[wffurr]

Combustion engine is only louder below about 35 mph.

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

"...rolling tires driving on pavement is found to be the biggest contributor of highway noise which increases with higher vehicle speeds."

[dashundchen]

In the US there are plenty of poorly maintained vehicles on the road emitting a lot of other nosies - squeaky belts, damaged or missing mufflers, rattling panels, worn brake rotors or pads.

Most states have very lax inspection requirements.

Even in my state, which supposedly is one of the strictest on inspections, it's surprisingly easy to have a dangerous failing car pass.

Living near a busy intersection you hear all sorts of weird mechanical failures as cars brake and accelerate from the stoplight.

[wffurr]

While a highway with high speed traffic sounds like a loud whooshing sound, from tires on pavement and air displacement. Engine sounds are almost impossible to notice.

Intersection sounds like <35 mph, so you are agreeing with me.