The team coordinating the €100m Dunkettle Interchange project in Cork said it hopes to appoint the contractor before the end of June.
Works involve the removal of the central roundabout and traffic lights at the junction near the Jack Lynch Tunnel which handles up to 100,000 vehicles a day.
The interchange connects the M8 Dublin Rd and N25 Waterford Rd with the N8 Lower Glanmire Rd which serves the city centre, and the N40 South Ring Rd.
Transport Infrastructure Ireland said it is one of the most complex roads projects ever undertaken, and will be on par with the redesign of Dublin’s Red Cow interchange.
The Cork scheme, which is expected to take four years to deliver, will enable traffic to move freely north-south as well as east-west.
Meanwhile, remedial resurfacing works will take place on the westbound slip-road off the N40 South Ring Rd to the Sarsfield Rd roundabout overnight on Monday, and possibly Tuesday.
The slip-road will close from 9pm on both evenings.
Plans are also being finalised to resurface a small section of the roundabout itself, and a section of the link road westwards towards the Bandon Rd roundabout.