[acdha]

They tried nothing else for the better part of a century, but the traffic just kept getting worse: the more you subsidize driving, the more people choose to do it.

The underlying problem is basic geometry: cars are the least spatially efficient form of transportation in common use - you need something like 140 square feet to transport on average just over one person, plus a similar amount of space for storage. That can work somewhere unpopular but the math just doesn’t work in a city core where you don’t have that much space unless you bulldozed all of the buildings. Even if they did something phenomenally expensive and unpleasant like creating multilevel streets those would fill up quickly because if traffic ever improved, more people would start driving all the way in.