Well, he was partly right...

"... the automobile, from its humble start as a one-lunged horseless carriage, grew into a steel-bodied monster of over a hundred horsepower and capable of making more than a hundred miles an hour. They boiled over the countryside, like yeast in ferment. In the middle of the century it was estimated that there was a motor vehicle for every two persons in the United States.

They contained the seeds of their own destruction. Seventy million steel juggernauts, operated by imperfect human beings at high speed, are more destructive than war....

...Safe driving campaigns were chronic phenomena, but were mere pious attempts to put Humpty-Dumpty together again. It was not physically possible to drive safely in those crowded Metropolises. Pedestrians were sardonically divided into two classes, the quick and the dead.

But a pedestrian could be defined as a man who had found a place to park his car. The automobile made possible huge cities, then choked those same cities to death with their numbers."

From The Roads Must Roll by Robert A. Heinlein, 1939.

Of course, he then went on to predict that America enters the war in Europe, and declares oil to be a national resource. Rising prices of fuel, and the Yankee refusal to be dependent on foreign sources, see the gradual replacement of individual cars with massive high-speed public transportation by the the end of the 20th century. For the most part, we're still waiting for that. While some cities, like Portland, and San Francisco, have excellent public transportation systems, they are still a distant second in utility to individual automobiles. And inter-city transport is still virtually non-existent unless you want to take a train or a bus that runs perhaps once or twice a day and you don't really care what time you arrive. (Yeah, I'm still pissed at missing most of Batboy the Musical because the damn train took 9 hours to get the 100 miles from Eugene to Portland.)

I'm still waiting for the 300mph Seattle-to-San Diego bullet-train. We could build it. But we won't.

Heinlein severely underestimated what the American public would put up with before they'd start driving less, walking anywhere, demanding adequate public transportation, or, at the very least, a yearly increase in the fuel efficiency of their automobiles.