The northbound lane of the Limerick Tunnel is due to re-open tomorrow.
It has been closed since Sunday morning after a truck carrying hay become lodged in the tunnel after failing to heed warning signs indicating height restrictions.
This led to extensive damage to signage, heat detection cables and traffic signals.
25 Specialist contractors have been working round the clock to replace the damaged equipment and an evaluation has since taken place.
Operator Direct Route, says it's "likely to re-open the northbound tunnel" tomorrow morning and "remove the contraflow in the southern tunnel".