HGVs travelling north and west benefit from the expected six-minute journey time through the tunnel.

The tunnel was first suggested in the 1990s after a number of transportation and engineering studies and was included in the Dublin City Development Plan 1999 – 2005.

The contract was managed by Dublin City Council and supervised by Brown & Root, a unit of Halliburton.

The final project cost was brought to €752 million by land acquisition, design, insurance, legal and other services, plus supervision by Brown & Root.

Construction commenced in June 2001 and the tunnel was originally due to open in 2005 after an elapsed time of 43 months.

The southern section, at Fairview, is 500 m long while the northern cut and cover channel from Whitehall Church to Shantalla extends over 1500 m. This work was undertaken by the Mowlem and Irishenco units of the consortium.

Both bored sections were initiated from a shaft 33 m deep and 57 m in diameter created at Collins Avenue by Mowlem in a joint venture with Intrafor of France.

From here, the Tunnel boring machines (TBM), managed by Nishimatsu, were sent north through open clay and south through hard limestone.

The machine, designed by Herrenknecht of Germany, was 156 m long, 12 m in diameter and was delivered to Dublin port in 105 parts carried by three ships, taking one week to unload.

A similar process was followed northwards by the 60 m long TBM-2 "Meghan" boring from Collins Avenue to Whitehall Church, first creating the southbound carriageway.

A particular challenge was faced near the southern portals where the tunnel passes under the Dublin to Belfast railway, a line that also carries suburban and commuter services.

The railway was constructed on an elevated embankment made up of soft materials resting on alluvial deposits of sand and silt.

A new entrance and exit for the Dublin port was constructed including a new bridge over the Tolka River that connects to the toll plaza and southern portals.

The service contract provided for operation, maintenance, safety, traffic management and toll collection.

GSM telephone and FM radio coverage is carried into the tunnel with break-in facilities over public broadcasts in the event of an emergency.

The hauliers cited unreasonable traffic congestion on the M50, especially during the imminent widening of the northern section while IBEC and the Port Company were concerned about restrictions on the free movement of goods.

The Sunday Independent ran a story on 12 November 2006 revealing the ban came into force soon after the Tunnel opened.

The then Taoiseach Bertie Ahern reportedly put pressure on the council to abandon their phased approach and initiate the ban in one go.

One company located south of the Liffey, Marine Terminals Ltd, considered taking legal action against the Council if it went ahead with banning trucks from the city.

This was because a ban would force the company to use the tunnel, which would mean crossing the privately owned and operated East-link toll bridge, incurring a €4.80 charge each way.

Proponents of the chosen design argued that it made the best economic sense and that it would be able to accommodate most heavy vehicles with only a minor percentage having to use the surface road network.

In its submission to the public inquiry, the Irish Road Haulage Association did not raise the issue of the operating height of the Port Tunnel.

The most recent event was held on 26 March 2017, when over 2,400 runners participated in the "Underground Run", with proceeds going to the homeless charity Focus Ireland.