Drivers on the A47 are facing a 25-mile diversion for seven weeks for £2.2m worth of road repairs.
The 12-mile single carriageway stretch from the A1075 junction at Dereham to Castle Acre Road, Swaffham, will be closed from this Thursday between 8pm and 6am on weekdays.
During the closure, motorists will have to follow an official diversion which will go via Watton and Bodney along the A1075, B1108 and A1065.
The complete diversion route is about 25 miles long - 13 miles longer than the A47 stretch - and will go between Dereham and Swaffham.
Highways England have told residents the diversion will take approximately 25 minutes to drive.
During the closure, Highways England, which sent letters to 2,064 addresses about the work, will update the road signs and line markings, repair the road surface, renew weather detection equipment and clear vegetation.
Councillors and road safety campaigners - who want that section of the A47 dualled - have said the work which starts this week is essential.
Last week a male passenger died after two lorries crashed at Scarning, between the A1075 and A1065.
It was the third fatality on that stretch of road in four months.
Norfolk county councillor Martin Wilby, chairman of the A47 Alliance group - pushing for the complete dualling of the road from Lowestoft to Peterborough - said: 'Highways England have realised the need for improvements.'
He said A47 dualling would not happen overnight.
A Dereham Town Council spokesman said: 'The town council has been calling for maintenance to be carried out for some time and welcomes the planned works for the A47.'
Mid Norfolk MP George Freeman said he would be holding a site visit with Highways England at the Draytonhall Lane junction near Scarning next month 'to stress that small works are not enough on this stretch of road'.
He said: 'Full dualling is needed to improve safety and ensure Norfolk has the transport network it requires in the 21st century.'
A Highways England spokesman said: 'The number of people hurt on the A47 is reducing, but we are determined to do more to improve safety.
'We are taking forward six major improvements on the A47, valued at £300m... we have a comprehensive maintenance and renewals programme – of which this vital resurfacing work is part - that is helping to keep the A47 operating safely.'
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