Variable Speed Limits Could Reduce Crashes, Ease Congestion in Highway Work Zones

Typography

As the summer months approach, most people turn to thoughts of sunshine, outdoor barbecues and destination trips. Yet travelers often are greeted by detours, lane closures and delays for road repairs that generally are reserved for warmer weather. Researchers at the University of Missouri have studied systems to alleviate inevitable backups and delays. Researchers found that using variable speed limits in construction zones may ease congestion, reduce crashes and make work zones safer for both workers and travelers nationally.

With assistance from the Missouri Department of Transportation, Praveen Edara, associate professor of civil and environmental engineering in the MU College of Engineering, tested the use of variable advisory speed limit (VASL) systems and the effect they may have on lessening congestion and reducing rear-end and lane-changing accidents on a fairly dangerous stretch of I-270, a major four-lane highway in St. Louis.

As the summer months approach, most people turn to thoughts of sunshine, outdoor barbecues and destination trips. Yet travelers often are greeted by detours, lane closures and delays for road repairs that generally are reserved for warmer weather. Researchers at the University of Missouri have studied systems to alleviate inevitable backups and delays. Researchers found that using variable speed limits in construction zones may ease congestion, reduce crashes and make work zones safer for both workers and travelers nationally.

With assistance from the Missouri Department of Transportation, Praveen Edara, associate professor of civil and environmental engineering in the MU College of Engineering, tested the use of variable advisory speed limit (VASL) systems and the effect they may have on lessening congestion and reducing rear-end and lane-changing accidents on a fairly dangerous stretch of I-270, a major four-lane highway in St. Louis.

“The idea was to see if warning drivers of slower speeds ahead helped reduce crashes,” Edara said. “Where there is queueing, if drivers are not aware of the queue downstream, they don’t have enough time to hit the brakes to slow down or stop, thus, increasing the likelihood of a crash. Instead of posting a message asking them to slow down, the VASL system posts an advisory speed limit based on the actual downstream traffic speed, so drivers would know that if they’re driving 50 mph, they should slow to 30 mph downstream.”

Continue reading at University of Missouri-Columbia

Image via publicdomainpictures.net