Devon County Council said the majority of repair work to Bideford Long Bridge will take place under the bridge, though there may be some road closures.
Work to refurbish Bideford Long Bridge is due to start on Monday.
The majority of the work on the listed structure will take place under the bridge, which will only require the pedestrian footway on the north side of the bridge to be closed.
However, some lane closures with temporary traffic lights may be needed outside of peak times during the 18-week scheme, in order to accommodate unloading of scaffolding and materials.
The refurbishment will involve repointing of the bridge piers, although a section of the bridge deck will also be resurfaced, which will be carried out under a road closure planned for mid-November.
This is expected to take a week to complete and advanced warning signs will be placed out on site to notify drivers.
Councillor Stuart Hughes, Devon County Council cabinet member for highway management, said: “Every effort will be made to minimise disruption while this essential maintenance work is undertaken on this Grade 1 listed structure.
“It’s important that resurfacing is also carried out during this scheme as it will prevent water from damaging the structure in future.”
Councillor Linda Hellyer, DCC councillor for Bideford East, added: “I am really pleased that Devon County Council is carrying out this work to preserve our historic and strategic Bideford Longbridge.
“Any disruption should be minimal, and this work will help to protect our bridge for many years to come.”
Work will be carried out by South West Highways.