Note 02 · Underground
Tunnels of Ireland
Three major tunnels cross water in the country: one under the harbour in Dublin, one under the Lee in Cork, and one under the Shannon in Limerick. Here is how to use them without forgetting the height restriction, the toll or the way out.
The three tunnels
There are only a few long tunnels in the Republic, but they often fall on the fastest route between two places. They differ a great deal in their tolls, their height limits and the facilities beside them.
Dublin Port Tunnel
This tunnel runs from Dublin Port under the bay to the M1 at the M50 junction on the northern side. It is the most direct way from the port to the motorway, and it is often quicker than going around the city. Construction began in 2001 and it opened in 2006. It is one of the longest urban tunnels in Europe.
There is a height limit in the tunnel that affects tall vehicles, and the height is shown on gantries above the lanes before the entrance. If you have a van, a roof box, a boat or equipment on your car, check the height stated on the sign and on the official site before you enter. If you are in any doubt, go around.
Jack Lynch Tunnel, Cork
This tunnel runs under the Lee in Cork, on the N40, and connects the city north and south without going through the centre. There is no toll. It was built as an immersed tube tunnel: precast sections were sunk into a channel in the riverbed and covered over. It opened in 1999.
Limerick Tunnel
The tunnel runs under the Shannon south of Limerick, on the N18, and links the M18 with the roads to the west and south. It is tolled. When it opened it took heavy traffic out of the town's streets and made the journey to Galway much shorter.
Height, dimensions and barriers
The height limit is not the same in the two tolled tunnels. The limit is written on the gantries before the entrance, and the lowest number on any of them is the one that applies to you. One more thing: there is no free space in a tunnel. If a car stops, all the traffic behind has to get past it safely, and the tunnel operators are watching the screens.
Check before you set off. A roof box, an awning or a bicycle on the back of the car changes the height easily. If the limit on the sign leaves you only a few centimetres, going around is the safe choice.
How a tunnel is used
- Reduce speed to the limit on the sign, and keep your dipped lights on if required.
- Do not change lane inside the tunnel except where the signs allow it.
- Keep more space between you and the car in front than you would outside.
- If you are carrying fuel, gas or flammable material, follow the advice on the sign before the entrance.
- Come out smoothly; the speed limit is often raised just after the exit.
When you do not want the tunnel
If you want to avoid the toll there are other routes, but they are often much slower and run through residential streets. In Dublin the M50 itself is the way around, although it has its own toll. You can look at both options along with the shape of the day before you decide.
It is worth knowing that prices and rules change with the day and the direction. This site does not state specific tolls; check the official site for the current rates.
Questions about this note
Short answers to the things people ask most.
Can a tall car use the Dublin Port Tunnel?
There is a height limit and it must be checked in advance. If your car or load is above the limit, you must use another route.
Do I have to stop to pay a toll?
Not in every case. The M50 has a barrier-free system and a toll can be paid online or through an account. Details are in the note on road tolls.
Is there a footpath in the tunnel?
No. Pedestrians, bicycles and slow vehicles may not enter a motorway tunnel.
What do I do if my car stops in the tunnel?
Switch on the hazard lights, stay in the car if you can, and use the emergency telephone on the wall. Follow the operator's instructions.
Related notes
Further reading that goes with this material.
