Tuen Mun South Extension is a proposed extension of the West Rail Line to the Tuen Mun South station in the vicinities of Tuen Mun Ferry Pier. This station will serve as the future West Rail Line westbound terminus if built. The extension will extend southwards from the current western terminus Tuen Mun Station. The journey time from Tuen Mun South to Tuen Mun is estimated to be approximately 4 minutes. It is planned to run on viaduct, since if it were to continue underground the gradient would be too steep for the trains to run through.