They don't help as much as mass transit but they help in a couple of ways. The most significant is that we spend a huge amount of inner city land on parking.

They don't help as much as mass transit but they help in a couple of ways. The most significant is that we spend a huge amount of inner city land on parking. We could build denser without worrying about that. A fair amount of inner city traffic is people cruising around looking for parking too. Also, outlying rail or subway stops should really have a lot of development around them but often in the US they're surrounded by parking lots for people commuting in to work. Reducing the need for parking really helps in this case. Also, people currently have to buy a car big enough for their greatest needs. You don't need a large a car when commuting in to work as when you're taking a road trip with your family but if you're thinking of buying a car you need one to do both. So hopefully we see the average car on the road being much smaller than they are now.