Driver Comprehension of Driveway Assistance Devices for Work Zones: Evidence from a Nationwide Survey

Driveway assistance devices (DADs) provide traffic control at low-volume access points on one-lane, two-way work zones without the need for flaggers. Interim approval for the optional use of DAD at residential driveways was granted, along with a name change to Residential Driveway Temporary Signal, by the Federal Highway Administration in January 2025. Before this, the DAD was considered an experimental device, with little available guidance toward the configuration and use of the device. This lack of uniform guidance resulted in the implementation of DAD signal arrangements, arrow colors, and auxiliary signage that varied across the United States. Because of the lack of uniformity, much is still unknown about the optimal designs of the signal display and auxiliary signage to provide the highest comprehension and compliance. To address these issues, a nationwide online survey of drivers was conducted to determine the DAD signal configurations and auxiliary sign messages that most effectively communicate the proper action when encountering the DAD. A total of 1,015 responses were received from respondents in 49 states. The survey results suggested that the DAD auxiliary signs most effectively conveyed the proper driver action if the message included the word “Turn” as opposed to “Yield” and if an NTOR sign was included. Furthermore, yellow flashing arrows showed considerably less uncertainty concerning the proper driver action compared with red flashing arrows. Considering the DAD signal head configuration, the horizontal and doghouse configurations more effectively conveyed the proper driver action compared with the red-over-yellow arrows configuration.