Perceptual and Acoustic Implications of Electric Powered Two-wheelers in Urban Environment

Abstract

The increasing adoption of electric Powered Two-Wheelers (e-scooters and e-motorcycles) in urban mobility has introduced a new safety challenge: their low noise emissions. While reduced acoustic pollution is environmentally advantageous, it may impair the auditory detectability of such vehicles by vulnerable road users, such as pedestrians and cyclists. This study aimed to investigate both the noise characteristics and perceptual detectability of electric versus conventional internal combustion engine (ICE) scooters under simulated urban conditions. Noise measurements were taken for two scooters – one electric and one ICE-powered – at three speeds (10, 20, and 30 km/h). Sixteen participants then completed a perception experiment in which they were asked to detect the passing vehicles while visual cues were blocked. Results showed that the electric scooter consistently emitted approximately 8 dB(A) less noise across all speeds. Critically, only 31% of participants failed to detect the ICE scooter, whereas 69% did not perceive the electric scooter. Reaction times were shorter for the electric vehicle when it was detected, but detection occurred at a dangerously close distance (mean ≈ 1.5 m). The findings underscore the need for revised safety regulations and perceptual enhancements for low-noise vehicles. As electric two-wheelers become more prevalent, understanding their impact on pedestrian safety is essential for designing effective urban transportation policies.