They had a alpine slide in Gatlenburg we rode about 20 some years ago. It was like a heavy plastic sled with a handle in the middle to pull back so you could slow down. Racing 15 year old son. I go too fast,fly off rails, son wins. Fun days.
I think the sign says "keep your hands and feet inside the vehicle at all times" or something like that. Looks terrifying. I think I'd take the cable car.