Stephanie Chase

Effect of Dynamic Envelope Pavement Markings on Vehicle Driver Behavior at a Highway-Rail Grade Crossing

The United States Department of Transportation’s (USDOT) John A. Volpe National Transportation Systems Center (Volpe Center), under the direction of the USDOT Federal Railroad Administration (FRA) Office of Research and Development (R&D), recently completed a study on the use of pavement markings to reduce instances of vehicles stopping on the tracks at grade crossings. Specifically, the study evaluated the effectiveness of pavement markings placed within the dynamic envelope, the region between and immediately adjacent to the tracks at a grade crossing, and new corresponding signage at the Commercial Boulevard grade crossing (ID# 628186E) in Ft. Lauderdale, Florida. The goal of this research study was to gain an understanding of the effect of dynamic envelope pavement markings and accompanying signage on driver’s not stopping while traversing the tracks. The addition of the dynamic envelope markings and signage is intended to make this area more pronounced, resulting in fewer motorists entering the dynamic envelope if they are unable to exit the other side.Researchers coded driver stopping behavior at this crossing before and after the surface treatments were installed. Vehicles were coded as having stopped in one of four zones: behind the stop line and gate arm (Zone 1), past the stop line but before the tracks (Zone 2), on the tracks (Zone 3), or immediately after the tracks (Zone 4). Stopping in Zone 3 is considered to be the most dangerous behavior that a driver could perform, while stopping in Zone 1 is the safest.The goal of the added markings and signage is to reduce the number of vehicles which come to a stop within the dynamic envelope, thus reducing the possibility that a vehicle is present on the tracks when a train approaches resulting in a collision. The addition of the dynamic envelope pavement markings and modified signage resulted in a statistically significant change in driver stopping behavior. Specifically, the pavement markings and signage reduced the proportion of vehicles that stopped in Zone 3, resulting in a 45% reduction in vehicles stopped in Zone 3 for eastbound vehicles and 14% for westbound vehicles. They also increased the proportion of vehicles stopping in Zone 1, which is the safest behavior a driver can perform (9% increase for eastbound and 6% increase for westbound). Additionally, fewer vehicles were found to stop in both Zone 2 and Zone 4, which are both moderately dangerous.Based on these results, the Florida Department of Transportation is exploring the use of this safety treatment at additional grade crossings with a high risk for unsafe vehicle stopping behavior.