THOUSANDS of drivers have been passing along a busy Exeter road unaware they were also crossing an ancient bridge.
The structure, under Holloway Street, was originally built as a bridge and dates from before the construction of Exeter Cathedral.
It came to light when experts moved in to repair a collapsed sewer.
Contractor May Gurney had been preparing to undertake the work but repairs were delayed because the site is immediately adjacent to the ancient masonry arch structure, which is a scheduled monument, lying deep under the highway. The structure has been inspected by Devon County Council engineers.
The arch, which is maintained by Devon County Council, was found to have suffered some damage during the sewer leak with some of the mortar joints being washed out.
Councillor Stuart Hughes, Devon County Council cabinet member for Highways and Transportation, said the structure would now be preserved.
He said: "Thousands of people pass over this ancient structure each day unaware of its existence, but as a Scheduled Monument we have a duty to ensure it is maintained and protected.
"Our bridge team has lent its expertise on this issue, liaising with English Heritage to get the appropriate consent for the repair work in around a week, when it would normally take at least 12 weeks.
"English Heritage has been extremely supportive in recognising this as an emergency and that work is required urgently.
"We have resolved these issues as quickly as possible to enable South West Water and its contractor to carry out its work and keep traffic delays to a minimum."
Councillor Jill Owen, Devon County Councillor for Priory and St Leonard's, said the work was proving disruptive.
She said: "I hope that this necessary work will continue to be treated as urgent.
"Not only is it causing hold-ups for the traffic, but nearby residents are being badly affected by the extra traffic passing very close to their houses.
"I am grateful to all involved that they are working as quickly as possible."