Further details of the £90m work to dual part of the A47 in Norfolk have been revealed - with "significant construction" to start early in 2023.
And a string of public exhibitions have been organised where people can learn more about how the work will affect them.
Transport secretary Grant Shapps announced last month that the dualling scheme between Blofield and North Burlingham could go ahead.
National Highways - the government-owned organisation which will build the road - had said work, which will see just over 1.6 miles dualled, would start in October.
The organisation has now confirmed that will be preparatory work and the main construction will get under way early next year.
A new two-lane dual carriageway will be built 70 metres south of the existing road.
Safety improvements will be made to the Yarmouth Road junction, closing the right turn and adding a dedicated lane to join the A47.
A new bridge will cross over the new dual carriageway to connect Blofield and North Burlingham, and take traffic from Blofield toward Great Yarmouth.
The east junction - a notorious crash blackspot - is also being changed, with a new two-tier junction connecting the B1140 South Walsham Road with the B1140 Coxhill Road.
Highways bosses said it is still too early to say what road closures will be needed, but are hopeful disruption can be limited through some of the major elements of the scheme being built off-site.
A spokesman for National Highways said: "Preparatory work at the site will begin from this autumn with significant construction beginning in the new year.
"It’s too early to be specific on road closures but we are building significant elements of the new section of road off-site. This will help to minimise disruption locally.
"Any future closures or diversions will be put in place following consultation with those living and working nearby.
"Their views will help to shape how we plan any roadworks and closures ahead of construction getting under way."
The dualling between Blofield and North Burlingham will be the first of £300m A47 Norfolk projects first earmarked back in 2014.
By the autumn, decisions will have been made on two more major Norfolk A47 schemes.
Where can you find out more?
A series of public exhibitions, where people can ask questions of National Highways officers have been organised, as follows:
Tuesday, August 9: East Anglian Co-op, Norwich Road, Acle (9am to 6pm).
Tuesday, September 27 and Wednesday, September 28: Norwich Caravan and Camping, Yarmouth Road, Blofield (9am to 5pm).
Thursday, September 29: Tesco, Ipswich Road, Norwich (1pm to 8pm).
Thursday, October 6: Sainsbury's, Longwater, New Costessey (1pm to 8pm).
Friday, October 7: Waitrose, Church Lane, Eaton (10am to 6pm).
Saturday, October 8: Tesco, Kingston Road, Dereham (10am to 6pm).
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