Hertfordshire County Council said that checks carried out after installation had identified concerns about several of the prefabricated beams. It has been working closely with contractor Tilbury Douglas to establish the extent of the defects and how best to resolve the issue.
Tests and assessments were conducted and it was concluded that all the prefabricated beams will be replaced. New beams and a deck will be installed after the defective beams have been removed.
The bridge is being built as part of the A602 scheme, which includes a series of improvements between Stevenage and Ware to bring the road up to current safety standards and improve reliability of journey times.
Traffic will continue to run on the current A602 while the works are carried out to the new bridge.
Phil Bibby, executive member for highways and transport at Hertfordshire County Council, said: “We are pleased that the solution has been agreed, to ensure that the road and bridge are constructed as intended. We welcome the patience of the community and road users until the road opens in summer 2023.”