Electric cars will make cities quieter but not as much as you might think

Lower speed-limit roads and congested areas will see much quieter streets, others not so much

Electric cars are quieter. But how much quieter will traffic really be due to electrification of transportation? Some of the writing on the subject is focused on low-speed pedestrian and cyclist safety. Some of it is focused on reductions in traffic noise as it pertains to the health of people living near roads.

The answer is interesting and complex, as almost everything related to noise and perception of noise is.

Basic traffic noise is a combination of engine noise, tire noise, road noise (different surfaces have different noise characteristics) and wind passage noise. The faster vehicles are traveling the more road and tire noise dominate and the more wind passage noise contributes.

Electric cars almost entirely eliminate engine noise and the relatively high-pitched noise electric motors do emit doesn’t propagate as far. They currently tend to have lower coefficients of drag, reducing wind passage noise at higher speeds, although this is likely to diminish as an advantage as batteries get cheaper and more power and it’s easier just to push air out of the way for stylistic “advantages.”…