The Tseung Kwan O Line is one of the eleven lines of the MTR system in Hong Kong. It runs from Hong Kong Island to the new town of Tseung Kwan O. The line is indicated with the colour purple. During the morning peak period, the Tseung Kwan O Line needs 15 trains in service to keep 2.7 minute intervals. It currently travels through seven stations in 15 minutes along its route.
This line is the first MTR line with no track on viaducts. The portion of the line between Yau Tong and Po Lam has its concourses set on ground level or above, unlike other stations on the MTR network which have concourses underground. Trains at Yau Tong, Po Lam and LOHAS Park are also at ground level, but are completely covered to minimise noise to the surrounding development. The rest of the line has its tracks below ground level.
According to Rail Projects Under Planning 2000 released by Highways Department; in the North Island Line proposal, the Tseung Kwan O line will extend from North Point Station westwards to Tin Hau Station, and connect up with the western portion of the Island Line.