PURPOSE: To prevent the occurrence of positional dislocation between iron wheels and a rail when a car body is lowered after jacks are housed from a condition where the car body is supported by the jacks.

CONSTITUTION: A track work vehicle 30 is composed of iron wheels 36 which are arranged on a car body 31 and travel on rail R for a railway and jacks 20 which are installed on the car body 31 and can raise and support the car body up to a condition where the iron wheels 36 float from the rail R. A guide member is arranged to prevent positional dislocation between the iron wheels 36 and the rail R by overhanging on the rail R when the iron wheels 36 are put in a condition of floating from the rail R by being raised and supported by the jacks 20.