Look at Life: Living with cars
"By 1970, there'll be 18 million cars on the road. Inside 40 years, 40 million."
Inside 40 years was seven years ago, and at the most recent count (June 2013) we were at 35 million vehicles, of which 29 million were cars. And we're still building more motorways. There are a few bicycles sprinkled around in the video, but I guess everyone wanted to own a car back then.