Abstract

Vehicles that are backing up represent a workplace hazard, even if they are equipped with backup alarms. Over the past 15 years at least 22 fatal accidents on Québec construction sites have involved vehicles backing up. This research project was undertaken to identify the optimum acoustical properties of backup alarms and their optimum location on vehicles. The first phase of the research consisted of the identification and characterisation of existing alarms, patents, standards and regulations, and of vehicles involved in this type of accident. In the research’s second phase, the limitations of current alarms were identified. The third phase, reported here, focussed on the development of a backup-alarm simulator. Using this simulator, it was found that the most audible alarm signal is a pulsed three-tone (1 000, 1 150, and 1 300 Hz) signal of less than 100 dB(A). Optimal alarm locations were also identified for various vehicles.