Expressway Monitoring and Advisory System (EMAS)

by Cheang, Chee Yew

The Expressway Monitoring and Advisory System (EMAS) is an expressway incident management system that monitors and manages traffic along Singapore’s expressways to ensure the safe and smooth flow of traffic.1 EMAS is part of the Land Transport Authority’s (LTA) plan to use technology to enhance the efficiency of road operations and optimise the capacity of Singapore’s road networks.2 EMAS uses information technology to help the LTA detect vehicle breakdowns, traffic congestion or accidents and respond quickly by sending help to remove obstructions on the expressway.3

How the system works
Traffic along the expressways is monitored by a system of surveillance cameras, the Junction Electronic Eyes System (J-Eyes) and public feedback. The surveillance cameras are powerful cameras installed on high buildings or lamp posts near expressways, while J-Eyes are cameras situated at road junctions.4 These cameras monitor vehicle speed and obstruction along the expressways. The information is fed back to the control centre where operators constantly monitor the cameras.5

Operators will then disseminate information on traffic conditions to motorists via electronic signboards placed overhead and along expressways as well as adjacent to major roads. Information can also be disseminated online and via radio broadcasts and a mobile phone application. Information from EMAS includes traffic conditions, estimated travelling times and recommended travel speeds,6 which are updated 24 hours a day.7 In this way, motorists can make informed decisions to avoid congested roads or be alerted to drive more carefully. In the event of a breakdown, operators will activate the vehicle recovery crew to tow the stalled vehicles away and clear the obstruction.8

Early Development
The idea for an expressway monitoring system was came about in 1986, when the Public Works Department announced that it was installing a monitoring system in the Central Expressway’s (CTE) 2-kilometre long tunnels. The system, which cost $16 million, used cameras and detectors for smoke, heat and gases to monitor the tunnels. If problems occurred in the tunnels, information would be relayed via electronic signs along other roads to divert traffic away from the tunnel.9 Subsequently, on 11 March 1987, then Minister for National Development S. Dhanabalan announced the engagement of consultants to study the feasibility of implementing the monitoring system across the entire expressway network in Singapore.10

The installation of the monitoring system on all Singapore expressways was announced in 1993.11 The first phase, carried out along the CTE, was designed and implemented by Singapore Technologies Electronic & Engineering Ltd at a cost of S$9.5 million.12 The system, named the Expressway Monitoring and Advisory System (EMAS), was launched at the CTE on 21 March 1998 by then Minister of State for Communications, John Chen (Dr). 35 detection cameras along the CTE monitored traffic conditions and transmitted information automatically to the control centre, where operators would verify the information before sending it to 25 electronic signboards on the CTE. From 1 April 1998, selected stretches of the CTE could be viewed online via the websites of the LTA and the Television Corporation of Singapore. By June 1998, the CTE’s emergency SOS phones were also linked to the expressway’s control centre to speed up communication regarding vehicle breakdowns.13

The second phase saw installation carried out along the Ayer Rajar Expressway (AYE), East Coast Parkway (ECP) and Pan-Island Expressway (PIE), at a cost of $36.9 million. Installation was completed along the AYE on 10 November 1999, along the ECP on 3 February 2000,14 and along the PIE by late-2000. By mid-2001, EMAS was extended to the Bukit Timah Expressway (BKE), Kranji Expressway (KJE), Seletar Expressway (SLE) and Tampines Expressway (TPE), covering all 150 km of Singapore’s network of expressways.15

New developments
In July 2008, the LTA announced the extension of EMAS to 10 major arterial roads over the next four years to monitor the traffic flow along these roads.16 The 10 roads, which connect one district to another, were chosen due to their high usage rates. In June 2009, the LTA awarded a $40 million contract to ST Electronics to carry out the extension over two phases.17 Known as the Arterial Variable Message Signs (AVMS), the system was rolled out on 7 May 2012 along six arterial roads in the first phase, and implemented in the other four arterial roads by 2014 in the second phase.18 In 2013, the replacement of 380 EMAS electronic signboards along expressways with new ones that can show graphics and more colour was started.19 The EMAS electronic signboard enhancement for the AYE and KJE was completed in 2015.20

Cheang Chee Yew & Goh Lee Kim

1. Land Transport Authority. (2016, April 25). Expressway Monitoring Advisory System (EMAS). Retrieved 2016, May 6 from OneMotoring website:; Land Transport Authority. (2008, August 7). Electronic signs help motorists [Media replies]. Retrieved 2016, May 6 from LTA website:
2. Land Transport Authority. (2008, February 18). Leverage on technology to optimise road capacity. LT Masterplan. Retrieved from 2016, May 6 from LTA website:
3. Top marks for Singapore’s roads and public transport. (2000, September 10). The Straits Times, p. 3. Retrieved from NewspaperSG.
4. Cameras at 100 junctions. (2001, January 7). The Straits Times, p. 32. Retrieved from NewspaperSG.
5. Yeo, G. (1998, March 22). Up-to-date information on all expressways from year 2000. The Straits Times, p. 2. Retrieved from NewspaperSG.
6. Kaur, K. (1996, December 25). Early warning system for Central Expressway ready by end of next year. The Straits Times, p. 3. Retrieved from NewspaperSG.
7. Land Transport Authority. (2016, April 25). EMAS Work Flow. Retrieved 2016, May 6 from OneMotoring website:; Tan, J., & Lee, H. K. (2001, February 6). Eye in the sky. The New Paper, p. 3. Retrieved from NewspaperSG.
8. Land Transport Authority. (2016, April 25). Expressway Monitoring Advisory System (EMAS). Retrieved 2016, May 6 from OneMotoring website:
9. Tsang, J. (1986, May 5). Electronic monitors for all expressways under study. The Business Times, p. 16. Retrieved from NewspaperSG.
10. Dhaliwal, R. (1987, March 12). Highways to go high-tech. The Straits Times, p. 1. Retrieved from NewspaperSG.
11. Highway camera system to keep traffic flowing. (1993, October 30). The Straits Times, p. 31. Retrieved from NewspaperSG.
12. ST E&E wins $9.5m highway system deal. (1996, December 25). The Business Times, p. 7. Retrieved from NewspaperSG.
13. Yeo, G. (1998, March 22). Up-to-date information on all expressways from year 2000. The Straits Times, p. 2. Retrieved from NewspaperSG.
14. Tan, C. (200, February 3). Emas extended to ECP. The Business Times, p. 30; Traffic updates on ECP. (2000, 2 February). The Straits Times, p. 28. Retrieved from NewspaperSG.
15. Emas will cover all by 2001. (1999, December 6). The Straits Times, p. 45. Retrieved from NewspaperSG.
16. Land Transport Authority. (2008, July 14). LTA to extend EMAS capabilities to 10 major arterial roads. [News release]. Retrieved 2016, May 6 from LTA website:
17. Yong, N. (2009, June 18). LTA aims to ease traffic flow along 10 road corridors. The Straits Times, p. 26. Retrieved from NewspaperSG.
18. Traffic update boards for 6 roads. (2012, April 27). The Straits Times, p. 10. Retrieved from NewspaperSG.
19. Chow, J. (2013, September 14). LTA upgrading electronic signboards. The Straits Times, pp. 8-9. Retrieved from NewspaperSG.
20. Land Transport Authority. (2015, May 14). EMAS enhancement completed on AYE and KJE. [News release]. Retrieved 2016, May 6 from LTA website:

The information in this article is valid as at 2016 and correct as far as we can 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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