How many cars on road in America 1970?

There's no precise figure for the exact number of cars *on the road* in the US in 1970. Data collection methods weren't as sophisticated then as they are now, and differentiating between registered vehicles and those actually in use on any given day is difficult.

However, you can find estimates of the number of *registered* vehicles in the US around that time. These numbers would be a reasonable approximation, though still not perfectly accurate to the number actually on the road at any moment. You'll likely find figures in the range of 80-100 million registered vehicles in the US for 1970 from various sources. Keep in mind that this is an estimate and different sources may provide slightly varying numbers.