What keeps a car parked at an angle from rolling away?

Question

Like, if a car's parked on a sloping driveway or on a hill, why doesn't it roll away? What makes it stay where it is?

Thanks,

~~Ali. :)

Answer 1

The Park transmission position. IT is a stationary gear, Or in a manual the parking brake plus the fact that we leave it in gear which aren't made to go in the opposite direction, but a steep enough hill make it go backwards (or forwards if you are parked going downhill)

Answer 2

On automatic transmission cars, there is actually a little pin under hydraulic pressure aided by a stationary gear keeping the wheels from turning.  If you lift the car on a hoist, put it in park and try and turn the drive wheels with your hands, it will give just a little, maybe a degree or two or a turn and you'll hear the pin engage.

On Manual transmission cars, you leave it in gear.  If going down hill, you leave it in revers.  If the rear end is going down hill, you leave it in first gear.  These two gears have enough torque in them to keep the vehicle from moving in the other direction.

That and the use of the parking brake.  A spring action lever that applies the rear drum brakes.

Answer 3

On a manual transmission you use your parking brake. On a automatic transmission you use your parking gear. Which mechanically locks your transmission.