Works to the bridge over the River Lune as part of the Heysham M6 Link Road have ground to a halt.
Road builders Costain said that structural work to the Lune West Bridge stopped several weeks ago due to technical problems.
The project got into difficulties when engineers attempted to lower the bridge deck down onto the bridge piers.
During one of the initial jacking operations the loads on a number of the temporary jacks increased to a level greater than expected.
Costain said that at this stage the operation was halted whilst it was investigated.
A spokesman said: “This is a technically challenging phase that requires a number of sequenced operations to transfer the load around the structural members until it rests in its final position and takes its final shape.
“During one of these operations a load transfer occurred that was not predicted.
“It was at this stage the operation was stopped for further analysis. Engineers have been busy revising the methodology to enable the bridge to be safely lowered in a timely manner.
“This has been developed and is currently undergoing an independent check by structural engineers, after which we are confident that the works will recommence.”