Plans to link the Port Tunnel will the southern half of the M50 are being considered.
The project would cost 4 billion euro.
The ambitious 11 kilometre underground motorway would be more than twice as long as the port tunnel allowing motorists heading southbound to continue on to the M50.
If built its hoped the tunnel would ease traffic congestion and enable more trucks to avoid the city centre.
The idea is part of the city's development plans.
A full report and recommendation on the project will be considered at a meeting of the city council on May 5th.
