Yes, there are now vehicles with active (radar-based) cruise control and lane keeping systems that use a camera to read the lane lines and will steer themselves to stay in a lane if no turn signal is activated.
With both systems, this means you can set a cruise speed faster than traffic allows, the radar cruise will keep your vehicle at the same speed and distance as the vehicle you are following, and the lane keep system will do the steering, but the vehicle will drift back and forth from one lane line toward the other.
I did this myself while test driving a Silverado pickup a while back, followed a truck this way on a 2 lane highway for about 10 miles, never touching the controls. Fascinating, and disturbing, all at once. And its definitely not the way these systems are intended to be used.