They also tend to be carrying 5-25x more people than cars, so there are far fewer of them. They also tend to be driving in the city on the busiest streets, whereas arbitrary cars are more often driving on vacant streets and highways.

so try the comparison using (miles x flow) instead of miles if you're measuring safety, and if you're measuring worthwhile risk, multiply that by passenger-miles. If you're talking about pedestrian safety, you'll probably have to square the (miles x flow) because pedestrians are also less safe the busier a street is.

I was directly responding to a comment arguing that bus drivers were more adept at avoiding pedestrian killings than SUV drivers. Unfortunately extra training cannot change the physics of a 40,000 pound hunk of metal.

If you look at passenger-miles (pax in the bus) or some other metric the rate might be lower for buses but that’s not relevant to what I responding.