When a work zone corridor includes driveways or other low-volume roads, accommodating vehicles entering the one-way flow of traffic can be challenging and potentially hazardous for maintenance crews.
Temporary traffic signals have historically been used in these scenarios, but as these devices stop mainline traffic they can add significant travel delays. Another potential option is driveway assistance devices, or DADs, which direct vehicles to join the existing traffic queue.
To evaluate whether DADs are a viable alternative to temporary traffic signals, the Ohio Department of Transportation installed both types of devices at four work zones along State Route 60. Researchers then compared the costs, benefits and effectiveness of both types, as well as a list of recommendations for implementing DADs in the future.
Read the report: Evaluation of Driveway Assistance Devices in Signalized Work Zones, March 2023
Image source: Ohio Department of Transportation