Assessing the perceived safety risk from quiet electric and hybrid vehicles to vision-impaired pedestrians

Over 90% of the UK population hears traffic noise at home and approximately 10% regard this exposure as highly annoying. The Environmental Noise Directive 2002/49/EC aims to prevent/reduce environmental noise from sources such as road traffic where necessary and preserve noise quality where it is good.

Potential mechanisms for achieving this include the increased use of quieter vehicles (through reduced powertrain and tyre noise) and low-noise road surfaces. One option for quieter vehicles is the use of vehicles powered by electric motors, either fully electric or hybrid vehicles running in electric mode.

However, groups representing the vision-impaired, both in the UK and internationally, have raised concerns that, due to their low noise, such vehicles may pose an increased accident risk to vision-impaired pedestrians.

The Department for Transport commissioned TRL to investigate the accident risk posed by such vehicles and compare it with that for equivalent vehicles with traditional internal combustion engines, and to determine whether electric/hybrid vehicles are audibly more difficult to detect.

This report presents the findings from the study, based upon a review of accident statistics, a programme of practical measurements to compare the noise of electric/hybrid and internal combustion engine vehicles, and a small-scale subjective assessment of the noise from these vehicles involving visually impaired participants.