Abstract: A highway/rail vehicle has highway wheels and rail wheels which are movable between extended and retracted positions. The vehicle has selectively engageable first and second drives for transmitting power from the engine to the highway and rail wheels respectively. When the vehicle is in a rail going condition with its rail wheels in their extended positions the highway wheels are maintained out of contact with the track rails by deflection restriction devices operable on the suspension devices for the highway wheels. The vehicle also has a sub-frame at the rear on which the rear rails wheels and the bodies of lifting jacks of auxiliary apparatus are mounted. The sub-frame is vertically movable on slides. The auxiliary apparatus may include tamping, packing, leveling and/or lining apparatus.