Skip to main content
Traffic Wales information line 0300 123 1213
The Welsh Government’s traffic information service for motorways and trunk roads in Wales

Driving Safely in Wales' Motorway & Trunk Road Tunnels

A55 Penmaenbach tunnel aerial view

If your journey takes you through one of the Motorway and Trunk Road Tunnels in Wales, it’s important to know what to do in the unlikely event of an incident.

Travelling through the tunnels will not normally present any danger. However, in the event of an incident, due to the enclosed nature of a tunnel you will need to pay extra attention to the safety of yourself, your passengers and other tunnel users.

Tunnels provide additional challenges to the public and the emergency services in the event of an incident. A number of safety features and procedures have been developed to help the public to safely evacuate the tunnel or allow emergency services access to manage incidents should they occur.

This page provides you with information about the tunnels and advice on how to avoid becoming involved in a tunnel incident and how to look after your own and others’ safety.

Welsh tunnel map showing A55, M4 and A40 tunnels

There are 6 Motorway and Trunk Road Tunnels in Wales.

A55 Conwy Tunnel

Built in 1991, this immersed tube tunnel was the first of its kind in the UK. At 1060m, the tunnel is the longest road tunnel in Wales.

A55 Penmaenbach Tunnel

Penmaenbach Tunnel opened in 1989 to carry westbound traffic. It is 658 metres in length and was blasted through the hillside.

A55 Penmaenbach Headland Tunnel

Built in 1932 Penmaenbach Headland tunnel was cut into the cliff by hand. It replaced the original coach road built by Telford in the early 19th century.

A55 Pen-y-Clip Tunnel

This tunnel was opened in 1994 after three-and-a-half years boring and shoring work that removed more than 103,000 cubic metres of granite from the headland.

M4 Brynglas Tunnel

The 360m twin bore, two lane holes, opened in 1967, are significant because they were the first tunnels to be built on the British motorway network.

A40 Gibraltar Tunnel

Built in 1969, these are a pair of bored tunnels, carrying the A40 through Gibraltar Hill.

Safety features of tunnel illustration

 

Tunnel lighting icon

TUNNEL LIGHTING

Lighting to improve visibility inside the tunnel.

ventilation system icon

VENTILATION SYSTEMS

To clear pollution and control heat and smoke to assist evacuation during a fire incident.

Fire extinguisher icon

FIRE EXTINGUISHERS

Emergency panels are equipped with fire extinguishers.

wayfinders icon

WAYFINDERS

Identify direction and distance to emergency exits for pedestrians from a tunnel.

cctv camera icon

CCTV

CCTV are there to help the Traffic Management Centres monitor tunnel operations and detect incidents.

tunnel public address system icon

PUBLIC ADDRESS

Speakers are located throughout the tunnel. In the event of an incident listen to any announcements and follow all instructions given.

emergency sos phone icon

EMERGENCY PANELS (SOS)

Emergency panels are marked by illuminated signs. They are equipped with fire extinguishers and free call SOS phones linked to the Traffic Management centre.

emergency access door signs icon

EMERGENCY ACCESS DOORS

Emergency access doors are installed in some tunnels to allow emergency services access to an emergency from the non-affected tunnel bore. Wherever possible  evacuation should be via the tunnel portals.

lane controll signal icon

LANE CONTROL SIGNALS

Indicates which lanes are open or closed. Observe and obey at all times.

 

tunnel safety icon speed limit

Observe all speed limits on the approaches to and through the Tunnel – caution these may change.

tunnel safety icon fuel gauge

Check you have sufficient fuel for your journey.

tunnel safety icon lane signals

Observe and obey signs and signals - Never use a lane displaying a red cross.

tunnel safety icon dipped headlights

Use dipped headlights. Remove your sunglasses if in use.

tunnel safety icon hazard warning lights

If there is smoke or fire ahead of you in the tunnel, do not enter. Pull over into the left-hand lane, stop and switch on your hazard warning lights.

 

tunnel safety icon do not stop sign

Do not stop unless in case of an emergency.

tunnel safety icon space between cars

Keep a safe distance between you and the vehicle in front. Vehicles should leave at least a 2 second gap and large goods vehicle a 4 second gap.

tunnel safety icon no u-turn

Do not turn or reverse unless instructed by a Police or Traffic Officer.

tunnel safety icon no smoking

Do not discard cigarettes within the confines of the tunnel.

 

tunnel safety icon space between cars

Keep your distance, even if you are moving slowly or have stopped - always leave a gap of at least 5 metres between you and the vehicle in front (an average car length).

tunnel safety icon switch off igniton

Switch off engine if stationary for more than one minute.

tunnel safety icon hazard warning lights

Switch on Hazard warning lights when approaching congestion in accordance with the Highway Code.

tunnel safety icon public address system

Listen to messages broadcast over the public address system and follow the instructions given by the tunnel operator at all times.

 

tunnel safety icon hazard warning lights

Switch on Hazard warning lights.

tunnel safety icon switch off igniton

Stop your vehicle as close to the left-hand side as possible and switch off the engine. Leave the key in the ignition.

tunnel safety icon exit car on left

Be aware of approaching traffic from front or rear. If possible exit your vehicle from the left hand door. Passengers should do likewise. If you are unable to exit the vehicle for any reason dial 999. The tunnels are closely monitored and assistance will be provided as soon as possible.

tunnel safety icon sos phones

Call for help from a telephone at the SOS emergency points located every 100 metres along the tunnel. Be aware of other vehicles. DO NOT cross the carriageway.

tunnel safety icon information sign

Listen to messages over the public address system and follow the instructions given by the tunnel operator.

tunnel safety icon spanner

Do not attempt any repairs whilst in the tunnel.

 

tunnel safety icon no enter

If there is smoke or fire ahead of you in the tunnel, do not enter. Pull over into the left-hand lane, stop and switch on your hazard warning lights.
 

tunnel safety icon vehicle fire exit

If there is smoke or fire ahead of you in the tunnel, then pull over to the left-hand side and stop. Switch off the engine, leave the key in the ignition and evacuate the vehicle. Leave the tunnel on foot, following the signed evacuation route towards the tunnel portal through which you drove to enter the tunnel. Once outside the tunnel, wait at the signed evacuation point for further assistance.

tunnel safety icon fire in rear view mirror

If you observe smoke or a fire behind you once in the tunnel, continue to drive out of the tunnel and do not re-enter.

tunnel safety icon exit signs

If your vehicle is on fire then drive out of the tunnel if possible. If this is not possible, then pull over to the left side and switch off the engine. Leave the key in the ignition in case the emergency services need to move your vehicle. Evacuate immediately. Leave the tunnel following the signed evacuation route towards the nearest tunnel portal. Once outside the tunnel wait at the signed evacuation point for assistance.

tunnel safety icon sos phones

Call for help at the SOS phones located at the evacuation point outside the tunnel.

tunnel safety icon information sign

Listen to any messages over the public address system and follow the instructions given by the tunnel operator.

tunnel safety icon fire extinguisher

There are fire extinguishers next to every emergency panel within the tunnels.

 


Call the Traffic Wales information line
0300 123 1213
Contact us