Comment by tzs

That 4th power law works both ways. A 40 ft bus 2 axle bus with 80 passengers will weigh about 40 000 pounds. The axle weight is 20 000, so by the 4th power law the damage is proportional to 2 x 20 000^4 = 3.2 x 10^17.

If instead those 80 passengers each drove alone in a Kia Niro EV it would be about 4 000 pounds each, so an axle weight of 2000, so the damage would be proportional to 160 x 2000^4 = 2.56 x 10^15.

That's 125 times less road damage than the bus!

Another interesting 4th power calculation is EV vs ICE. My car is available as an ICE, a hybrid, or an EV. I've got the EV which weighs more than the ICE.

Based on the 4th power law I should be doing about 40% more damage than I would if I had bought the lighter ICE model.

But wait! With the ICE model I'd need to regularly by gasoline, and that gasoline is delivered by a tanker truck. Tanker trucks, especially when they are traveling between wherever they load and wherever they unload, are very heavy.

I calculated what would happen in a hypothetical city where everyone drove the ICE version and then all switched to the EV version, and how many tanker truck gas deliveries that would eliminate. I don't remember the exact numbers but it was something like if mid sized tankers were used for gas delivery then if they had to drive more than a few miles from wherever they loaded up to wherever they unloaded the elimination of those trips by everyone switching to EV would reduce road damage by more than the damage caused by the EVs being heavier than the ICE cars.