SPEED limits as low as 10mph will be imposed when Oxford’s Eastern Bypass is resurfaced.
Transport bosses said daytime commuters would not be affected but others said they would avoid the road while the work was carried out.
The work will take place over six nights, from 8pm to 6am.
It had been due to start on Monday, November 26, but has now been delayed until the New Year.
During the work, drivers will be asked to reduce their speed in the area from the current 50mph limit to between 30mph and 10mph.
The temporary speed limits will be in place on the northbound carriageway of the bypass from Horspath Driftway to the Green Road roundabout and on the southbound carriageway from the roundabout to the stretch of road just north of the Kiln Lane junction.
The county council’s cabinet member for transport Rodney Rose said: “In terms of the roads the council manages, the bypass is probably second only to the A40 when it comes to the large amount of traffic it gets.
“This will be a standard resurfacing scheme.
“A road this well used will be tested electronically every six months to see if repairs are necessary.
“With the work being carried out at night commuters should not be affected.”
Calvin Parker, of Oxford’s Radio Taxis, said the bypass was “choc-a-bloc between 4pm and 7pm”.
But he added: “After 8pm it should not cause too much of a problem. It’s nice to nip there to get to Blackbird Leys and Barton, but the drivers will just have to find another route.”
Oxford-based driving instructor Andrew Usher said: “It is good it’s being resurfaced, but I will just avoid it until it’s done.”
County council spokesman Owen Morton said: “This work has now been rescheduled until after the New Year.
“This is because work currently being carried out on the A34 by the Highways Agency is now expected to last until the end of the month and, as the Eastern Bypass forms part of the diversion route, we can’t get started on the 26 and get the work done before the run-up to Christmas.”