Cross Island Line

The Cross Island Line (CRL) is a high-capacity Mass Rapid Transit (MRT) line currently under construction in Singapore. It will run in an east–west direction across the planning areas of Changi to Pioneer, passing through Pasir Ris, Hougang, Serangoon, Ang Mo Kio, Bukit Timah, Clementi, Jurong East and Boon Lay. From Pasir Ris, a branch of the line will extend to Punggol. Once fully operational, the roughly 70-kilometre (43 mi) line will replace the East–West Line (EWL) as the longest line on the MRT network, serving approximately 27 stations. It will utilise the CRRC Qingdao Sifang CR151 electric multiple unit (EMU), running in a six-car formation. However, to cater to future demand, the stations on the line will be built to accommodate eight-car trains.

Plans for the line were first announced in 2013. The CRL is envisioned to serve various key hubs including the Jurong Lake District and the Punggol Digital District, offering an alternative east–west connection to alleviate passenger load on the EWL. Shortly after the announcement, calls were made by some nature groups to divert the line tunnels away from the Central Catchment Nature Reserve (CCNR). Nevertheless, after years of assessments and deliberation, the government decided to continue with the original direct route in 2019, citing commuting time, economic factors and long-term energy consumption. The alignment and stations of CRL1 were finalised in 2019, followed by the Punggol branch in 2020 and CRL2 in 2022. The proposed full line is expected to have a daily ridership of over one million in the long term, and to cost an estimated S$40.7 billion.