KTM West Coast railway line

After many years of announcements about the intention to upgrade the final stretch of single track of the West Coast Line, the Government began the public display exercise for the Gemas–Johor Bahru electrification and double-tracking project on 27 October 2015. The public display exercise, required for all development of new railways under Section 84 of Malaysia's Land Public Transport Act 2010, ran until 27 January 2016. Chinese company China Railway Construction Company (CRCC) has been awarded to build the Gemas–Johor Bahru electrification and double-tracking project.

The length of the line to be electrified and double-tracked is 197 km between Chainage 563.040 at Gemas to Chainage 754.180 at Johor Bahru. The project includes the construction of 11 stations at Segamat, Genuang, Labis, Bekok, Paloh, Kluang, Mengkibol, Rengam, Layang-Layang, Kulai and Kempas Baru, and 3 future stations at Tenang, Chamek and Senai. The upgraded line is supposed to cater for at least 22 services daily involving KTM ETS, KTM Intercity and shuttle train services. Electrification for the stretch will have the same specifications as that of the Seremban-Gemas stretch, name at 25 kV AC 50 Hz single phase and supplied via an overhead catenary. Train operations for this stretch will be integrated with the Train Control Centres at KL Sentral and Gemas. The design speed for the tracks is 160 km/h.

Construction began in 2016 and is expected to be completed by April 2026.[4][5][6]

The project was implemented by Keretapi Tanah Melayu began in 2016 and phase 1 is expected to be completed by 2021.[7] The project entails the rehabilitation of 42 km of tracks between Rawang and Salak Selatan as well as Sentul and Simpang Batu. This will focus on enhancing 16 stations along these routes and upgrade the existing signalling and electrification system.[8] This will be reduced to just seven-and-a-half minutes once the KVDT is completed.[9]

The 42km rehabilitation under Phase I, which are:

• Phase 1A (Rawang – Simpang Batu)
• Phase 1B (Kuala Lumpur – Simpang Bangsar)
• Phase 2 (Simpang Batu – Kuala Lumpur)
• Phase 3 (Sentul – Simpang Batu)
• Phase 4 (Simpang Bangsar – Salak Selatan)

Phase II is from Simpang Bangsar - Pelabuhan Klang and Salak Selatan - Seremban.

Part of the main trunk line near Kampar

The West Coast main trunk line stretches from Padang Besar on the Malaysia–Thailand border to Woodlands Train Checkpoint in Singapore.

The main trunk line is double-tracked and electrified from Padang Besar to Gemas. From Gemas to the Woodlands Train Checkpoint, the line is single-tracked and not electrified. Loops at stations allow trains to pass. Double tracking and electrification works are currently being carried out.

The West Coast railway line connects with the State Railway of Thailand at Padang Besar, while the East Coast line branches off at Gemas.

The West Coast railway line includes several branch lines from the main trunk line, namely:

• Bukit Mertajam Junction to Butterworth
• Batu Junction to Batu Caves
• Port Klang/Bangsar Junction to Port Klang and Westport, with further branch lines:
  • Subang Jaya to Terminal Skypark at the Sultan Abdul Aziz Shah (Subang) Airport
  • Port Klang to Northport
  • Pulau Indah to various Wesport shipping terminals
• Skudai Junction to the Port of Tanjung Pelepas
• Kempas Baru to Pasir Gudang

The Bukit Mertajam Junction to Butterworth, Batu Junction to Batu Caves, Port Klang Junction to Port Klang station, as well as the branch line to Terminal Skypark is double tracked and electrified.

The line from Port Klang to Westport and its shipping terminals, as well as the branch lines between Skudai Junction and the Port of Tanjung Pelepas and the Kempas Baru and Pasir Gudang are single lines and not electrified.

There are also branch lines where the tracks exist but are not used for any service or closed are:

• Between Tapah Road and Teluk Intan (abandoned and not connected to the main line)
• Between Seremban and Port Dickson
• Between Tasek and Tanjung Rambutan To be removed as is a portion of the old main line that was abandoned after double tracking, and not connected to the new main line, never used and meant as branch line compared to Teluk Intan branch line

None of these disused branch lines are double tracked nor electrified.