Active cruise control is also becoming more common. These systems allow you to set a maximum speed for your car and will then maintain a set distance behind slower cars ahead. That way you don't have to turn the cruise control off every time you're behind a slowpoke.
Most of these systems only work at highway speeds. But some, like the system created by Continental Tevis for the Mercedes-Benz S-class, actually work all the way down to a dead stop. If you're stuck in stop-and-go traffic, you need never touch the brakes or gas. The car does it all for you. When the traffic clears, off you go.
The safety benefit of these systems is that they prevent a common cause of crashes - tailgating.
Even if they don't do the driving for you, radar systems are also the bases for collision warning systems, like in the new Lexus LS, that watch the road ahead and warn the driver of an impending collision.
