MacRitchie Viaduct (sometimes also called Lornie Viaduct) is a viaduct in Thomson, Singapore that was built on top of and Thomson Road, with its extension also above . The viaduct is built to allow residents living in the Eastern, Central and Western part of Singapore a high-speed access between the east and the west for the residents who wants to travel from the east to the west or vice versa. The extension of the viaduct was opened on 24 August 2008, and is the first flyover to be constructed over an existing flyover, the . The extension is also part of the Outer Ring Road System, allowing motorists travelling between Queensway and Bartley Road to bypass the city area.