The city bus comparison is uneven, but if we consider peak travel times during the week, the density intuitively seems like it works out to less waste. City buses have their numbers and schedule dialed back when you're not in peak hours, and I suspect that it's peak hours where you see the bulk of waste from tires.
My city buses in peak travel hours have anywhere from 20 to 75 people on them. Even if we assume that every one of those folks would have carpooled (which rarely happens), we're looking at a lot of cars, and thus tires, on the road.
> The city bus comparison is uneven, but if we consider peak travel times during the week, the density intuitively seems like it works out to less waste. City buses have their numbers and schedule dialed back when you're not in peak hours, and I suspect that it's peak hours where you see the bulk of waste from tires.
This is really the problem with buses outside of extremely high density areas. (And extremely high density areas should have subways.)
You get off work at 5PM, you want to go to an entertainment venue and then go home at 10PM. You can find a full bus a 5:15PM that will take you there because it's rush hour, but then you can't get home on the bus because there is no bus service after 9PM. Which means you can't take the bus there during rush hour either, because you need your car to be there so you can get home.
Or, you can run mostly-empty buses in the darkness hours, but there goes your efficiency.
My city buses in peak travel hours have anywhere from 20 to 75 people on them. Even if we assume that every one of those folks would have carpooled (which rarely happens), we're looking at a lot of cars, and thus tires, on the road.