Car Trap

The Car Trap is one of the three main traps used in the Half-Life 2 chapter "We Don't Go To Ravenholm..." to help kill the many zombies and to help Gordon Freeman get up to areas that would otherwise be inaccessible. It consists of a damaged car that is attached to a system of pulleys that lift it above the ground some distance. At the pull of an attached switch, the car drops out of the air violently and crushes anything below it. A mechanism then starts up, and the car is automatically hoisted back into the air ready for another drop.

They also serve as a sort of mock elevator on one occasion, as Father Grigori set up a wooden plank walkway to a nearby building that is only accessible by climbing onto the one of the cars and riding it up as it automatically resets itself.