Double-tracking or laying an additional railway line next to the existing one is the largest and most ambitious project ever handled by KTM during in the '90s. It is a RM1.5 billion project spanning almost 5 years during which 288 km of track was laid primarily in the Klang Valley starting from Rawang to Seremban (North -> South) and Sentul to Port Klang (East -> West). The double-track provides and alternative mode of transportation for commuters in this sector and helps alleviate road traffic congestion namely Federal Highway (Kuala Lumpur-Petaling Jaya-Subang Jaya-Shah Alam-Klang).
Double-tracking project is not just the laying of a second track but also involved upgrading the entire railway infrastructure where under the project, some 15 stations, 19 halts, 51 bridges and 272 culverts were replaced and re-constructed with better and modern design. The platforms of the 1995 stations are virtually standardised, down to the design of the passenger semicircle-crossed shelters, the use of similarly-styled pedestrian crossings to link all platforms, and even the diamonds-based brickwork of the platforms. In addition, 400 km of single track is electrified via an overhead catenary system.
The work is complemented by the installation of the latest signalling and communication system to ensure the highest standard of efficiency and safety. The end product of double-tracking is better quality service for the public; better train, greater efficiency and improved quality.
In the past, the only alternative railway transportation for urban transit is provided by KTM Railbus back in the early '90s with 2 scheduled service plying between Kuala Lumpur to Port Klang but eventually the railbus service was terminated in mid '90s due to economic turnmoil. However it was replaced by more sophisticated fleet of electric trains known as Electric Multiple Unit (EMU) for KTM Komuter service which offered environment-friendly rapid transit and fully air-conditioned to provide comfort.
The cost of operating electric commuter trains is approximately 25% lower than diesel trains and utilised a modern proven propulsion package powered from a 25kV AC overhead catenary system. With the electric trains which are environment-friendly, KTM will provide a fast and convenient commuter service. The economic benefits of the project are of major importance. Modernisation of rail transport facilities will contribute to the economic development of Klang Valley which houses the nation's largest manufacturing base.