> Busses are light compared to 18 wheelers and other heavy equipment, they also replace many cars and SUV’s which keep getting heavier.
They don’t replace nearly enough cars and SUV’s to make up for the difference in fourth power of axle weight. But yes, 18 wheelers are worse.
>They don’t replace nearly enough cars and SUV’s to make up for the difference in fourth power of axle weight
A modest bus holds 40-50 people. Most commuter traffic is single driver, single vehicle. I don't know to which power the difference in axle weight would have to be to surpass the efficiency gains of replacing 40 to 50 American sized SUVs with a city bus, but I suspect it's more than four.