[catalogia]

I'm surprised that noise propagates far enough for you to hear. In my experience, the noise that propagates furthest from roads is the low frequency tire rumble.

[sova]

Hypothesis: you are both correct, your respective acoustic environs different

[jacquesm]

Here it's the tires moving across the seams between adjoining panels on bridges that make the most noise, those you can pick up from very far away.