Buses are implicitly subsidized by road maintenance spending. Road wear and tear occurs according to the fourth power of axle weight, which effectively means almost all of the wear and tear is incurred by the heaviest vehicles, which include buses.

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Retric 2 hours ago | parent [-]

Roads still need maintenance even if nobody uses them, so a significant portion is split evenly across all traffic.

Busses are light compared to 18 wheelers and other heavy equipment, they also replace many cars and SUV’s which keep getting heavier.

Finally that rule of thumb isn’t really that accurate, “A 1988 report by the Australian Road Research Board stated that the rule is a good approximation for rutting damage, but an exponent of 2 (rather than 4) is more appropriate to estimate fatigue cracking.” Rutting really isn’t that significant in most cases, but can instantly destroy road surfaces when fully loaded construction vehicles etc drive over something once.

	▲	philwelch 2 hours ago \| parent [-]
		> 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.