Mysterious underground movements have caused a road to shatter as if hit by an earthquake.
Repair work to a section of the B4069 near Lyneham in Wiltshire could cost millions to repair, with huge cracks in the tarmac.
Wiltshire Council say the road has been closed since February 17 - but some drivers are still trying to use it according to police.
The earthquake-like damage has been caused by unexplained underground movements which will now be investigated.
Local residents claim the subsidence has been getting worse over the last year and a landslip was inevitable.
Wiltshire Council said it is now waiting for a report from geotechnical specialists before taking further action.
Dr Mark McClelland, Wiltshire Council cabinet member for transport, told BBC Radio Wiltshire: "It could costs hundreds of thousands or up into the millions [to fix].
"There is significant damage to the road. It could be up to 12 months in total. It's not something that can be resolved in a matter of days or weeks."
Dr McClelland added in some places the road had 'buckled' up to four feet, and descriptions of it looking like an earthquake were accurate.
He added: "The underlying ground has slipped and we need to understand why that has happened.
"The police have been very clear that it's very dangerous for motorists to ignore signage."
The remarkable damage is also affecting local business, with local pubs like the Peterborough Arms suffering huge losses in bookings since the closure.
