GOOSE YOU'RE ALIVE! #P
Seriously, the thing about Mad Max was that noone had really done the seriously in-your-face car chases before. Yeah, the opening one is the big one, but the sheer amount of crashyboom as well as all the onboard camera work was new. So was going all-out with the stunts; the Pursuit Special at the end needed much more time to shine but the biker rundown should be noted. There wasn't any kind of safety breakaways or whatnot, they just went straight up for the look and feel. It doesn't hurt one bit that the producer was a doctor and treated all kinds of injuries from crashes on the highways, so he had an idea of what he was looking for.
But things like "oh, bikers take a spill, now watch the second guy's cycle hit the first one's rider in the head" and "okay we're goingto drive these bikes over a concrete abutment, down 30 feet into a river, and if you don't break your neck it's in the final cut" sort of filmmaking were new. That's why I bring up the first Mad Max film. The second was great, and the car chase with the tanker (and the plot knife-twist) was one of the best ones filmed in my opinion.
They're not great movies. They're good movies. But there are great elements in them, that in 1979 and 1981, were still revolutionary. Just like what Star Wars did for miniatures filming and special effects camerawork, the first two MM films did for car chases. Sure there was groundbreaking stuff before it, but they really changed the way people looked at such stunts. And they did it in a very visceral way, which we don't get anymore with all the CGI detachment from the real thing.