The £200m dualling of another five-and-a-half miles of the A47 in Norfolk will begin next year, after the government said the scheme can go ahead.
Transport secretary Grant Shapps has agreed to grant development consent for the section between Easton and North Tuddenham, with bosses at National Highways targeting an opening in winter 2025.
It follows Mr Shapps decision in June to permit the dualling of just over 1.6 miles of the same road, one of Norfolk's key routes, in a £90m scheme between Blofield and North Burlingham.
The Easton to North Tuddenham scheme, which will cost £200m, includes two new junctions at the Wood Lane/Berry's Lane and Norwich Road/Blind Lane junctions, along with the removal of Easton roundabout.
There would also be four new bridges and road closures.
Mr Shapps agreed with the recommendation by planning inspector Adrian Hunter.
Martin Wilby, chair of the A47 Alliance and Norfolk County Council cabinet member for highways, infrastructure and transport, said: “Dualling of the A47 here will improve safety, congestion, connectivity and journey times along the route, bringing not only benefits for residents but a boost for businesses from Lowestoft to Peterborough and everywhere in-between."
Chris Griffin, programme leader for National Highways in the East Region, said: "Our work here will reduce congestion, improve journey times and, most importantly, make the road safer. That is great news for local people and those who regularly work or travel in the area."
The decision means two of three schemes announced in 2014, when then prime minister David Cameron pledged £300m would be spent on the A47, have now got permission.
In addition to the dualling schemes at Easton to North Tuddenham and Blofield to North Burlingham, the third project would see changes to the Thickthorn junction on the edge of Norwich.
Mr Shapps has until September 12 to make a decision over that scheme.
There has been frustration at the amount of time it has taken to reach the point where work will begin on the three projects, given the money was announced so long ago.
Despite getting final approval, there remains a threat to the Blofield to North Burlingham scheme.
Lawyers acting on behalf of Dr Andrew Boswell, a former Green county and city councillor, have launched a legal challenge to the scheme, which could end up in the High Court.
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