SMART Tunnel

The Stormwater Management And Road Tunnel (SMART Tunnel), E38, is a storm drainage and road structure in Kuala Lumpur, Malaysia, and a major national project in the country. The 9.7 km tunnel is the longest stormwater drainage tunnel in Southeast Asia and second longest in Asia.

The main objective of this tunnel is to solve the problem of flash floods in Kuala Lumpur and to reduce traffic jams along Jalan Sungai Besi and Loke Yew flyover at Pudu during rush hour. There are two components of this tunnel, the stormwater tunnel and motorway tunnel. It is the longest multi-purpose tunnel in the world.

In 2011, the SMART tunnel received the UN Habitat Scroll of Honour Award for its innovative and unique management of storm water and peak hour traffic.

It begins at Kampung Berembang lake near Klang River at Ampang and ends at Taman Desa lake near Kerayong River at Salak South. The project is led by the government, including Malaysian Highway Authority (Lembaga Lebuhraya Malaysia, LLM) and the Department of Irrigation and Drainage Malaysia (Jabatan Pengairan dan Saliran, JPS) and also a company joint venture pact between Gamuda Berhad and MMC Corporation Berhad (MMC).

Route background
The Kilometre Zero of the tunnel is located at Salak Interchange.

History
In 2001 the Government sought proposals for a solution that would allow a typical flood of three to six hours' duration to occur without flooding the city centre. A tunnel that would allow floods to bypass the centre was one way of achieving this, providing it was coupled with temporary storage facilities to keep flows downstream of Kuala Lumpur within the capacity of the river channel. A group led by Gamuda engaged SSP, a large Malaysian consultant engineering firm, and Mott MacDonald UK to develop proposals for a tunnel with holding ponds at upstream and downstream ends of the tunnel.

Construction of the tunnel began on 25 November 2003. Two Herrenknecht Tunnel Boring Machines (TBM) from Germany were used, including Tuah on north side and Gemilang on south side. Gusztáv Klados was the senior project manager of the project.

On 11 December 2003, the 13.2-m diameter Mixshield TBM, Tuah, completed a 737-m section after 24 weeks of excavation. By the end of January 2004, Tuah would start a second drive covering a distance of 4.5 km to Kampung Berembang lake. The motorway sections on the SMART system was officially opened at 3:00PM, 14 May 2007, after multiple delays.

Meanwhile, the stormwater sections on the SMART system began operations at the end of January 2007.

By 18 July 2010 the SMART system had prevented seven potentially disastrous flash floods in the city centre, having entered its first mode 3 operation only weeks after the opening of the motorway.

As of September 2020, the tunnel had activated its fourth mode for the seventh time. During the flash flood on 10 September 2020, the tunnel diverted three million cubic metres of water.

In December 2021, SMART entered Mode 4 for an eighth time, due to the massive flooding caused by heavy rainfall lasting from December 16 to 18. Things would have been much worse in Kuala Lumpur had it not been for the tunnel, which successfully diverted 5 million cubic metres of flood water during the 22 hours it was on full activation.

Functioning
The first mode, under normal conditions where there is no storm, no flood water will be diverted into the system. When the second mode is activated, flood water is diverted into the bypass tunnel underneath the motorway tunnel. The motorway section is still open to traffic at this stage. When the third mode is in operation, the motorway will be closed to all traffic. After making sure all vehicles have exited the motorway, automated water-tight gates will be opened to allow flood waters to pass through. After the flood has ended, the tunnel is verified and cleaned via pressure-washing, and the motorway will be reopened to traffic within 48 hours of closure.

Stormwater tunnel

 * Construction cost: RM1,887 million (US$514.6 million)
 * Stormwater tunnel length: 9.7 km
 * Diameter: 13.2 m (43.3 ft) (outer diameter)
 * Tunnelling method: tunnel boring machine (TBM)
 * TBM type: slurry shield

Motorway tunnel

 * Motorway tunnel length: 4 km
 * Structure type: double deck
 * Ingress and egress: 1.5 km at Jalan Sultan Ismail and Jalan Imbi
 * Length: 1.4 km at Jalan Tun Razak
 * Links: 1.6 km at Kuala Lumpur–Seremban Expressway Links: City Centre near Kg. Pandan Roundabout KL–Seremban Expressway near Sungai Besi Airport

Features

 * World's First Dual-Function Tunnel (Stormwater Management & Road)
 * Longest tunnel in Malaysia
 * 9.7 km (6.03 miles) stormwater by-pass tunnel
 * 4 km (2.49 miles) double-deck motorway within stormwater tunnel
 * The motorway tunnel is suitable for light vehicles only. Motorcycles and heavy vehicles are not allowed
 * Ingress and egress connections to the motorway tunnel linking the southern gateway to the city centre
 * Holding basin complete with diversion and tunnel intake structures
 * Storage reservoir and a twin-box culvert to release flood discharge
 * State-of-the-art operations control room equipped with the latest systems in operations management, surveillance and maintenance of the SMART system.
 * Custom-made fire engine units consisting of two modified Toyota Hilux pickup trucks, parked at two different locations for quick access to the tunnel in case of fire on both carriageways.

Tolls
The SMART Tunnel utilizes an open toll system. Ever since its operation, all toll transactions at this toll plaza are carried out using Touch 'n Go cards, MyRFIDs or SmartTAGs. Cash payments are not accepted.

List of interchanges
The entire expressway had its speed limit of 60 km/h.

In popular culture
The tunnel was featured in the below series:
 * Season 4, Episode 2, of Extreme Engineering, titled "MegaTunnel", on the Discovery Channel.
 * An episode of Truly Malaysia on the National Geographic Channel and TV1.
 * Season 2, Episode 3, of Man Made Marvels, titled "Kuala Lumpur: Flood Control", on the Science Channel.
 * Season 4, Episode 2, of Megastructures on the National Geographic Channel and TV1.
 * Season 1, Episode 2 of Build It Bigger on the Science Channel.