The Ma On Shan Line was constructed by the KCR to serve Ma On Shan and City One residential areas and operation of the line was outsourced to the MTR. The system mostly runs on a viaduct between the middle of roads with stations, stopping right next to major buildings. The only time the trains don't run on viaducts is when the railway meets the route 2 highway, where it runs in the middle and then raises back to a viaduct. The railway is slightly different from all other Hong Kong railways because the trains run on the right, not the left; this is so that passengers can easily interchange from the Ma On Shan line to the East Rail Line towards Hong Hum. The majority of passengers using the line get off the train at Tai Wai to interchange to the East Rail Line, using the line as a feeder route.