Speed Limit Button
A button on your steering wheel where you can activate speed limit mode. Most modern cars have GPS and know (usually) what the posted speed limit is. You can hit the button and your car will automatically go the speed limit. The brake and gas pedal still work, you can speed up or slow down. Once you take your foot off, the car will resume speed limit mode. When you brake to below a certain speed (ie stopping or turning), the mode is deactivated. Now you can go the speed limit without constantly adjusting your foot on the gas pedal or watching the speedometer.