In a transportation/logistics system in which a pallet/vehicle with an automobile/container mounted/fixed thereon travels, a normal steering operation is carried out by changing the direction of the wheels (including tires) by an electronically controlled automatic steering system on the basis of steering information, whereby comfortable travel and a smooth turns are obtained. When the pallet/vehicle is about to run off a lane on which it travels, the run-off thereof is prevented physically and mechanically since a fin provided on the pallet/vehicle is inserted in a groove provided in a road, whereby a safe traffic/transportation system is obtained. The pallet/vehicle obtains a driving force by a gap length regulated/controlled linear induction motor so that the pallet/vehicle can travel at high speeds. In diverging (branching) and merging (converging) points, the diverging (branching)/merging (converging) of the pallet/vehicles is practiced by steering the wheels (tires) by the automatic steering system, and the pallet/vehicle advances with the fin inserted in a groove in a main line or a ramp, whereby a reliable, safe traffic/transportation system adapted to practice high-speed diverging (branching) is obtained. At the exit/entrance of the present invention to/from a general road, a mode interchange is provided which is adapted to convert a traveling mode of an automobile/container, and mounts and fixes an automobile/container on the pallet/vehicle and unfastens such automobile/container.