Work described by council officers as 'critical' in the building of the controversial Norwich Northern Distributor Road has been completed two months ahead of schedule.

Foundation piles for the bridge that will carry the dual carriageway over the Norwich to Sheringham railway in Rackheath have been installed, with work which had been earmarked to last until just before Christmas already finished.

Fifty king post piles, to create a temporary protective wall alongside the railway, and 90 bridge foundation piles have been installed in overnight working at the site of the bridge.

The work started in early August and had to be carried out at night when no trains ran.

Chris Sedman, project director for main contractor Balfour Beatty said: 'This is a key bridge on the route of the NDR, and working close to the railways has presented considerable challenges.

'Getting this overnight piling finished in just eight weeks, with no disruption to rail services, is a real achievement.

'All this has been achieved while maintaining close control and monitoring of noise from the site. Piling can generate high noise levels, so before work started in August properties most at risk were hand-delivered letters which included ways of raising noise issues with the NDR team, but we received very few comments or complaints.'

The next stages on the rail bridge will be the construction of the base and abutment walls, all leading to the main beams going on around Easter next year.

The NDR will stretch from the A47 at Postwick to the A1067 Fakenham Road.

Supporters say it will boost business and cut rat-running, but critics say it will lead to swathes of countryside being concreted over.

There was a budget of £178.9m for the 12.5 mile route, but the council acknowledges the project could exceed that figure.