A sinkhole that closed the road between two villages will cause traffic congestion and affect medical appointments, residents have said.
Oxfordshire County Council said the A361 between Wardington in Oxfordshire and Chipping Warden in Northamptonshire had been closed since 06:00 GMT on Monday.
The local authority said the sinkhole was likely "to take several weeks or months to fix".
Wardington resident Mark Chivers, who is disabled, said those without any transport "are really quite stuck".
The council said there was likely "scour to the bed of the culvert which had undermined the foundation, but not caused its collapse".
It added that the water levels were "still high".
"The water needs to be removed, the culvert inspected/repaired and the sinkhole filled in to enable the road to be reopened," the council said in a statement.
"We will need to check if any utilities might be affected, which may slow down any repairs.
"As the sinkhole is linked to the structure it is likely to take several weeks or months to fix."
It suggested an alternative route from the A423 Southam Rd to A425 Daventry Road, which is about 27 miles (43km).
The council said that was "an emergency road closure" and any future repair plans would include more new diversionary routes.
Mr Chivers has relied on the bus service between Daventry and Banbury since the summer.
He said the company was now "cutting out Wardington completely" and those without any transport were "really quite stuck".
"I've been trying to book transport to get to a hospital appointment, but that's all oversubscribed.
"There's a lot of people in this village who are disabled like me and some who are elderly as well.
"It's just not possible for all of us to do online food shopping or have people around here to help out."
Maggie Musgrove lives in Northamptonshire's Woodford Halse, which the A361 links with Banbury and Daventry.
"I have heart problems and disability," she said, adding she had upcoming appointments at the Horton General Hospital in Banbury and also at Oxford.
"It's going to take an awful lot of extra time and extra money in fuel [to go to them]."
Mrs Musgrove said she felt "sorry" for the people living in the surrounding villages because traffic was getting "really bad".
She appealed to Stagecoach and the council to "do something as quickly as possible" as the situation might be "putting lives at risk".
Comments