Probation Department chief Pol Col Narat Sawettanan said there were 3,471 drunk driving cases this year, compared to 4,059 cases in 2015.
The cases have been ruled by courts and the drunk drivers have been put on probation after they were fined, Narat said.
This year, the government invoked Article 44 of the interim charter to empower the authorities to impound vehicles when their owners or drivers were found having drunk.