A week of overnight closures are needed on one of the key roads in and out of Norwich, as workers race to get the bulk of a £4.6m shake-up finished before the Royal Norfolk Show.

Work on the A1074 Dereham Road at Costessey started last year, with highways bosses saying the changes will cut congestion and improve traffic flow on the busy road.

But the final phases of the work will mean Dereham Road will need to be closed overnight, between Longwater Lane and the A47 roundabout, for a week.

The road will shut from 5pm on Sunday (June 9), reopening at 6am the next day. Then, from Monday, June 10 until Saturday, June 15, it will be closed each night from 7pm until 6am.

That is so the road can be resurfaced between the Longwater Lane junction and Britannia Way. Workers will also be completing a new pedestrian and cycle path and painting all road markings. Traffic lights and pedestrian crossings will also be re-installed.

People who live in Britannia Way and Roundwell Park will still be able to get access and the temporary pedestrian/cycle route will remain open, but other road users will face diversions, with buses suspended.

First buses will not be running any evening buses to either Queen's Hills or the retail park after 5pm on Sunday or from 7pm on Monday to Friday nights.

After these times, all their buses will terminate at the Roundwell Medical Centre on Longwater Lane, with the last buses from Castle Meadow to Queen's Hills leaving at 4.20pm on Sunday and 6.10pm from Monday to Friday.

Buses towards the city will run at the normal times during the closure period, but will start from the Roundwell Medical Centre at the scheduled time.

Excel buses will stop at the Premier Inn near the Showground - those depart from Norwich bus station stand B at 5.10pm, 6.10pm and 7.10pm on Sunday - also at 6.40pm, 7.40pm, 8.40pm and 10.50pm from Monday onwards.

A First spokesman said: "We are sorry for any inconvenience caused due to circumstances beyond our control.

"We regret we are unable to provide an evening service to Queen's Hills as the only alternative route is through Bowthorpe and cannot be accommodated within the timetable."

There will still need to be a few finishing touches after that, including landscaping and a tree planting project later in the year.

Norfolk County Council bosses say they are aiming to have the bulk of the work completed before the Royal Norfolk Show. The show is at the nearby Costessey showground on Wednesday, June 26 and Thursday, June 27.

When the work is finished, it will see the whole of Dereham Road, between the Longwater Lane junction and the A47 widened to four lanes.

The project, which included the diversion of a high pressure gas main which crosses Dereham Road, has also seen drainage in the area improved, including at an area prone to flooding near the bus stop outside the Roundwell medical centre.

The money for the scheme came from developer contributions and £2m from the New Anglia Local Enterprise Partnership's Local Growth Fund.

A spokeswoman for the council said: "We would like to take this opportunity to thank you for your patience during these important improvement works."