Major traffic delays caused by construction of a multi-million junction on the edge of Norwich have sparked immediate changes to the project - and an apology from council bosses.

Norfolk County Council admitted that the opening of a new slip road at the Postwick Hub, on the A47 to the east of Norwich, had caused 'significant delays'.

The balance of traffic flows at the Peachman Way roundabout was 'worse than expected', so the council has been forced to make a string of changes to try to stop a repeat.

The steps the council is taking include:

• Putting traffic control on the Peachman Way/Broadland Way roundabout for the morning as well as the evening peak. This will be manually controlled to be as responsive as possible to traffic build-up.

• Putting signs up at the Plumstead Road/Green Lane junction to warn of potential delays at the Peachman Way/Broadland Way roundabout.

• Changing the planned works programme to now keep the old bridge open during peak hours.

The old bridge had been scheduled for a full closure for up to eight weeks for essential maintenance and upgrading.

It will now remain open for use even when the new bridge, work on which was delayed last night because of wet weather, is open tomorrow morning.

The council says keeping the old bridge open will allow traffic from the Great Yarmouth direction to avoid the Postwick Hub access roads and will help to relieve any additional pressure on the Peachman Way roundabout at peak times.

A council spokesman said: 'Having both bridges open will also give greater flexibility within the junction, and Norfolk County Council will continue to monitor traffic flows and take further steps to reduce delays if necessary.

'The maintenance and upgrading work on the old bridge will be carried out under more limited traffic management with off-peak lane closures. Any full closures – for resurfacing for example – will take place overnight.'

The A47 will be closed at Postwick again tonight, but the diversion routes will be short, using the junction slip roads.

Construction work on the £27m junction, at the eastern end of the A47 Southern bypass, started in May last year. Drivers have faced months of disruption, with road closures and diversions.

The council says the junction will release land for 1,600 homes and unlock some £80m of private investment, potentially paving the way for 5,000 jobs.

But protestors criticised it as an over-engineered gateway to the controversial Norwich Northern Distributor Road.

There were legal challenges to planning consent and a public inquiry, before work could start.