If it takes more than an hour of car travel then how long will it take without a car? I imagine your argument is that without cars the city wouldn't be as big,

If it takes more than an hour of car travel then how long will it take without a car? I imagine your argument is that without cars the city wouldn't be as big, but the math doesn't work out: the travel time is proportional to the square root of the area while the additional area is linear. If a city with cars is triple the size of the same one without it would have taken only 1.7 time more to travel through. Public transit is way slower than 1.7x.