A new provision has made it an offence for learner drivers to be unaccompanied in cars.
The 'Clancy Amendment' of the Road Traffic (Amendment) Act means the owner of a vehicle, who knowingly allows an unaccompanied learner or unlicensed person to drive, could face prosecution.
From today, anyone who allows a learner driver use their vehicle faces serious penalties, including stiff fines or even jail time.
Their vehicle could be detained by the Gardaí, or they could be fined.
The law was named for Geraldine and Louise Clancy, who died in a road crash involving an unaccompanied learner driver in 2015.
Noel Clancy - whose wife and daughter died - said: "We are very pleased that this new law is coming into effect at last.
Moyagh Murdock, chief executive of the Road Safety Authority (RSA) added:
"A learner permit is not a licence. Learners have not passed a driving test. As inexperienced and unqualified drivers they're a risk to themselves and other road users if allowed to drive unsupervised."
To support the introduction of the new law, the RSA collaborated with Mr Clancy to develop a new public awareness campaign.
