It is the latest version of the famous Thai smile – motorcycle policemen with a bright red goofy grin painted onto their white anti-pollution masks.

For the first week of the year – and longer if people seem to be smiling back – highway policemen in Thailand will wear the masks “to lift the mood of motorists,” according to police officials.

“For our highway policemen, we have the policy that the police must be friendly and smiling all the time, but the problem is, when we’re tired, it’s hard to keep smiling,” said Colonel Somyos Promnim, the Highway Police commander.

It has been a rough year in Thailand, with revolving governments, restless mobs and a weeklong takeover of Bangkok’s airports that frightened away tourists from the country that keeps on calling itself “The Land of Smiles.”

“They have to put on a mask because a smile doesn’t come naturally anymore,” said Ammar Siamwalla, an economist who keeps a close eye on the mores of his countrymen. “Normally people smile. You don’t have to put on a smiley mask.