An evaluation of modifications to the advance warning sign at passive highway-railroad grade crossings

Abstract

With the passage of the North American Free Trade Agreement Act, there is quite a potential for an increase in rail traffic in the state of Texas. Despite the fact that the number of vehicle-train collisions that occurred decreased 47 percent between 1981 and 1992, safety at highway-railroad grade crossings is still a major concern. This thesis investigates modifications to the existing advance warning sign used at highway-railroad grade crossings. A literature review was conducted to find supporting information that explains the importance of this research relative to other research being conducted in the area of railroad grade crossing safety. The background and supporting information includes information on highway-railroad grade crossings, driver behavior at highway-railroad grade crossings, and effectiveness of traffic control devices that have supplemented the standard signing system with strobe lights. The objective of this research was to determine if the addition of a strobe light to an advance warning preceding a passive railroad crossing would result in adverse driver reactions such as slamming on the brakes or erratic steering maneuvers. Approaching motor vehicles detected by a motion sensor activate a strobe light which flashed until the vehicle passed the advance warning sign. The modified sign system was tested at a closed driving course at the Texas A&M University Riverside Campus. In addition to the driving test, study participants completed a questionnaire and participated in a group discussion to determine their opinions of the three signs they saw on the driving course: the standard advance warning sign, the advance warning sign modified with a standard flasher and an the advance warning sign modified with a vehicle activated strobe light. None of the three signs, including the strobe modified sign, resulted in any adverse driver reactions. The strobe light and flasher modified signs did, however, solicit more braking than did the standard sign. Head movement at each of the three signs was not found to be statistically different. Participants clearly preferred the standard flasher modification to the strobe light. Furthermore, the strobe light sign was preferred over the standard sign. Both the strobe fight and the standard flasher were said to have better attention gaining qualities than the standard sign that made drivers exercise greater caution near them. While some drivers simply did not like the strobe light, only three subjects said it startled them. Most of the startling that they experienced was attributed to the novelty of the strobe and the fact that they were trying to determine what was flashing with such an irregular pattern.