Effects of Auditory Display Types and Acoustic Variables on Subjective Driver Assessment in a Rail Crossing Context

Abstract

Highway-rail grade crossings (HRGCs) present multiple collision risks for motorists, suggesting the need for additional countermeasures to increase driver compliance. The use of in-vehicle auditory alerts (IVAAs) at HRGCs has been increasing, but there are limited standards or guidelines on how such alerts should be implemented. In the current study, we sought to investigate the effect of different auditory display variables, such as display type and acoustics, on subjective user assessments. We recruited 24 participants and asked them to rate 36 different IVAAs belonging to one of three display types (earcons—short synthetic tones, speech alerts, and hybrid alerts consisting of an earcon and speech) along 11 subjective ratings. Results showed that a hybrid alert led to better overall ratings for acceptance, safety, and semantic understanding when compared with earcon or speech alerts. Additional analyses revealed that semantic variables, such as speech order and gender, should be accounted for when designing IVAAs in an HRGC context. Hybrid IVAAs with spatial audio showed lower Urgency and Hazard level ratings. Findings of the current study can help inform the design of IVAAs for HRGCs.

Preliminary Evaluation of Lead Time Variation for Rail Crossing In-Vehicle Alerts

“…The RCVW system warns drivers if they do not seem to take appropriate actions near the crossing, if the crossing they stopped at is currently active, and the likely presence of trains around. Finally, our research group has also conducted a systemic design of auditory alerts for HRGCs [6,7], showing that hybrid auditory alerts using both speech and non-speech components are preferred for the rail crossing situation.…”

“…IVAAs have been successfully used for rear and forward collision warnings [1,2], intersections [3,4], and take-over alerts in automated vehicles [5]. In the field of rail crossings, IVAAs have been suggested as a method to control and reduce the incidence of Highway-Rail Grade Crossing (HRGC) accidents [6,7]. As these locations present increased risk to drivers due to the lethality of accidents [8] and the incidence of inattentive driving [9], IVAAs present many benefits in increasing safety and alerting drivers on-time for responding to the crossing [10].…”