Tesla's Autopilot
Once you’re on the highway, an autosteering feature can maintain your speed, keep an appropriate distance from the cars around you, and keep you in your lane — even around big bends and turns. It doesn’t just let out a loud beep when you start to drift out of your lane; it physically controls the wheel.
This would be an ideal vehicle for my commuter to Long Beach not to mention getting one of those fancy HOV stickers too!