A concrete roadbed for slab track was proposed to decrease the track maintenance work on earthworks. An experimental track was laid for this purpose at a site of the Hokuriku Shinkansen line, and static and dynamic loading tests were carried out. From the above test results, the Japan Railway Construction Public Corp. decided to apply this structure to a route length of 11 km at the above line in 1993. This paper describes a proposal of new structure, static and dynamic loading tests and performance tests under train running.