Road Tunnel Operations & Safety

Singapore is a built-up city state with limited land space. To cater for growth, LTA needs to efficiently integrate land use for transport planning. One of the solutions is to expand our underground road network.

Besides being built around a densely developed urban environment, our road tunnels need to cater for high traffic volume, peak hour congestion and multiple entrances and exits. These pose challenges to traffic and incident management including tunnel emergencies, and planned and unplanned tunnel closures.

The Intelligent Transport Systems Operations Control Centre (ITS OCC) works around the clock to monitor traffic and manage incidents on our expressways and road tunnels using the i-Transport and various ITS.

Watch this video or download the Road Tunnel Safety Guide (PDF, 1.6MB) for more information on safe driving in road tunnels. 

                         Did You Know icon        





  • Besides road tunnels along expressways, there are shorter road tunnels along some arterial roads to improve local traffic conditions.
  • Road tunnels include the Central Expressway (CTE), Kallang-Paya Lebar Expressway (KPE), the Marina Coastal Expressway (MCE), Fort Canning Tunnel, Woodsville Tunnel (WVT), Sentosa Gateway Tunnel (SGT) and the upcoming North South Corridor (NSC).
  • In the event of a fire, all road tunnels are equipped with a ventilation system to push smoke out of the tunnel.
  • In line with National Fire Protection Association (NFPA) standards, newer tunnels such as WVT, SGT and MCE are equipped with overhead water sprinkler systems to aid fire fighting. The CTE and KPE tunnels will also be upgraded with fire suppressant systems by 2022.
  • Tunnel lighting consists of base and reinforced lighting to assist motorists to adapt to changes in the lighting level from bright ambient outdoor to tunnel lighting.

We have in place electrical and mechanical systems to keep our road tunnels safe such as the Uninterrupted Power Supply System and Generator where critical equipment such as the communication, lighting, traffic control and monitoring systems are supported by Uninterrupted Power Supply (UPS) in the event of major power failure to prevent disruption to operations.

Ventilation system in the tunnel
Ventilation system in the tunnel
Overhead water sprinkler system in tunnels
Overhead water sprinkler system in tunnels

The ventilation and fire protection systems, and equipment, help to keep the temperature in the tunnels acceptable and provide support in case of fire.

  • The ventilation system measures parameters such as visibility, carbon dioxide quality, temperature and velocity of air travel.  If these markers exceed certain values, jet fans fitted along the tunnel will be activated to improve the air quality and keep the environment appropriate for motorists. In the event of fire, the ventilation system will push smoke out of the tunnel.

  • Tunnels are equipped for fire protection with heat detector systems that trigger an alarm to the OCC when the temperature indicates the presence of fire, and fire-fighting equipment such as fire extinguishers, and hydrant pillars.

  • The drainage system comprises the storm water system, which collects rainwater, and waste water drainage system which discharges water arising from tunnel washing and fire-fighting activities.

  • Traffic control and monitoring systems, together with signs and barriers, enable supervision of traffic flow in tunnels and guide motorists along the way. Automatic Incident Detection (AID) is used to detect incidents and collect traffic data. Closed Circuit Television (CCTV) also provides 100% surveillance coverage in the tunnels.

Lane Use Signs (LUS) and Variable Message Signs (VMS) are placed along and before tunnel entrances to guide motorists and inform them about traffic conditions within the tunnel. To facilitate the closure of tunnel slip roads during maintenance or emergencies, certain tunnels are also equipped with drop down barriers and traffic lights at tunnel entry points.

overview of tunnel safety habits

Safe driving is important at all times; perhaps even more so in a confined space within a tunnel. In addition to the usual safety rules and road etiquette, practice these tunnel safety habits and be mindful of what to do in an emergency:

  • Turn on your headlights and tune your radio to a local FM channel
  • Observe the speed limit
  • Follow the overhead lane use signs. If you see a red “X” above a particular lane, avoid using it
  • If all lanes are marked “X”, do not proceed further. Stop the car, turn off the ignition and head towards the nearest emergency escape route on foot. Stay vigilant for traffic and other road users. Look for the red-and-white or green panelled emergency exits
  • If you are approaching the tunnel and see lanes marked with a red “X”, do not enter the tunnel and look for an alternative route
  • Pay attention to the messages on the electronic signboards, and tune in to local radio stations as the OCC will broadcast emergency messages if any
  • In case of emergencies, you can also find help phones located at escape staircases and fire niche cabinets along the tunnel for you to contact the OCC and emergencies services such as the Singapore Police Force, Traffic Police or Singapore Civil Defence Force.

When inside the road tunnels, follow the lane use signs above each traffic lane. They show if the lane ahead can be used.

Lane is open for use

Green Arrow
The lane is open for use

Lane closure ahead

Flashing Amber Cross
Lane closure ahead
Get ready to change lanes

Lane is closed

Red Cross
Lane is closed to traffic
Do not proceed beyond this sign

In the event of any major obstruction or emergency, red crosses may be lit across all lanes. This indicates that you should not proceed any further.

this is an image of 3 crosses
this is an image of 3 crosses
this is an image of 3 crosses

When red crosses are lit across all lanes, do not proceed further.

For more information, visit the

If you have to evacuate the tunnel on foot:

  • For Woodsville Tunnel and Fort Canning Tunnel, head for the tunnel’s entrance, away from the incident or smoke.
  • For CTE, KPE, MCE tunnels and Sentosa Gateway Tunnel, head for the nearest
    • Emergency escape staircase, which is located every 500m in the tunnel next to the slow lane. The stairs lead to street level; or
    • Pedestrian cross passage door, which is located every 100m in the CTE, KPE and MCE tunnels next to the fast lane. Doors lead to the opposite bound tunnel.
  • For CTE Tunnel, escape staircases and pedestrian cross passage doors are identified by red-and-white stripes and flashing orange lights.
This is an image of an escape staircase

Escape staircase
(every 500m, next to slow lane)

This is an image of a pedestrian cross passage door

Pedestrian cross passage door
(every 100m, next to fast lane)

  • For KPE, MCE and Sentosa Gateway Tunnel, escape staircases and pedestrian cross passage doors (KPE and MCE) are identified by green panels and flashing bluish-white lights.
This is an image of an escape staircase

Escape staircase
(every 500m, next to slow lane)

This is an image of a pedestrian cross passage door

Pedestrian cross passage door
(every 100m, next to fast lane)

Fire hose and extinguishers in fire service cabinets are located every 50m next to the slow lane inside all our road tunnels. Inside these cabinets, you can find:

  1. A fire hose reel
  2. Fire extinguishers
  3. A fire break-glass unit which can be activated to sound an alarm
  4. Emergency SOS phones located every 100m inside alternate fire service cabinets. They connect directly to the LTA Operations Control Centre and can be used to call for help.
Fire Cabinet with fire hose reel, fire extinguisher, fire break-glass unit and emergency SOS phones
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