Abstract: A pair of laterally spaced wheel chocks are each normally connected in a gap in a railroad track rail, with each chock having a straight upper surface over which car wheels can roll in crossing the gap. Pivotally connected on a horizontal axis to each chock is the rear end of an arm, the front end of which is pivotally connected to a support. Means are provided for lifting the chocks after car wheels have rolled across them, whereby to cause the chocks to engage a pair of car wheels and move them forward on the track. The arms guide the upwardly-moving chocks in paths that result in there being substantially no sliding of the chocks against the wheels.