MOTORISTS face major delays on one of the region's busiest routes this week as bridge replacement work is stepped up.

The Highways Agency has advised drivers to leave extra time for journeys on the A66 between Teesside and Darlington as lane closures could cause tailbacks.

Work is continuing on the replacement of Surtees Bridge at Thornaby, resulting in further delays for motorists from today until next weekend.

So far, work has been carried out during off-peak times only. However, from today, some lanes will be closed in both directions.

On Friday night, the whole section of the A66 between Stockton and Thornaby will be closed, with diversions in place.

From today until Friday, the outside lane will be shut in both directions between 9.30am and 3.30pm. But tomorrow, the outside lane will also be shut in both directions from 7.30pm to 6.30am.

Traffic will be diverted off the A66 on Friday night and directed through Stockton and Thornaby, when the dual carriageway at Thornaby is closed to traffic in both directions from 7.30pm to 6.30am on Saturday.

Heading east, motorists will be asked to leave the A66 at the new link road to Stockton and Ingleby Barwick, travel along Bridge Road and Mandale Road, before picking the A66 up at the Middlesbrough Road junction in Thornaby.

The road will be open on Saturday, but a contraflow will be in operation in both directions for 24 hours, resulting in narrow lanes.

The slip road from the A66 to Thornaby Road will also be closed until further notice.

Arun Sahni, project leader for the Highways Agency, said: "A lot of work has gone into getting us to this position, but now the work of balancing the needs of the programme with the requirements of drivers starts.

"The Surtees Bridge carries on average 55,000 vehicles a day, so we are working to keep two lanes of traffic running in both directions through the morning and evening peak periods, but with a restricted speed limit of 30mph.

"At other times of the day, we may have to reduce lanes further and occasionally have full closures overnight.

"This is to make sure drivers and our workforce are safe throughout the works period.

"We would ask all road-users to approach this section of the A66 with care over the next 18 months and be ready to obey any warning and diversion signs."

Work on the bridge, which will cost £14.3m, is expected to last until September of next year.