Further emergency work needs to take place on Torridge Bridge near Bideford.
Work to replace damaged expansion joint and cover plates at the west end of Torridge Bridge has been completed.
However, recent inspections carried out on the structure have revealed that further emergency work will be needed on another section.
A Devon County Council spokesman said: “It was originally planned that the cover plates at the east end of the bridge would be replaced later this year but they have reached a critical condition which now requires immediate replacement.
“This work is underway with the 20mph speed restriction remaining in force and temporary two-way traffic lights are in place.
“This work is expected to take around three weeks and is due to be completed by Friday, May 4.
“The expansion joint at the east abutment will still need to be replaced later this year.”