Alerting Lights on Locomotives: Research Results

011569222007PDFTech ReportRR07-17Human factorsLocomotivesRailroad grade crossingsSignal lightsVisibilityTechnology assessmentRailroad safetyRailroadsSafety and Human FactorsVehicles and EquipmentI91: Vehicle Design and SafetyUnited StatesUnited States. Federal Railroad AdministrationRaslear, ThomasUnited States. Federal Railroad AdministrationUS Transportation CollectionIn 1991, the Federal Railroad Administration (FRA) Office of Research and Development initiated a locomotive conspicuity research program with the Volpe Center, to evaluate experimental locomotive alerting light devices and patterns. The FRA Office of Safety used the results in its rulemaking activity, initiated in response to a 1992 congressional mandate to issue interim regulations to improve conspicuity of locomotives to motorists. Preliminary results of the program were considered by FRA in issuing of two interim rules in 1993 and 1994. Upon conclusion of the program in 1995, the research results served as the basis for the final rule issued in 1996 and amended in 2003 and 2004. The study consisted of two components: (1) technology assessment and (2) human perception and recognition. The technology assessment addressed the luminous intensity, flash rate, cost of auxiliary lighting components, and the potential for a selected auxiliary lighting system to reduce the number of accidents at highway-rail grade crossings. It consisted of literature reviews, laboratory tests, and 3 years of in-service testing of a triangular alerting pattern using active warning crossing lights in combination with standard headlights. The human perception and recognition research consisted of controlled field tests to evaluate the ability of three auxiliary lighting systems to enable motorists to recognize the locomotive as a potential hazard and estimate its arrival at a grade crossing. Each system consisted of a pair of auxiliary lights (crossing lights, ditch lights, or roof-mounted strobe lights) that formed a triangle with the headlights. All three alerting light systems evaluated in the human perception and recognition tests were found to be more effective as warning devices than standard headlights alone. FRA regulations now require use of one of those systems. The crossing light system provided the greatest advance warning of train arrival at the grade crossing during the human perception and recognition tests. Data from the technology assessment indicated a potential for significant accident rate reduction with use of the crossing light system.78