PURPOSE: To permit the rational operation according to the road situation and the amount of passengers by operating a connected car which can travel only the connected state, optionally in cut-off state and connected state according to the necessity.

CONSTITUTION: A front car 2 and a rear car 3 perform the relative movement in a certain range by the aid of a connecting mechanism 5 constituting a connecting apparatus 4 and a connecting mechanism 6. A bellows 8 for the passing of passengers is formed in the connection part C of the front and rear cars 2 and 3. The front car 2 is equipped with front and rear axles 9 and 10, and the rear car 3 is equipped with a rear axle 11, and an engine 12 is installed under the floor of the front car 2. The power of the engine 12 is transmitted to a differential gear 15 through a propeller shaft 14 from a transmission 13, and the rear axle 10 is driven. A steering mechanism 16 is installed onto the front axle 9 of the front car 2. Therefore, even if the both cars are cut-off, only the front car can travel.