I like this question ... as I'm feeling sometimes that tracks are not really broad enough compared to the cars dimensions.
Shouldn't it be only a FOV question rather ? FOV settings have an effect on both car and track.
Shouldn't they rather have a different effect ? ... a FOV for the car in cockpit and a slightly different effect on the track.
Or is it the way they are done that creates this impression of too narrow track for the cars .... while in fact there's more place than enough for 2 or 3 cars.
The issue is I don't know where you would get a measurement of the track that's more accurate than AC. Like, if a website says a track is "7m wide" and AC has it 6.62m wide... what does that tell you. Just that AC is more right than the website.