> It is easy to build a city where you can reach everything you need within 15 minutes by car.
Not when you account for congestion. Let's pretend that the average driver can accept sitting in traffic for one hour daily, or 30 minutes one way. What happens then is that more and more people will take the car until it's just congested enough to take 30 minutes to go somewhere -- even if the distance at full speed is just 15 minutes.
If you increase capacity more people will take the car until the trip takes 30 minutes again.
This just doesn't happen with less massive modes of transport because accommodating practically infinite amounts of foot traffic requires, comparatively speaking, very little area. Distances have to be shorter, yes, but scaling at a lower rate.
Not when you account for congestion. Let's pretend that the average driver can accept sitting in traffic for one hour daily, or 30 minutes one way. What happens then is that more and more people will take the car until it's just congested enough to take 30 minutes to go somewhere -- even if the distance at full speed is just 15 minutes.
If you increase capacity more people will take the car until the trip takes 30 minutes again.
This just doesn't happen with less massive modes of transport because accommodating practically infinite amounts of foot traffic requires, comparatively speaking, very little area. Distances have to be shorter, yes, but scaling at a lower rate.