Islanders are being warned of further delays as "the most disruptive" part of the St Mary's Roundabout scheme begins in just over a week.
The next phase of the controversial works are expected to last for more than a month, according to the Isle of Wight Council.
From October 12 to November 23, St Mary's Roundabout will be removed and replaced with traffic lights.
As part of plans, overnight closures will be put in place.
Diversions set to come into place.
Hunnyhill will also shut to all through traffic (except buses), to allow for a new bus lane and signal-controlled pedestrian crossing to be built.
The council insists the project - which is now entering its final phases - is on schedule.
Councillor Ian Ward, Cabinet member for transport and infrastructure, said:
"Despite some challenges, not least the coronavirus pandemic, we remain on course to complete this project on schedule, thanks, in no small measure, to the co-operation and understanding of residents.
"We are extremely grateful for this and as we embark on the concluding — and potentially most disruptive — phase of work, we would once again ask for your continued support.
"Further delays will be inevitable as drivers adjust to the different traffic arrangements, so if you can avoid the area and find an alternative route, please do so if possible.
"By the end of November, we'll have a much improved junction with greater capacity and reduced congestion, improved pedestrian and cycling connections to the hospital and improvements to bus journey reliability between Newport and Cowes."
What is happening in the next phase?
According to the council, a new traffic light junction will allow vehicles coming from Cowes, and wanting to travel west to Yarmouth, to turn right at the junction with Forest Road.
Work from October 12 to October 26.
The local authority says overnight closures will be in place to allow for cabling to be installed for temporary lights, until new permanent ones become operational.
This work will be undertaken over two nights on October 10 and 11 between 8pm and 6am.
Works from October 26 to November 23
During this time, a southbound diversion will be in place via the Dodnor estate and Riverway, and the northbound diversion will be via Hunnyhill.
The council insists resident access will remain on Hunnyhill, despite the closure from October 12. Residents will be able to enter the road from the southern end (at its junction with Foxes Road and Hunnycross Way).
How St Mary's will work from November 23 to December 18
Access to Whitesmith Road will be via Albany Road during this time.
The final phase of the work to lay out Parkhurst Road as a cul-de-sac (with no through access) will be completed between November 23 and December 18.