Dublin’s busiest rail line is getting an upgrade at a cost of about 1bn

Iarnród Éireann is planning a transformation to the line between Dublin Connolly and Malahide.

A new plan, named FourNorth will allow more capacity, more services and more reliability by proposing the provision of additional tracks alongside the existing two-track railway between Dublin Connolly and Malahide.

The plans aim to remove critical bottlenecks and unlocking additional capacity. This will allow trains to move more smoothly through the corridor, improving times and making better use of the existing network.

The construction of two additional tracks will require extensive modernisation of the ten stations along the route.

FourNorth will seek to address the challenge of a critical bottleneck on this section by delivering three core improvements:

• Capacity - Increased capacity, creating space for more trains and more passengers.
• Frequency - Faster, more predictable journeys including at peak hours.
• Reliability - Fewer delays, wait times and disruptions including less maintenance closures through greater operational flexibility.

The government say FourNorth will deliver wide-ranging benefits, including:

Iarnród Éireann plans to begin public engagement in late 2026, giving passengers the opportunity to have their say.

Consultation will take place at key stages and will include online resources, mailed information, public events and hosted sessions - designed to provide clear project updates and meaningful opportunities for feedback for all stakeholders.

Minister for Transport Darragh O’Brien said he welcomed progress being made on design on the FourNorth project.

"The rail line between Dublin Connolly and Malahide is one of the busiest on the island, and track capacity is a major constraint on frequency and capacity upgrades," he said.

"The Four North project will not only unlock future growth and support additional DART, Commuter and Enterprise services, but will also enhance reliability and enable speed improvements for the services already operating today."