A roller coaster train is a vehicle made up of two or more carts coupled together by specialized joints which transports passengers around a roller coaster's track. Roller coasters typically have multiple safety features, including specialized wheel assemblies and restraints. The rider vehicle is called a train because the carts are connected in a chain and follow each other along the track, just like a railroad train. Individual carts vary in design and can carry just one to eight or more passengers each.