Variable Speed Limits
The Virginia Department of Transportation (VDOT) will install variable speed limits (VSL) to enhance safety in the I-95 North corridor between mile markers 115 and 130 in Caroline and Spotsylvania counties, and the City of Fredericksburg.
Crashes have occurred when northbound vehicles traveling at speed unexpectedly encounter stopped or slowing traffic flow due to congestion or lane closures for incidents and highway work zones.
New signs displaying variable speed limits between 35 mph and 65-70 mph will be paired with dynamic message boards in this section of I-95 North. Drivers will adjust their speed based on real-time information about delays and conditions on the road ahead. Gradually slowing traffic as it approaches congestion will help to reduce the risk of crashes, and stop-and-go travel conditions.
Speed limits will be reduced only when necessary. Speed limits posted on VSL are enforceable just like regular speed limit signs. Enforcement authorities will have access to real-time changes in posted speed limits along the VSL corridor.
of Variable speed limits:
- Seeks to reduce crashes
- Increases vehicle throughput
- Fewer stop-and-go conditions
- Informs travelers of conditions on the road ahead
Vehicle detectors will collect traffic speed and volume data, which will be fed into a software program to recognize when traffic is approaching unstable conditions (for example, very high volume and fast speed) and assign incrementally lower speeds. Once traffic flow stabilizes, the posted speed limit will return to the maximum speed. Speeds can also be lowered manually by operators at VDOT’s Traffic Operations Center to create safer conditions in work zones, in weather events, and around traffic crashes.
Variable speed limits were recommended for this section of I-95 North as part of the I-95 Corridor Improvement Plan. Based on the expected success of this deployment, VDOT anticipates the implementation of VSL at additional locations throughout the Commonwealth.
Learn more:• Commonwealth Transportation Board presentation
• Frequently Asked Questions (FAQ)