TWEED Shire council has threatened to excavate part of Cudgera Creek Rd if motorists don't stop moving a concrete barrier blocking a closed-off area.
A section of the road has been closed since the March 2017 floods and the section blocked off by the barriers is unstable, the council has warned.
The council's manager for infrastructure delivery Tim Mackney warned moving the 2.5-tonne concrete barriers could result in disaster.
He said they may have to resort to excavating the area so motorists physically cannot drive through it if they continue to move the barrier, which was most recently tampered with this week.
"Motorists are unaware of the danger they are putting themselves, their passengers and other road users in,” Mr Mackney said.
"While it may appear that one lane is still trafficable, the concrete pipe under the road is fractured and in imminent danger of collapse. It also has been displaced and the road above has failed.
"If the road collapses under the weight of a vehicle, the person responsible for pushing the barriers out of the way could face serious criminal charges.
"But, the graver consequence would be the fate of the people in the vehicle.
"We cannot say this strongly enough. The closed section of road could slip at any time.”
Mr Mackney said the council's insurers would not accept claims resulting from motorists travelling on the closed section of the road.
He said motorists' insurance policies would also become void if they ignored the closure.
"If the concrete barriers are moved again, we will excavate the section of road so vehicles cannot cross it,” Mr Mackney said.
"But we do not want to take this action as it will cause further damage and add more time and cost to its repair.”
Mr Mackney said the process of accessing Natural Disaster Relief and Recovery Arrangements prolonged the time it took to repair roads like Cudgera Creek.
Tenders to repair this section of road close today and the council is expected to award the contract at its March meeting.
The council has written to residents to warn them it is illegal to tamper with road signs and barriers and an offence to travel beyond a 'road closed' sign.