[coryrc]

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

Your former doesn't imply the latter. Here in Seattle we even still have cobblestone roads without heavy traffic and they spend very little money on them.

We have extensive rutting damage on the lanes use by busses and requires more expensive, deeper road base when they get replaced. This cost is due to the heavy traffic.

Even if squared, the buses are still 22 tons instead of 2-3 tons. 49 times more damage isn't good.

[Retric]

22 tons are huge busses and overkill unless you actually need that much space, and tend to have 4 axles. ((22 / 4)/(3/2)) ~= 13.5x a heavy SUV but could be replacing 30+ vehicles.

Also that visible ware is noticeable because it hasn’t been replaced. Looking worse when you resurface on the same schedule isn’t an actual cost.

[coryrc]

But those are what we have and they have 3 axles, not 4.

We also have many concrete roads and closely-spaced axles, if they had them, would not help.

> Looking worse when you resurface on the same schedule isn’t an actual cost.

I addressed this: they have to dig much deeper and replace with much thicker road. Much more expensive. It's not "looking worse", it's actively dangerous to cyclists and other road users, so the surface must be replaced more often too.