Hacker News Reader

Comment by willvarfar | Hacker News Reader

In the old horse days in Europe (and presumably everywhere else too) lots of very nice houses were built next to roads. Nowadays as I drive past I pity them and the ugly sound-deflecting fencing and berms they have to invest in to make them habitable. I look forward to quieter cars rejuvenating these old houses.

UPDATE: so my hopes are dashed :(

View on HN

Unfortunately electric cars won't solve that problem. The graph on http://www.leiserstrassenverkehr.bayern.de/laerm/entstehung/ (a German government website) compares the engine noise ("Antriebsgeräusch") with the tire noise ("Rollgeräusch") for different speeds ("Gesamtgeräusch" means "total noise"). The yellow line is for trucks, the blue lines for cars.

As you can see at a speed of 40 kph (25 mph) a car's tire noise is already higher than the engine noise and at even higher speed the engine noise doesn't really matter anymore. So even if your electric car engine is absolute silent, the total noise at speeds above 30 mph won't be all that different.

Indeed. The engine noise is relevant for Formula 1, however, because high-performance race cars generally have much louder engines than commercial cars.

Until they went for these bloody 6-cylinder turbos that the formula is using now. They're nowhere near as loud or as impressive as either the v8's of the 00's, or the v10's and v12's of before.

Even being televised, they've got to jack up the volume to try and make it seem more exciting.

This is a common misconception about roadway noise pollution.

Electric Vehicles will still generate a fair amount of road noise pollution. There will be important improvements for city quality of life, mostly in reductions in the sub 35kmh acceleration/deceleration moments. But for highway speeds the reductions will not be that big.

Check this interesting wikipedia article for reference.

Linking to the part that lists the basic variables that affect Roadway Noise:

https://en.wikipedia.org/wiki/Roadway_noise#Description_of_b...

My house fronts on a 4 lane parkway. As soon as I wake up, I can tell whether or not the road out front is wet from the increased tire noise. (And indeed, we have a wooden fence of maximum legal height, set on top of some earthworks, and double-pane windows to cut the noise down to acceptable levels and I can still readily tell the difference.) The objectionable [to me] noise is mostly from tires.

Every so often, we get someone on a sport bike or sports car ripping along the parkway having some fun. That's very intermittent and far more often brings a smile to my face as I'm reminded that we can still do that...

I don't think it's entirely a misconception. Yes, some people mistakenly think that an all-EV world will be totally silent, and it won't, but the noise reduction is still huge. In most situations, the average is much less important than the maximum, so the fact that typical noise from modern cars is mostly tires and air is irrelevant. Trucks, motorcycles, and performance cars are what make up the bulk of the annoying noise, and EV versions of those would help a lot.

True, it would help a lot in city centers where tipically cars have to accelerate from a stop at lights, but not on highway style roads.

Even there, the constant drone of tires is far more tolerable than the occasional blatttt of sports bikes or the rumble of a tractor trailer.

I would imagine the noise thrown off by tires (tire contact with road) is enough to still present problems for these neighborhoods.

I think the horses (hooves, rattling coaches with no rubber tires) may have made more noise than that.

But not everyone had a horse carriage back then.

Horses were shod and wheels were usually metal rimmed. Even muddy tracks have stones in them, and often roads were 'metalled' or cobble stoned.

I've done a lot of horse driving as a hobby and can attest to how loud it is, particularly metal rimmed wheels on cobble stones.

A main source of noise are the tires, especially at higher speeds. Electric engines do not help in this regard.

Reply on news.ycombinator.com