Evaluation of enhanced traffic control devices for use at highway-railroad grade crossings

Abstract

A frequently cited factor in highway-railroad grade crossing accidents is driver error. Driver error may result from the failure to perceive a train at or near the crossing. Alternatively, drivers may detect train but fail to accurately determine the time available to clear the crossing. Violation of driver expectancy has been cited as a leading cause of faulty decision making. Drivers who rarely encounter trains at familiar grade crossings may expect the same at unfamiliar crossings with higher train volumes. The majority of grade crossings will continue to have only signs and markings that provide passive warning to drivers because it is not economically feasible to provide active control at each grade crossing. Thus, enhanced traffic control devices are needed at passive grade crossings to increase driver awareness. The objective of this research was to evaluate the effectiveness of two experimental traffic control devices at highway-railroad grade crossings. The first experimental sign system consisted of a 36 inch YIELD sign with a supplemental message plate containing the phrase TO TRAINS. The second experimental sign consisted of a vehicle-activated strobe mounted above a standard railroad advance warning sign. The sign also had a yellow supplemental message sign that read LOOK FOR TRAIN AT CROSSING. To be successful, the enhanced sign systems should increase driver awareness and if necessary, result in more cautious behavior when approaching the grade crossing. Before and after speed profile data was collected at six locations throughout the state of Texas at which the experimental YIELD TO TRAINS and LOOK FOR TRAIN AT CROSSING sign systems were installed. A statistical analysis comparing the before and after speeds at each study site was completed using a two-sample t-test to determine the significance of any speed differences. The results of this research indicate that both the YIELD TO TRAINS and LOOK FOR TRAIN AT CROSSING sign systems had no statistically significant effect on approach mean speed. However, the results also indicated that both enhanced sign systems had no adverse effect on driver behavior.