Kallang-Paya Lebar Expressway (KPE)

Singapore Infopedia


Kallang-Paya Lebar Expressway (KPE), Singapore’s ninth expressway, was fully opened to traffic on 20 September 2008.1 Stretching 12 km from East Coast Parkway (ECP) to Tampines Expressway (TPE),  KPE includes a 9-kilometre-long tunnel, which was the longest underground road in Southeast Asia when it was completed in 2008.2 Built to improve connectivity between the northeastern parts of Singapore and the city, KPE cuts the travel time from areas such as Sengkang and Punggol to the city by up to 25 percent.3 It also reduces traffic on Central Expressway (CTE) and improves the connectivity between three major expressways –ECP, TPE and Pan-Island Expressway (PIE).4

KPE is a combination of two expressways – the 2.8-kilometre Kallang Expressway (KLE) that links ECP to PIE, and the 9.2-kilometre Paya Lebar Expressway (PLE) that connects KLE to TPE. KLE was part of a 1967 government plan to build a network of nine expressways across Singapore, while PLE was added to the transport plan in the mid-1980s after the government completed its North-East Sector Study (1985–86).5 The combined expressway, now known as KPE, was included in the revised Concept Plan of 1991, which mapped out the broad directions for Singapore's long-term development.The government approved the funding for the project in early 2001, and the first major contract was awarded in October 2001.7

With the project’s overall bill amounting to S$1.74 billion,KPE was the most expensive road project by the Land Transport Authority (LTA) then.8 A total of six civil works contracts were awarded.9 The contracts included specifications for the design and construction of the underground portion of the expressway (between ECP and Defu Lane 3), the construction of several road interchanges and six ventilation buildings, and the construction of the ground level portion for the last 3 km stretching from Defu Lane 3 to TPE.10

When planning the project, the LTA sought to minimise the amount of land that would be used for the expressway. This was done by constructing three quarters of the expressway underground, with the tunnel snaking under built-up areas, Geylang River and Pelton Canal, and large water and gas pipes. Extra measures were taken to monitor and mitigate the effects of the construction work on nearby structures.11

The tunnel was built using the cut-and-cover method. A deep trench was first dug, after which the road tunnel was built within the trench, and finally the trench was filled in to bury the completed tunnel.12 When KPE was being built, various roads, a river and a canal were realigned temporarily, so that the tunnel could be dug. They were reinstated after construction was completed. Temporary dams were built for Geylang River, so that a road tunnel could be built under it.13

With the help of 103 closed-circuit television cameras and 188 detection cameras, the KPE Operations Control Centre monitors the traffic situation on the expressway, especially the tunnel, 24 hours a day. In addition, the centre will be alerted if the automatic accident-detection cameras pick up something unusual, such as a vehicle remaining stationary for too long in the tunnel.14

State-of-the-art fibre-optic heat detectors monitor the temperature in the tunnel and will activate an alarm in the event of a fire. Sensors monitor carbon monoxide levels in the tunnel. When the level of carbon monoxide gets exceedingly high or when there is a fire, the ventilation system will be activated to extract the exhaust fumes or smoke out of the tunnel. Emergency cabinets holding fire extinguishers and fire alarms are situated very 50 m along the tunnel, with every alternate cabinet containing an emergency phone to allow communication with the control centre. Escape stairs to the ground level every 500 m and cross passage doors allow emergency vehicles and people to move from one tunnel to another during accidents.15 Fire protection in the tunnel is enhanced by a water mist system to be installed by 2022. This plan was put in place after a taxi caught fire in the KPE tunnel on 29 August 2017 and triggered an evacuation.16

With the opening of Singapore’s 10th expressway – Marine Coastal Expressway (MCP) – on 29 December 2013, KPE became linked with Ayer Rajah Expressway and East Coast Parkway (ECP) through MCP.17

Safety education programme 
The LTA implemented a comprehensive programme to promote safe driving in the tunnel and educate motorists on the emergency procedures. It engaged an advertising company to launch an awareness campaign in 2007, its first ever for a road project, and delivered its message through various means, including

  • newspaper advertisements;

  • banners on overhead bridges and lamp posts;

  • inserts distributed with the four major English, Chinese, Malay and Tamil dailies;

  • Sounds of the Underground, a compilation album of 10 songs available for free download on the KPE web portal; and

  • KPE Underground Radio, a half-hour segment that aired on MediaCorp Radio stations for five days in October 2007.18

Construction challenges
As Singapore's longest subterranean road, KPE was the most complex road project undertaken by the LTA then.19 According to five international experts on LTA’s Engineering Review Board, KPE was one of the most difficult projects in the world then, as the construction involved weaving through tight spaces between buildings, pipes and cables, and tunnelling beneath Geylang River, where the ground was soft. Two temporary dams had to be built to facilitate the tunnelling.20 The following challenges faced by the LTA show the complexity of the construction:

  • KPE cut across built-up residential and industrial areas such as MountbattenGeylang and Paya Lebar.21 Some buildings were just 5 m away from the excavation sites.22

  • At the section that ran along Airport Road, KPE crossed the path of a taxiway that allows aircrafts to be moved between Paya Lebar Airbase and the hangars of Singapore Technologies Aerospace. Work was suspended whenever aircrafts had to be moved.23

  • KPE cut across Geylang River at the section between ECP and Nicoll Highway. It also ran directly beneath Pelton Canal for 2 km at the section between PIE and Ubi Road 2. The river and the canal had their courses altered during the building of the tunnel, but were returned to their original alignment after construction was completed.24 The soft ground under the river and the canal's proximity to residential developments also made the job harder.25

Apr 2001: The government acquires about 47,618 sq m of land for the project, mainly at Geylang Lorong 2, 4, 5 and 7, Upper Paya Lebar Road, Airport Road and Defu Industrial Estate.26
Oct 2001: Contract 421 is awarded to SembCorp Engineers & Constructors for S$235 million.27
Dec 2001: Contract 422 is awarded to a joint venture between SembCorp Engineers & Constructors and Daewoo Engineering & Construction for S$257 million.28
Jun 2002: Contract 423 worth S$364 million is awarded to Samsung Corporation (Engineering & Construction Group).29 Taisei Corporation clinches Contract 424 for S$251 million.30
June 2002: Construction begins.31
Aug 2003: Contracts 425 and 426 are awarded to Chan & Chan Construction and Chye Joo Construction respectively.32
Mar 2006: The LTA appoints a team from French motorway operator, Autoroutes Paris Rhine Rhone, to review the design, systems, operational procedures and training processes of the KPE project.334
27 Jul 2007: The LTA launches a dedicated web portalwww.kpeunderground.sg, to provide information on route navigation, restrictions and prohibitions, safe tunnel-driving habits and emergency procedures.34
25 Oct 2007:The Tunnel That Moved a River, an LTA documentary on the KPE’s construction, airs on Channel NewsAsia.35
26 Oct 2007: Phase 1 of KPE, the section between ECP and PIE, opens to traffic.36
14 Sep 2008: Swing KPE, a run organised by the LTA, takes place in KPE. A Guinness World Record for the largest lantern parade is set during the event.37
17 Sep 2008: The team from Autoroutes Paris Rhine Rhone declares KPE safe to open.38
19 Sep 2008: Prime Minister Lee Hsien Loong officially opens KPE.39
20 Sep 2008:  KPE fully opens to traffic.40

1. Desmond Ng, “KPE by Numbers,” New Paper, 20 September 2008, 12. (From NewspaperSG)

2. Land Transport Authority Singapore, Annual Report 2000/2001 (Singapore: Land Transport Authority, 2001), 28. (Call no. RCLOS 354.595700878 SLTAAR-[AR]); Land Transport Authority Singapore, “Transcending Travel: A Macro View,” Annual Report 2007/2008 (Singapore: Land Transport Authority, 2008), 30 (Call no. RCLOS 354.595700878 SLTAAR-[AR]); Yeo Cheow Tong, “The Kallang Paya Lebar Expressway Contract Signing Ceremony,” speech, 11 November 2002, transcript, Ministry of Information, Communications and the Arts. (From National Archives of Singapore document no. 2002111101); Maria Almenoar, “Safety First for KPE Tunnel,” Straits Times, 17 September 2008, 26. (From NewspaperSG)
3. Cheong, Building Singapore’s Longest Road Tunnel: The KPE Story (Singapore: SNP Editions, 2008), 19 (Call no. RSING 624.193095957 CHE); Land Transport Authority Singapore, “ Transcending Travel,” 30.
4. Ng, “KPE by Numbers.”
5. Cheong, Building Singapore's Longest Road Tunnel, 19, 22.
6. Urban Redevelopment Authority (Singapore), Living the Next Lap: Towards a Tropical City of Excellence (Singapore: Urban Redevelopment Authority, 1991), 12, 14, 38. (Call no. RSING 307.36095957 LIV)
7. Land Transport Authority Singapore, Annual Report 2000/2001, 28; Cheong, Building Singapore's Longest Road Tunnel, 33.
8. Cheong, Building Singapore's Longest Road Tunnel, 19.
9. “Biggest Road Project in Singapore Takes Off,” Southeast Asia Construction (November–December 2002), 8 (Call no. RSEA 338.476900959 SAC); Christopher Tan, “LTA Awards $1B Worth of Contracts for Circle Line, KPE,” Business Times, 29 June 2002, 6; Goh Chin Lian, “KPE One of Toughest Projects in the World,” Straits Times, 24 August 2004, 4. (From NewspaperSG)
10. Cheong, Building Singapore's Longest Road Tunnel, 30, 32–33.
11. Cheong, Building Singapore's Longest Road Tunnel, 25, 29; Goh, “KPE One of Toughest Projects in the World.”
12. Cheong, Building Singapore's Longest Road Tunnel, 31–32.
13. “Biggest Road Project in Singapore Takes Off,” 8–9; “Everything’s New, Nothing Has Changed,” Straits Times, 25 October 2007, 45; Goh, “KPE One of Toughest Projects in the World.”
14. Almenoar, “Safety First for KPE Tunnel”; Cheong, Building Singapore's Longest Road Tunnel, 131, 134; Land Transport Authority Singapore, “Kallang-Paya Lebar Expressway (KPE),” 3 December 2014 (From NLB’s Web Archive); “Many Eyes on Tunnel Expressway,” Straits Times, 12 September 2008, 4. (From NewspaperSG)
15. Almenoar, “Safety First for KPE Tunnel”; Cheong, Building Singapore's Longest Road Tunnel, 129; Land Transport Authority Singapore, “Kallang-Paya Lebar Expressway (KPE).”
16. Lim Min Zhang, “Fire in KPE Tunnel Leads to Evacuation,” Straits Times, 30 August 2017, 1; Adrian Lim, “KPE, CTE Tunnels to Get Water-Mist System to Fight Fires,” Straits Times, 5 October 2017, 4. (From NewspaperSG)
17. Christopher Tan, “Undersea Road Opens in Dec, ECP to Be Cut Off,” Straits Times, 14 November 2013, 1. (From NewspaperSG)
18. Cheong, Building Singapore's Longest Road Tunnel, 150; Land Transport Authority Singapore, “Kallang-Paya Lebar Expressway (KPE)”; “Sounds of the Underground,” Straits Times, 25 October 2007, 43; Christopher Tan, “It's the First-Ever Ad Blitz – for a Highway,” Straits Times, 27 November 2006, 3. (From NewspaperSG)
19. Christopher Tan, “KPE Stretch to Close Ahead of Full Opening,” Straits Times, 2 August 2008, 50; “Challenging Expressway,” Today, 11 November 2002, 1 (From NewspaperSG); Cheong, Building Singapore's Longest Road Tunnel, 11.
20. Goh Chin Lian, “KPE One of Toughest Projects in the World,” Straits Times, 23 August 2004, 4. (From NewspaperSG)
21. Cheong, Building Singapore's Longest Road Tunnel, 29, 48; Goh Chin Lian and Alexis Hooi, “Giant Smoke Stacks to Air New Expressway,” Straits Times, 29 October 2003, 1. (From NewspaperSG)
22. “All Set, Ready to Go,” Straits Times, 25 October 2007, 44. (From NewspaperSG)
23. Cheong, Building Singapore's Longest Road Tunnel, 29; “Logistical Problems,” Straits Times, 23 August 2004, 4. (From NewspaperSG)
24. Cheong, Building Singapore's Longest Road Tunnel, 25, 32–33, 46–47, 62–63; Everything’s New, Nothing Has Changed.”
25. Cheong, Building Singapore's Longest Road Tunnel, 47, 62, 95; Ahmad Osman, “Smart Tunneling,” Straits Times, 28 May 2009, 116. (From NewspaperSG)
26. Ministry of Information, Communications and The Arts, “Circle Line and Kallang/Paya Lebar Expressway,” press release, 28 April 2001. (From National Archives of Singapore document no. 2001042808)
27. Cheong, Building Singapore's Longest Road Tunnel, 32; Christopher Tan, “SembCorp Unit Wins $235M Expressway Deal,” Business Times, 12 October 2001, 3. (From NewspaperSG)
28. Cheong, Building Singapore's Longest Road Tunnel, 32; “Firms Wins $257M Contract to Build Tunnel,” Straits Times, 14 December 2001, 6. (From NewspaperSG)
29. Cheong, Building Singapore's Longest Road Tunnel, 33; Land Transport Authority Singapore, Annual Report 2002/2003 (Singapore: Land Transport Authority, 2003), 46. (Call no. RCLOS 354.595700878 SLTAAR-[AR]); Land Transport Authority Singapore, “Kallang-Paya Lebar Expressway (KPE).”
30. “Challenging Expressway”; Cheong, Building Singapore's Longest Road Tunnel, 33; Land Transport Authority Singapore, Annual Report 2002/2003, 46; Land Transport Authority Singapore, “Tunnel Builder: Kallang-Paya Lebar Expressway,” updated 19 October 2007. (From NLB’s Web Archive)
31. Land Transport Authority Singapore, Annual Report 2002/2003, 3.
32. Cheong, Building Singapore's Longest Road Tunnel, 33; Land Transport Authority Singapore, Annual Report 2003/2004 (Singapore: Land Transport Authority, 2004), 3 (Call no. RCLOS 354.595700878 SLTAAR-[AR]); Land Transport Authority Singapore, “Tunnel Builder.”
33. Maria Almenoar, “KPE Gets Green Light from Safety Assessors,” Straits Times, 18 September 2008, 35. (From NewspaperSG)
34. “Sounds of the Underground”; Shermaine Wong, “A Song to Drive Home the Message,” Today, 16 September 2008, 44. (From NewspaperSG)
35. “KPE Phase One UnveiledConnect (October/November 2007), 2 (Call no. RSING 388.4095957 C); “Page 47 Advertisements Column 1,” Straits Times, 25 October 2007, 47. (From NewspaperSG)
36. T. Rajan, “3-km Tunnel Linking PIE and ECP Opens in October,” Straits Times, 28 July 2007, 3. (From NewspaperSG)
37. Sumathi V. Selvaretnam, “Lighting Up KPE with Record Lantern Bid,” Straits Times, 15 September 2008, 24; “Attempt at Lantern Parade Record,” Straits Times, 19 September 2015, 2. (From NewspaperSG)
38. Almenoar, “KPE Gets Green Light.”
39. Lee Hsien Loong, “The Official Opening of Kallang-Paya Lebar Expressway Phase 2,” speech, 19 September 2008.
40. “Drive, Run through Full KPE, before It Opens,” Today, 8 August 2008, 14 (From NewspaperSG); Land Transport Authority Singapore, “Transcending Travel,” 14.

Further resources
Maria Almenoar, “Toll Gantries on KPE Built as Safety Precaution,” Straits Times, 29 August 2008, 47. (From NewspaperSG)

Christopher Tan, “Extra Level of Checks for KPE Project,” Straits Times, 8 September 2004, 6. (From NewspaperSG)

Christopher Tan, “Traffic Marshals to Ply Expressways to Clear Jams Quickly,” Straits Times, 26 October 2007, 54. (From NewspaperSG)

The information in this article is valid as at June 2021 and correct as far as we are able to ascertain from our sources. It is not intended to be an exhaustive or complete history of the subject. Please contact the Library for further reading materials on the topic.


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