Abstract: A railroad vehicle is provided for movement on rails. The vehicle has a car body and two trucks. Each of the trucks has an outboard and an inboard axle mounted to the truck for pivotal movement about respective vertical axes such that the axles may be moved to a radial position when the vehicle is travelling on curved track. Each of the trucks has a pivotal connection, offset from center toward the outboard axle, between the truck and the car body. Each of the trucks contains a steering mechanism whereby the axles are moved to the radial position when the vehicle is travelling on curved track, with the alignment being obtained in response to the angle through which the truck swivels relative to the car body in traversing the curved track. The steerable trucks are stable provided that certain mathematical relationships set out are satisfied.