Evaluation of Auxiliary Signing for Driveway Assistance Devices at Low-Volume Access Points within One-Lane, Bidirectional Work Zones

Abstract

Work zone traffic control presents unique challenges during single-lane closures on two-lane, two-way facilities. In these circumstances, traffic regulators (i.e., flaggers or temporary signals) ensure alternating one-way travel in the work zone. However, the use of traffic regulators becomes less practical at mid-segment low-volume access points, such as driveways and minor intersections, within the lane closure. These locations present additional risk for flaggers and, owing to financial infeasibility, are often rendered without traffic control. A recently developed experimental traffic control treatment, the driveway assistance device (DAD), is designed to provide guidance to motorists for a safe entrance into the lane closure from low-volume access points. As this device is relatively new, much is still unknown about the optimal device design and operation to provide the highest compliance. To address this, a field study was performed to evaluate driver compliance associated with DADs implemented at a series of driveways along a one-lane, two-way work zone along a state highway in northern Michigan. As little guidance exists for DAD auxiliary signage, the field study specifically sought to compare the effects of five different sign messages utilized with the DAD. The driver compliance data revealed that the most effective sign messages were those that included “Turn” instead of “Yield,” a prominent “WAIT” message at the top, in addition to a supplemental “No Turn on Red” sign. Based on these findings, DADs are recommended for continued experimental use along with appropriate auxiliary signage at work zones where one-lane, two-way traffic is being maintained.