Described are the structural features and main technical parameters of the two system low floor tram train in Saarbrücken city in Germany.

The advantages of the “toy bricks”type modular design are expounded with load carrying structure of the COMBINO ○R carbody of the low floor LRV as an actual example.

The light transit with the advantages such as huge capacity, little pollution, saving power, relatively small investing and short construction cycle has been adopted widely, especially the 100% low floor light rail vehicle which provides more convenience to the children and handicapped have been developed quic.