Drivers in Northern Ireland may have to wait even longer than expected for MoT test backlogs to clear, BBC News NI can reveal.
The Department for Infrastructure (DfI) said a new test centre at Hydebank, in south Belfast, due to open in 2022, is now scheduled to open later this year.
A new test centre at Mallusk, in County Antrim, scheduled to open in 2024, is now planned for 2025.
A Driver and Vehicle Agency (DVA) report attributed delays in the development of new testing centres to the Covid-19 pandemic, the supply of materials and problems with the company contracted to provide testing equipment.
The DVA said that the two new centres will provide the capacity to test more than 200,000 additional vehicles per year.
'Impact on delays'
The newly-appointed chair of the Northern Ireland Assembly's Infrastructure Committee told BBC News NI that she "will be raising MoT testing with the minister as soon as possible".
"There has been a number of issues facing MoT testing with long delays caused by various reasons," said the DUP's Deborah Erskine.
"Without access to new MoT test centres, it will further have an impact on delays."
A DfI spokesperson said that Sinn Féin minister John O'Dowd "is currently being briefed on the key issues for the department and is aware staff in MoT centres are working seven days a week to reduce vehicle test waiting times".
County Antrim-based mechanic Darren Fleck warned that for people "not as on the ball" who rely on a DVA reminder letter for their MoT test, the booking system can be quite stressful.
He said many of his customers think they have to keep phoning for tests, rather than booking online.
"Booking MoTs so far in advance is OK if you are a petrolhead who keeps ahead of all of the scheduled maintenance and listens to the news and hears that you have to book and MoT three or four months in advance," he said.
But there are always appointments available for those who are "well clued up" and know when to look online, he added.
"You just need to be a bit more flexible about where you can take the car to."
The new test centre at Hydebank was granted planning permission in 2019.
Construction was due to start in 2020, with a planned completion date of 2022.
DVA reports show that the opening date was later revised to March 2023 and again to the end of 2023.
All of these targets were missed.
Planning permission for the test centre at Mallusk was approved in December 2022 and the centre was scheduled to open in 2024.
A report published by the DVA in July 2023 noted that targets for key milestones in the development of this site were also missed.
In its annual reports, the DVA has attributed the delays in part to "contractual problems" with Worldwide Environmental Products, the company it had contracted to supply testing equipment for its centres.
The DVA took issue with the work being carried out by the company and tried to terminate the contact.
The company, however, challenged this termination in court and won, forcing the DVA to maintain the contract.
In a statement, the company said it "has worked with DVA on the implementation of our MoT equipment at the new test centre at Hydebank according to our contract and an agreed upon schedule for implementation".
Alliance Party infrastructure spokesperson David Honeyford said that delays in the MoT process "from obtaining an appointment to now construction of new centres, has now become a long-running saga".
"Now the executive is restored, urgent action is needed to deliver a fit-for-purpose service," he told BBC News NI.
"There is no excuse to be still stuck in this quagmire years after Covid and technology issues."