I'll caution that the situation that we came out of in the 1950s and today are very different. There are many things that are driving the congestion of the roadways in the US. One is, for sure, the move to more urban environments. Why that is depends on a multitude of factors. I'll caution that we have significantly more people in the US than we did when the Levitt-towns were being made. In `950, ~150 million americans were alive, today there are ~320 million, a 110% increase [0]. I'll also say that anecdotally, people are congregating in urban areas because there is more flexibility and agility there. You used to be able to live in a small rural town and work there just fine. Now, if that steel mill or logging operation goes out, you have to move very far. In a city, you can find another job somewhere, and possible through referrals.

[0]http://www.demographia.com/db-uspop1900.htm