40 years ago there was ABSOLUTELY ABS.

ABS in aviation goes back to the 1950s in planes and the late '60s in cars.

But what percentage of cars on the street had it. I understand it existed but not even disc brakes were nearly as ubiquitous as they are today, let alone electronics control of them.

They came in pretty quick. They were standard on every Cadillac and optional on many Fords by 1971, for instance.