The Jalopnik Team took Tesla’s Model S ‘Autopilot System’ out for a test on the streets of New York City and it’s pretty remarkable (full review here). The team explains:

It won’t drive you to your ultimate destination, it won’t make navigational turns without your input, and it doesn’t know what the traffic light or the sign in front of you says. So think of it less like an autonomous system, and rather more like the ultimate execution of cruise control. It uses a forward-looking radar, a front-facing camera, 12 ultrasonic sensors, and GPS to make sure everything stays on the road. [source]