Rail system for rolling stock, of the tram type, comprising: - at least one rail; - sleepers; - means for fastening said rail to said sleepers; - protective covers for said means of fastening; and, - an insulating and sealing device; said insulating and sealing device comprising: - a flexible and sealed lower rail splice, of a length corresponding to the distance between two sleepers, comprising a tie plate with a width equal to the width of the rail, extended by two vertical flanges (13, 14), with the tie plate and the flanges delimiting a housing with a shape complementary to that of the base of the rail and intended to receive the latter and the vertical flanges having an upper profile, of which the outer portion corresponds to the upper profile of a protective cover of the means for fastening the rail; and, - a first and second lateral rail splices (22, 23) intended to cover, respectively, on each side of the rail, at least one lower rail splice and a protective cover, the profile turned towards the rail of each lateral rail splice (22, 23) being complementary respectively of the profiles of the two sides of the rail, characterised in that: - the lower rail splice is made from a plastic foam and perfectly surrounds the base of the rail, - the lower profile of each lateral rail splice (22, 23) is, respectively on each side of the rail, on the one hand complementary of the upper profile of the lower rail splice and, on the other hand, complementary of the upper profile of the protective covers, and, - in that each lateral rail splice (22, 23) comprises a longitudinal notch that makes it possible to render its upper portion breakable, and in that the space released by the removal of the breakable upper portion is intended to receive an expansion joint. - at least one rail; - sleepers; - means for fastening said rail to said sleepers; - protective covers for said means of fastening; and, - an insulating and sealing device; - a flexible and sealed lower rail splice, of a length corresponding to the distance between two sleepers, comprising a tie plate with a width equal to the width of the rail, extended by two vertical flanges (13, 14), with the tie plate and the flanges delimiting a housing with a shape complementary to that of the base of the rail and intended to receive the latter and the vertical flanges having an upper profile, of which the outer portion corresponds to the upper profile of a protective cover of the means for fastening the rail; and, - a first and second lateral rail splices (22, 23) intended to cover, respectively, on each side of the rail, at least one lower rail splice and a protective cover, the profile turned towards the rail of each lateral rail splice (22, 23) being complementary respectively of the profiles of the two sides of the rail, - the lower rail splice is made from a plastic foam and perfectly surrounds the base of the rail, - the lower profile of each lateral rail splice (22, 23) is, respectively on each side of the rail, on the one hand complementary of the upper profile of the lower rail splice and, on the other hand, complementary of the upper profile of the protective covers, and, - in that each lateral rail splice (22, 23) comprises a longitudinal notch that makes it possible to render its upper portion breakable, and in that the space released by the removal of the breakable upper portion is intended to receive an expansion joint.