Variable Speed Limits System for Elk Mountain Corridor: FHWA-WY-10/04F
Determining an appropriate speed for the current conditions can be difficult for the driver. Equally difficult is for law enforcement agencies to enforce and cite someone going too fast for conditions. In many cases, drivers are cited for going too fast for conditions only after the accident has occurred. Variable speed limits (VSL) are one type of intelligent transportation system (ITS) that has shown promise for improving safety on roadways subject to adverse conditions. The purpose of this research was to lay the foundation for the new I-80 VSL system in southeastern Wyoming. During this phase of the research, surveys were sent out to all DOTs to see what VSLs have been implemented in the U.S. Driver speed behaviors during both “ideal” and “non-ideal” conditions were found and baseline speeds determined. Weather and speed data were analyzed to determine key variables and threshold values. To check how cars and trucks are reacting to the VSL system individual speed analysis was done. A draft version of control strategy was designed and a simulation was run to check for level of speed compliance. The final task was to determine how drivers are reacting to the new VSL system.