More than 5,700 driving tests have been cancelled in Northern Ireland because of industrial action by examiners.
Some vehicle test centre staff have been on strike since last month
The action in support of a pay claim by members of the Northern Ireland Public Service Alliance union began in May.
Chris Gray from the ABBA school of motoring in Belfast said something needed to be done to resolve the dispute soon.
"The driving test situation in Northern Ireland is nearly at meltdown with only a few centres actually still open," he said.
"It is a very, very serious situation. Something has to be done to resolve it as soon as possible."
The figure of 5,791 cancelled tests was given in a reply to a parliamentary question from shadow Northern Ireland Secretary David Liddington.
Meanwhile on Friday, Department of Environment planning officers in Enniskillen, County Fermanagh, began indefinite selective strike action.
Nipsa General Secretary John Corey said the union had sympathy for those affected by the strike.
"I would ask the public to recognise that the workers who have taken strike action have done so as a last resort.
"They have been denied a fair pay increase for over two years, they do not take the action lightly" he said.
"We want to negotiate a resolution of this dispute, but unfortunately the ministry and senior management have failed to do so."
Martin Woods, Customer Relations Manager of the Driver Vehicle Test Agency, said staff had been redeployed at the centres which are still open.
He said that more than 300 driving tests were taking place each week.
"We will try to meet individual customers' needs.
"Where we are aware of a particular difficulty we will try to address that. It is important to keep in contact with the managers in the centres that are open."
On Tuesday, Nipsa warned a temporary exemption on MoT tests for private vehicle owners in Northern Ireland would compromise road safety.
Most of the vehicle examiners in the Driver and Vehicle Testing Agency are currently on strike.
The exemption was laid down in the House of Commons on Tuesday in response to a major backlog in vehicle inspections caused by the ongoing industrial action.
When the emergency legislation is passed, anyone with a vehicle up for renewal can drive without a test certificate.
It is believed the law will not go through until later in the summer.
Nipsa members began strike action last month at nine centres across Northern Ireland.
It is part of a wider dispute over pay, which began last December.
DVTA centres in Armagh, Craigavon, Lisburn, and Newry are unstaffed and no testing is taking place.
No testing is taking place at Belfast, Londonderry, Larne and Newtownards test centres, although some staff are providing an information service.
About 6,000 MoT tests a week, as well as practical driving examinations, are being affected by the industrial action.
Nipsa has been involved in strike action since December over what they said was the government's refusal to give civil service staff any cost of living increases in rates of pay since April last year.
The government has imposed a pay package which will add 3.67% to the wage bill of the Northern Ireland Civil Service.
However, union officials say that was part of a pre-agreed increment and takes no account of the rise in the cost of living.