A47 dualling in Norfolk and Cambridgeshire revealed
Plans for £300m of improvements to one of the eastern region's main roads have been unveiled by Highways England.
The A47, which connects East Anglia to the Midlands, will see three sections of the 115-mile stretch between Great Yarmouth and Peterborough dualled.
Highways England said improvements would also be made to several junctions and roundabouts.
It said the project, to start in March 2020, would "improve users journey times and safety".
Local politicians and users have called for the road, which is a strategic route for the East of England, to be widened at key points.
Philip Davie, of Highways England, said: "We have listened to the publics' views and these have helped shape and inform our approach to our proposed schemes.
"Work now continues, adding detail to the design for each of the dualling and junction improvements, and on planning how we will deliver them in a way that keeps traffic moving," he added.
The first completion date of the six projects is expected from March 2021, the Highways Agency said.
Martin Wilby, chairman of the A47 Alliance, said the work needed to start as soon as possible.
He added: "They will make a massive difference, making journey times more consistent along the A47."
- A47 North Tuddenham and Easton - upgrade to dual carriageway along existing route
- A47 Blofield to North Burlingham - new stretch of dual carriageway built to the south of the existing A47
- A47 Thickthorn Interchange with A11 - new direct links to the A47 eastbound and westbound
- A47 Great Yarmouth junctions (formerly A12) - Vauxhall roundabout enlarged with an extended bridge and new slip road. The Gapton roundabout will be widened
- A47 Wansford to Sutton - A1 junction at Wansford dualled west of Peterborough, plus a dedicated slip road from A1 southbound to A47 eastbound
- A47 Guyhirn - roundabout enlarged and River Nene Bridge widened to three lanes