Most of the noise at speeds greater than a few km/h is wheel noise and air noise.

The engine noise plays a very small role at higher speeds.

An electric 18-wheeler running down the highway will not be significantly quieter than one with an ICE.

I really like this graphic for that effect: http://www.leiserstrassenverkehr.bayern.de/assets/stmi/vum/s...

Yellow is trucks, blue is cars. Full line is total noise, broken line is noise by wind and tires, dotted is noise by the motor.

Tire noise, specifically, from the rubber flexing and air whooshing as it gets compressed out of the contact patch.

An electric 18-wheeler though could actually wind up a lot quieter- the noisiest thing about them is the Jake brake, and regenerative braking could do that silently.

I don't buy the noise argument. Above a certain speed, wind and tire noise far exceed ICE noise. The pickups I've seen are mostly due to the use of course off-road tires that buzz as they go down the road and the motorcycles won't give up their not-super-legal aftermarket exhausts until people collectively agree to stop running them over.

In a downtown area the speeds are likely not high, and the traffic is likely stop and go, with lots of opportunity for revving engines as drivers jam the accelerator down from a dead stop. My previous apartment had a busy highway on one side, and a busy street with a stop light right before an onramp to said highway. The furious acceleration of cars going from a stop to highway speeds as fast as they can was much worse than the monotonous general highway whooshing sounds.

I've heard this called "breakthrough noise", and whenever I'm walking around and hear an obnoxiously loud noise from a vehicle I exclaim, "My Tesla doesn't make that noise!" Fortunately my walking companions generally find that amusing.

At least on major boulevards around my home and office, where speed limits range from 30 to 40 miles per hour (~64km/h), engine noise is dramatically more significant than tire or wind noise. These major boulevards with three to four lanes per direction are conduits for rigs, buses, and utility trucks with large diesel engines. As a pedestrian, when these things roar by, all I hear is engine noise. Grinding, roaring engine noise. Yes, they have tires, and yes, there must be some wind noise, but right down there at street level, it's all drowned out by the engine.

I agree with the grandparent, if we see these larger vehicles go electric in my lifetime, I will be very happy at the reduction in noise.

I looked this up a while ago, and tire noise accounts for 94% of noise over 60 MPH.

The main thing at (near) steady state noise at higher speeds is how well the car is at mitigating the road noise. At city speeds, having both a Leaf at home and a Toyota Sienna, that the noise from the Leaf is near nothing.

If I'm accelerating to make sure I make it through the yellow light, I never get a roar, an downshift, or anything of that nature. On my Toyota or any large car, that flares up and the noise is appreciable. If you floor it on an ICE at 60 to pass someone, that noise is quite loud, even against the road noise. On my Leaf, it's just road noise. I don't get a loud revving of the engine, just more road noise.

Also, here's a reference for interior cabin noise found here: http://www.auto-decibel-db.com/

Did you accidentally type "stop running over them"? Because if people started running over them, that would be an actual solution.

The other day I was walking through a parking garage as two Volts were heading towards the exit.

It was incredibly eerie how quiet it was, just the sounds of the tires against the pavement, no ICEs running.

There is a safety issue though. I can't tell you how many times I've almost been killed by an electric bicycle while living in Beijing. You can't here them coming at all.

I think this is an issue better-resolved by separating traffic modes. Strapping noise makers on to a vehicle to make it safer is a sort of "pseudo-solution" which hops around solving the core issue.

Electric bicycles traveling that fast probably shouldn't be permitted on the same channel/road that foot-traffic uses. Though I don't live in Beijing so I can't speak to their decision (or lack of) for that.

Likewise, in the U.S. I've seen a few downtown areas try to be "green" by simply throwing some bike lanes on a 5-lane road. It's quite dangerous to ride a bike along that because of the traffic going 35-40mph. Separate that bike lane with bollards, at minimum, or build a separated "sidewalk" for e-bikes and scooters. Putting bicycles on the same road as 3,500 lb vehicles hurtling at 40mph is a joke.

One reason to like Seattle is that they actually have bike trails, not just lane separation with car traffic.

Beijing used to have a lot of such bike lanes in 1999 when I first visited (the land of the sea of bicycles) but sadly all of this has been turned into parking for cars.

I ride by bicycle all over the land of the Model S and have had no issues hearing the various EVs wandering around.

Are you speaking as a pedestrian/cyclist/driver? What kind of speeds are people driving at?

Yes. I'm talking about electric bikes, not EVs, traveling around 10-20km....on the sidewalk.

Hehe. I think that's the difference. It is usually illegal to ride on sidewalks in the US.

If it's an electric bicycle, then since it's now "motorized", simply cannot ride on the sidewalks.

In China, it seems like almost anything goes. ;)