There is a lot of deadly pollution in this world, but noise pollution might often
be considered benign. The deadliness of excessive noise may be debatable, but
whisper quiet electric cars could be future killers. Electric cars are virtually silent
especially at very low speeds. Environments like parking lots are dangerous
now, but consider walking through a mixture of grumbling gas powered cars and
silent electrics. Here is the sound of a Prius driving slowly on gravel:
All you hear is the crunch of gravel beneath the tires. Now imagine that there
was no gravel - would you hear this car coming? It is granted that drivers are responsible
for avoiding hitting pedestrians. However, when a pedestrian reacts unpredictably by walking
briskly in front of your car because they didn't hear you coming, there may not be
enough time to react.
Electric and hybrid vehicle manufacturers are planning to play digitized sounds
to alert pedestrians to electric cars. This is a good idea, but only in certain situations.
Cars are noisy, and the faster they go the noisier they are. It would be wonderful
to travel down the freeway with the windows down and hear ONLY the sound of the wind.
Electronic noisemakers in electric vehicles are appropriate only at those speeds where
pedestrians are at risk for not hearing the cars coming. Otherwise, let's keep these
wonderfully emissions-free vehicles noise-free as well.