Will AVAS for EVs be effective in India ?

As Electric Vehicles [EVs] are known for very quiet while starting and till they reach 20 km/hr either in forward or reverse mode of driving, they might prove to be a dangerous for the Blind, the old with hearing loss and children on road.

On the other hand, current ICE [internal combustion engine] powered vehicles create sound (thanks to firing in their cylinders, exhaust & intake of gases) while approaching pedestrians and thus, the road-users get aware of them.

But since Electric motors generate sound pressure level [SPL] so low that there is a need of providing AVAS (acoustic vehicle alerting system) to all EVs in a form of a speaker which would be active till 20 km/hr to produce an artificial SPL so that the road-users will detect them without a surprize!

Minimum exterior SPL measured at 2 m from an EV (with or without AVAS) should be 56 dBA at its speed 20 km/hr and maximum 75 dBA with a proposed regulation in India (AIS 173 adapted from ECE R138), . Thus, the AVAS speaker output should be adjusted accordingly.

If its sound level is kept on lower side, then a question comes up related to effectiveness of this Alerting in India ....where background noise goes beyond 75 dBA ==== during busy hours of the day, or on highly populated roads

or in the Festival seasons or with a heavy rain-fall around or in high wind zones!

If this takes SPLs produced by the AVAS speaker to be designed always on the higher side, then it will be not only irritating to drivers & passengers of these EVs, but also, cause higher environmental noise pollution affecting areas close to Schools, Hospitals and all residential complexes near the road.

Thus, there will be a need of self-adapting AVAS whose SPL will make the EV measuring (at 2 m on road) always 3 dB higher than the ambient SPL so that the pedestrians will be able to detect the passing by EV. But in that case, cost of ownership of an EV will further go up!

The EV-cabin should be very well sealed and fitted with high sound absorbing insulation on its body panels so as to have the least possible Acoustic Transfer Function between the AVAS speaker and the In-cab. For this purpose, the AVAS sound output should haver mid/higher frequency content more than the lower frequency one.

In a highly populated developing country like India, it looks challenging to balance both safety of the road-users and community noise rise! If the overall background SPL is brought under control with the National infrastructure (like sound-barriers or Trees or quiet roads or intelligent traffic management), then AVAS output even if kept lower, it will be detected by the road-users, right ?