Directional Acoustic Vehicle Alerting Systems: A Review of the Literature and Simulation Model for a Shared Zone Closed Car Park

The widespread adoption of electric vehicles presents an opportunity to reduce the contribution of road traffic to noise pollution. However, concerns have been raised about the increased danger that quieter vehicles pose to other road users, as they may be less detectable. To address these concerns, Acoustic Vehicle Alerting Systems (AVAS) are currently legally mandatory in many parts of the U.S. and Europe. However, the addition of noise from AVAS has sparked controversy regarding missed opportunities for a quieter environment. To mitigate this, various researchers have developed and evaluated concepts for a directional sound source to be used in AVAS, which could address the issue of detectability while minimizing noise pollution. This work reviews the existing literature on vehicle directional alerting concepts and evaluate their effectiveness in the particularly concerning case of a shared zone closed car park, using an acoustic simulation model. Sound levels are measured for scenarios with directional AVAS and conventional AVAS (non-directional).