Up to 30,000 people on their third or subsequent provisional licence have never sat a driving test.
In some cases, learners have been driving on for over 30 years without ever holding a full licence.
As The Irish Times reports, the figures from the Road Safety Authority span the period from 1994 to now.
While those on third or subsequent learner permits must show evidence of applying for a test, there is no legal requirement for them to actually sit the test.
Learner permit holders on their first or second learner permit were excluded from the analysis as they are likely to be completing the required lessons.
According to the RSA, 28,570 drivers were on a third or subsequent learner permit first issued between 2018 and 2009.
The RSA added that a significant cohort of drivers who secured their first learner permit before 2008 and who still have not got a full licence may not have sat a test.
At the start of this year, about 420 drivers a month failed to show up for their driving tests, around 3 per cent of the total tests.
More than a decade ago, the Road Safety Strategy (2013-2020) included an action to end the loophole that allows learner drivers to continuously renew their licence without having to sit a test.