The cabinet on Tuesday approved an amendment to the traffic law that makes it easier to prosecute young people who drink and drive.
Under the amendment, the authorities can prosecute drivers aged under 20 found to have an alcohol level exceeding 20mg per 100ml of blood, less than half the current minimum of 50mg.
Speaking after the cabinet meeting at Government House, Athisit Chainuwat, assistant spokesman for the Prime Minister's Office, said punitive measures would be brought against drivers aged under 20 if an alcohol test showed they had more than 20mg of alcohol.
Drivers older than 20 who do not have a full driver's licence or hold a temporary one will also be subject to the 20-mg limit.
The 50-mg limit applies to those older than 20 but possess a full licence.
The amendment would effectively alter the ministerial regulation on a driver's alcohol level under the Land Traffic Act as proposed by the Royal Thai Police earlier, Col Athisit said.
Government spokesman Lt Gen Sansern Kaewkamnerd said the cabinet also approved a Transport Ministry recommendation to abandon an earlier proposal that would have punished learner drivers.
The move follows a public outcry at the measures which required learner drivers to pay for an additional 15 hours of driving lessons before taking their test.