The measure – aimed at curbing drunk driving and lowering Thailand’s near-world record road fatalities – was published in the Royal Gazette on Wednesday as the 21st ministerial regulation under the Land Transport Act 1979.

Police testing motorists for alcohol consumption are authorised to file a charge of driving under the influence if blood alcohol concentration (BAC) is above 20mg/100ml or the equivalent.

The same charge can also be filed if the motorist is under 20, cannot produce a driver’s licence, is carrying a temporary, suspended or revoked licence, or has a licence to operate a vehicle of a type other than the one being driven and for which substitutions are not permitted.

In other cases, drunk-driving charges await motorists who exceed the legal BAC limit of 50mg/100ml.