Because public transit, done well, is the fastest way to move around. It gets you everywhere, even to places personal vehicles can't reach. It's a lot cheaper. It generates hubs of activity that keep cities lively and relevant. It doesn't get stuck in traffic. It doesn't need to be parked.
The benefits of good public transport are so mind blowing that it's difficult to explain unless you have lived on a city that has it.
The benefits of good public transport are so mind blowing that it's difficult to explain unless you have lived on a city that has it.