Downtown Line 3 will open this year, along with the Tuas West Extension (TWE), bringing the rail network to around 262km in length, the LTA said in a report on Singapore's rail network.
TWE, with four stations, is expected to begin operations in by the middle of 2017, while Downtown Line 3 is scheduled to open at the end of the year, it said
The LTA is considering an extension of the Thomson-East Coast Line from Sungei Bedok to serve the future Changi Airport Terminal 5, further extending it to call at the existing Changi Airport MRT station. This would allow travel from the city centre to any of the terminals in Changi Airport without having to change lines, it said.
Major renewal and upgrading work is underway on existing lines to improve reliability, it said.
Final testing has begun on re-signalling work. Once testing is complete, the LTA will move to the new system "progressively", due to the complexity of the task and the issues reported by other international rail operators who have made the same change, it said.
The new system will allow trains to run closer together, giving a higher train frequency at peak periods that should increase capacity by 20%.
The LTA will also call a tender to replace the 66 trains on the North South and East West lines, as well as improving the backend power supply on these lines, it said. The trains and power lines have been in place since 1987 and are near the end of their life, it said.