This paper discusses the development of a methodology to support speed posting decisions based on the real-time observed vehicle speeds and weather variables. The results from simulations performed with the proposed methodology indicate that there could be a significant increase in speed compliance and reduced speed variation with the implementation of an automated control strategy over the current manual protocol.