That's reasonable - the source I checked didn't use the fourth power, and it was taking into account the number of wheels as well. Anyway, I think the point still stands that just like cars there is a place for busses in a more sensibly designed transit system, despite this one specific disadvantage. Bikes are obviously superior in many ways to other transport but are only really practical over quite short distances (I'm not averse to cycling 10+ miles to get somewhere but I'm gonna need a shower when I arrive lol).