I challenge this opinion. If you have any ressources to back your claim, please share!
My estimates for the velocity where tire noise will be substantially louder than the rest of the car are much higher, more like 60km/h.
My estimates for the velocity where tire noise will be substantially louder than the rest of the car are much higher, more like 60km/h.
[1] shows on page 3 a significantly higher tire noise for 50 kph (+8 dbA) but doesn't show lower speeds than 50 kph.
[2] is in German and from the Austrian Federal Environment Agency and states that for cars build after 1996 25 kph is the point where the tire noise takes over at a steady speed and at 50 kph when the car is accelerating.
1: http://www.asphaltroads.org/assets/_control/content/files/an...
2: http://www.umweltbundesamt.at/umweltsituation/laerm/laermsch...
One other thing that came to my mind is that tire noise is usually concetrated in the high frequencies, whereas some cars, especially trucks, emit very low-frequency noises. The latter penetrate walls and windows much more easily.
Of course tire noise won't go away with electric cars, but in my opion there's a vast underestimation of how much quieter roads and cities could be without combustion engines.
Also, with truly autonomous vehicles, travel speed would likely be increased in order to maximize capacity - like it's done with trains, where both speed and minimum distance are chosen for maximum capacity.
And energy efficiency decreases with higher speeds due to air resistance, so saving energy (reducing load on the grid from charging) is also a competing concern.