A nineteen million pound improvement project is due to start on the A47 at Postwick near Norwich.
Government funding was granted 5 years ago, but it's been subject to a number of legal challenges.
The work is intended to release land for up for 1,600 homes and make it easier to build a planned northern bypass round the city.
Police say the accident on the A47 near Norwich has now been cleared and the road is open again.
Police say a lorry, a tractor and a tanker were involved in a crash which has closed the A47 Eastbound just outside Norwich. The incident took place on the section of the road heading towards Harford Bridges just after Thickthorn roundabout.
Norfolk Police say there do not appear to be any major injuries but the road will be closed for some time while investigations are carried out.
Traffic is being diverted off the A47 and Norfolk Constabulary would urge motorists to try to find alternative routes at this time.
The A47 Southern bypass has been blocked East bound by a crash between the Thickthorn roundabout and A140 junction.
A £19m scheme to improve a major road junction in Norwich is on course to start next month after ministers released the funding.
The work on the Postwick junction of the A47 aims to increase capacity.
Norfolk County Council said the improvements would allow nearby business and housing developments to go ahead, creating five thousand jobs and unlocking £82m of private investment.
Three people have died in a crash on the A47 at East Winch.
The crash involved a lorry and a car. All three people in the car died at the scene. The lorry driver suffered minor injuries.
The Acle Straight has now been closed in both directions between Acle and Great Yarmouth due to the accident at the Halvergate turn.
The Transport Minister, Stephen Hammond has travelled along the A47 from Great Yarmouth to Peterborough to see for himself the problems with the road.
Business leaders and MPs are calling for more investment to improve the troubled road.
The Transport Minister Stephen Hammond has been in Norfolk to see first-hand the problems with the A47.
He took a trip from Great Yarmouth to Norwich while he was here and Kate Prout went to meet him. You can watch her extended interview here.
The Transport Minister Stephen Hammond, is visiting the region today to see for himself the challenges facing businesses and motorists who rely on the A47.
The Minister will travel along the key route between Great Yarmouth and Peterborough as business leaders make a case for greater investment.
He will also meet with local MPs and listen to views on the road, to see what can be done to tackle the problems that drivers face.
The visit comes after the a Government announcement on he 20th August that the Department for Transport would undertake a feasibility study on the A47.