Devon County Council is appealing for witnesses after motorists hitting Denham Bridge closed what is the main route out of the Bere peninsula towards Plymouth.
The bridge near Bere Alston has been closed for safety reasons after being damaged in two separate incidents last week.
The parapet of the Grade II Listed bridge has been dislodged after being struck by two vehicles.
Devon County Council is appealing for anybody who witnessed these incidents and is able to provide details of the vehicles to please contact its customer service centre on 0345 155 1004.
The county council is currently assessing the extent of the damage and is discussing the issue with conservation officers.
Until these initial investigations are carried out it’s impossible to say exactly how long the bridge and the road will be closed for, but it is expected to be weeks as specialist scaffold is needed in order to undertake repair work safely.
Once repairs have been carried out, the county council says it will consider ways to improve protecting the structure.