I live in the center of a city of ~230,000 and the top contributor to automobile noise absolutely seems to be tire noise even at normal urban speeds of roughly 30 to 50 km/h. I suppose traffic is generally calmer and traffic flow smoother here than in, say, large US cities or other parts of the world where people's driving habits are more aggressive. On the other hand, wet streets and studded tires amplify tire noise by a large factor (and most drivers insist on studs even though urban conditions almost never call for them, and non-studded winter tires would be a more appropriate choice).