A rail pad made of substantially rigid electrically insulating material which is chosen to by yieldable to a predetermined extent, the pad having upstanding rail locating formations on its rail engaging face and oppositely directed pad locating formations on its sleeper engaging face to locate the pad relative to a supporting sleeper, the pad being provided with a series of recesses in its sleeper engaging face wherein the unrecessed area of the face is calculated to be capable of carrying the required load.