Railroad Horn Systems: Research Results

Federal Railroad Administration2007PDFBriefRaslear, ThomasUnited States. Department of Transportation. Federal Railroad AdministrationUnited States. Department of Transportation. Federal Railroad AdministrationUnited StatesRailroad grade crossingsRailroad safetyRailroad trainsAudible warning devicesHornsNoise controlWarning signalsCrash ratesFatalitiesInjuriesRR07-06From 1992 to 2002, the Federal Railroad Administration (FRA) Office of Research and Development (ORD) sponsored a multi-dimensional study of horns as warning devices, conducted by the Volpe Center. The purpose of the study was to assess ways to provide adequate warning. The results were used as the basis for a final rule, established in June of 2005, for sounding audible warnings before a train arrives at a grade crossing. The study consisted of two components: (1) technology assessment and (2) human perception and recognition. The technology assessment addressed physical characteristics. It consisted of (1) measurement of the acoustic properties of three typical railroad horns and prototype automated horn systems (AHS), (2) measurement of the insertion loss and interior noise levels of several 1990 and 1991 motor vehicles, (3) laboratory studies to assess the effectiveness and detectability of horn signals, and (4) measurement of horn sound levels at multiple measurement locations. The human perception and recognition research addressed the effectiveness of those systems as warning devices and their impact on the daily activities of residents. It consisted of (1) use of video cameras at selected grade crossings to observe driver behavior after sounding of three-chime train horns and AHS mounted on the wayside and (2) surveys of residents along railroad corridors about the effects of those two horn systems on their daily activities.140