The expansion detailed in the LTA's 2013 Masterplan, which was published on January 17, will see the system grow from its current 178km to around 360km in 2030, bringing 80% of homes on the island within a 10-minute walk of a station.

The centrepiece of the plan is the new Cross Island Line, which will span Singapore from Changi in the east to Jurong Industrial Estate in the west, passing through Loyang, Ang Mo Kio, Sin Ming, and Bukit Timah. The line will connect with all other major lines and will provide an alternative route to the existing East-West Line. The entire 50km line will be completed by 2030.

The second new line is the 20km Jurong Region Line, which will serve Choa Chu Kang, Boon Lay, and new developments in the Tengah area. The line will be completed by 2025 and will provide the Jurong area with much-improved connections to the rest of the island, while reliving the busy Jurong East station, which is a major interchange between the East-West and North-South lines.

In addition to the new lines, three extensions are included in the masterplan. The sixth and final phase of the Circle Line will close the 4km gap between Harbour Front, Keppel, and Marina Bay by 2025, providing a direct link between the business district, new developments in the Marina Bay area, and office and retail centres at Harbour Front.

The North East Line will be extended north by 2km to Punggol North by 2030, while a further 2km phase will be added to the Downtown Line, which will be extended beyond Expo to an interchange with the Eastern Region Line at East Coast by 2025. LTA is also studying the construction of a new station on the North-South Line between Yishun and Sembawang in the north of the island.