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

Traffic Management at Holyhead Port FAQs


From January 1st, hauliers and commercial drivers who are transporting goods between Great Britain and the EU will be subject to different custom checks. This could lead to some disruption on the trunk road network.

We’ve been working closely with the Welsh Government and local partners, to implement traffic management measures to help manage delays to Europe-bound freight while protecting local roads from disruption.

From January 1st, a temporary contraflow system is to be introduced on the A55 between Junctions 2-4.This will help improve the flow of HGV traffic to the port and to allow HGVs to be stacked on the A55 quickly and safely should the need arise.

  • Heavy Goods Vehicle Traffic travelling to the EU via Holyhead Port

All HGVs will travel via the contraflow towards the port. If they’re turned away from the port they will then be redirected via the contraflow back to the A55 Junction 4 where they will either be held at the A55 stacking area or redirected to other stacking sites as capacity allows.

  • All other traffic travelling on the A55 between Junction 2-4

Traffic will continue along the A55 in a contraflow system. 

contraflow diagram a55

A contraflow system means that traffic will be flowing along lanes in the opposite direction to the norm. As such, when you approach a contraflow system you should reduce your speed in plenty of time. As always, you should adhere to signed speed limits. This is particularly important when contraflow systems are in place because you will be travelling without a safety barrier in between you and the oncoming traffic.

Holyhead Port is the second busiest roll-on roll-off ferry port in the UK and provides a vital link in the supply chain for businesses across Wales, the UK and Ireland. The reasonable worst case scenario published by the UK Government highlights that 40 to 70% of HGVs arriving at ports after the end of the Transition Period could be turned away as they do not have the right documentation. The peak is expected around mid-January.  Delays could also result due to new border checks in Dublin which could delay sailings causing a backlog of HGVs in Holyhead.

This means that traffic management measures are needed to provide sufficient space for HGV traffic travelling to the port and to reduce traffic disruption on the surrounding trunk road network.

The contraflow system will be live from December 28th ready for January 1st. To allow for it to be put in place quickly and safely some traffic management measures are needed in advance. 

There will be times when there are seemingly low levels of HGV traffic travelling to the port on the A55. However, historical data shows that traffic peaks can build up quickly and a new traffic management arrangement cannot be implemented while there is queuing traffic on the A55 to protect the workforce and motorists.

Therefore, a contraflow system needs to be in place in advance to mitigate the risk of significant disruption before it takes place. The potential disruption created from the contraflow system itself is much lower than the disruption and confusion of changing traffic management measures between junctions 2-4 at short notice.

The uncertainty of the traffic situation after the end of transition means that we're utilising all the options available to create a robust traffic management plan. Extending the contraflow to Junction 4 ensures that we have the flexibility to stack additional HGVs if there is insufficient capacity elsewhere. This will help protect local communities and businesses from disruption.

We will continue to monitor and manage the traffic to assess how much capacity is needed on the network and to implement any changes in a safe and efficient manner.


The A55 Junction 3 westbound off slip and on slip, Junction 4 westbound on slip  and Junction 2 westbound off slip will be closed to local traffic for the duration of the contraflow however, all other slip roads will remain open for local traffic. 

Short term slip road closures will be required at Junctions 2, 3 and 4 during the installation of the contraflow from Dec 28th onwards.


The aim of this plan is to ensure there is minimum impact on people living and working in, as well as travelling to / from, Holyhead, as well as providing facilities for outbound HGV drivers.

It is likely there will be delays in the area but we'll be continually monitoring the situation to ensure disruption is kept to a minimum.

Extra checks at the border with the EU will apply to goods, which is why HGVs are affected. Car and foot passengers fall outside this traffic management plan.  In the event that ferries are delayed, the Port Authority has informed us there will be sufficient space to accommodate passenger vehicles.


We will be providing information packs to hauliers via the ferry companies. Traffic management measures will be in place so that HGVs travelling to the port of Holyhead will be directed to the right place. 

Plot 9 Parc Cybi is being prepared as a stacking site from mid-January and negotiations are continuing to use the Roadking truck stop as a site from January 1.

Stacking on the A55 remains the contingency option to use should there be no space on any other site. Traffic management measure will be in place to direct HGVs seamlessly to whichever stacking sites have sufficient capacity.

It is difficult to give an exact date for when the traffic management measures will end, but whilst the plans account for a worst case scenario of up to 6 months, close partnership working between the Welsh Government, the trunk road agent and partner agencies is ongoing to review how much space is required. Welsh Government will seek to modify the traffic management measures or stand down the contraflow as soon as they are confident it is no longer required and safe to be removed. It is expected that most delays will peak from the middle of January. We will be monitoring the situation carefully and providing updates.

Call the Traffic Wales information line
0300 123 1213
Contact us