Work to dual the last single carriageway section of the A11 through Norfolk and Suffolk is due to start next year, the government has revealed.
The government plans to transform the nine-mile stretch of the road between Barton Mills and Thetford in a scheme set to cost £131m.
Roads minister Mike Penning made the announcement on Tuesday.
Business leaders and local MP believe the dualled road will help boost the economy of the area.
Matthew Hancock, Conservative MP for West Suffolk, said: "I am delighted that the Department of Transport has announced it will dual the A11 within the next financial year.
"Everyone across East Anglia knows how important this stretch of road is.
"Thanks to the planned improvements, millions of people will get home more quickly and safely than before."