An Approach to Designing and Specifying Audibility Requirements of Train Activated Warning Systems

Abstract

Train Activated Warning Systems (TAWS) use an audible warning to alert track-workers of an oncoming train. TAWS emits a safe-tone sound to indicate the system is active. When a train approaches, the safe tone switches to a warning-tone in enough time to allow track workers to reach a position of safety. There is currently no specific methodology for designing a new TAWS system to achieve the required audibility over a defined area of track. This paper presents an approach to the design and specification of TAWS audibility over lengths of track where different prevailing acoustic environment conditions need to be considered. The challenges encountered and the limitations of the resulting approach are discussed.