Drivers are being warned they face hold-ups on the A47 Swaffham Bypass as work is carried out to repair a collapsed manhole.
Temporary traffic lights have been installed on the eastbound section between the Norwich Road roundabout and Sporle Road junction.
BT is carrying out remedial works and drivers are advised, due to the safety risks, one lane will be closed and traffic signals are in place until the repairs are completed.
Highways Agency project manager Andy Shilliday said: 'We are working with BT to ensure this repair is fixed as soon as possible and anticipate it to be completed by tomorrow afternoon.
'We have been able to keep the road open using traffic signals but we ask drivers to allow a little extra time to travel along this route as there could be delays.'
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