The government has backtracked on a new rule that came into effect Wednesday barring people from travelling in the rear space, or trays, of pickup trucks following fierce criticism from the public.
The regulation will now only be enforced after the Songkran festival.
Deputy national police chief Detnarong Sutthichanbancha said the government has decided to offer a reprieve, though no date has been fixed yet for enforcement of the new regulation.
During the Songkran period, officers will only give verbal warnings to passengers who sit on pickup bed rails, he said.
People can continue to sit in pickup trays and the government has not set a maximum number of passengers, Pol Gen Detnarong said.
However, he insisted police will still enforce the law on fastening seat belts, particularly for passengers in commuter vans.
Pol Gen Detnarong said only a few arrests were made for traffic violations in relation to seat belts in Bangkok Wednesday. No details about the total fines levied were available, but those who were fined for sitting in pickup trays cannot reclaim the amount now enforcement has been postponed, he said.
The about-turn came in the evening after the rule against people travelling in the trays and the rear areas of two-door pickups came under heavy criticism during the day, particularly on social media.
The measure is part of toughened traffic safety measures under Section 44 of the interim charter, which was enforced nationwide starting Wednesday.
Critics say low- and middle-income people from rural areas need to use pickup trucks to get back home during the festival and most accidents do not happen because they sit in the back of them.
A Chumphon police officer is being investigated after he posted a Facebook message criticising the controversial measure.
Pol Lt Col Akarat Hoongnam, an inspector at Salui police station in Tha Sae district of Chumpon, said the law should not cause problems for people and it is important to enforce it at all social levels. "If high-society people or the rich are allowed to make the laws, they will not care about the plight of the poor," he said.
Instead of barring people from riding in pickup trays, there should be a greater focus on enforcing speed limits, he said.
However, Chumphon police commander Sonthichai Awathanakulthep has instructed Pol Lt Col Akarat to explain his actions, according to deputy Chumphon police commander Wimol Phitakburapha.
Pol Col Wimol said if he is found to have committed an offence, a committee will be formed to take disciplinary action against him.
He said police are duty-bound to enforce laws in line with government policy, and they should not oppose them.
A Facebook posting by a police officer in the deep South complained the people who come up with such traffic laws are those who spend their time in air-conditioned rooms who do not care about the poor.
"How would 10 people be able to go to work together in the front space of a vehicle? How could we [the police] fight back against bandits who shoot at us?" he said, referring to the fact that police also sit in the back of pickups.
In Khon Kaen's Muang district, more than 100 people were arrested within two hours after police set up a checkpoint on Wednesday.
The traffic violators were fined 200 baht each. They included those who failed to fasten their seat belts and people travelling in pickup beds.
Muang Khon Kaen police superintendent Noppadol Petsut said the fines were low and efforts had been made to educate drivers. Some received only verbal warnings.
Those found sitting in pickup trays heading to the city centre will be put in police vans which will later drop them off in town, he said.
Bandit Donnang, a 65-year-old driver of a pickup, was arrested and fined 200 baht for carrying his relatives in his vehicle's tray. They were heading to a merit-making ceremony.
He said even though he agreed with the safety drive, he wanted authorities to ease the measure.
People in rural areas do not have enough money to pay for public transport so they just travel together in a pickup as a group to save on transportation costs, Mr Bandit said.
Another Khon Kaen resident, Thongchai Monstri, said he had no objection to forcing people to fasten seat belts, but was confused about the law on travelling in pickup trucks.
"In ordinary life, people in rural areas travel in pickups together to work or contact civil services in the city centre," Mr Thongchai said. "I want the government to review the law."
In Suphan Buri, Ampon Pensut, a 46-year-old resident of Muang district, said she disagreed with the pickup tray travel ban.
She said she has children and nephews and nieces to drive around and the law would make travel for her family more difficult.
Phanom Duang-lamai, a 44-year-old construction contractor, said he usually uses his pickup to carry construction materials and workers and the law spelt trouble for him.
In Chiang Mai, Pol Col Thapanapong Chairangsri, chief of the provincial traffic police, said no arrests were made of people travelling in pickup trays on the first day of the law's enforcement. Officers emphasised a public relations campaign and only gave out warnings, he said.
A man showed up at a checkpoint at Wat Lok Molee on Manee Nopparat Road in Muang district and complained about the strict traffic measure.
He said police should offer a reprieve for people riding in the back space of pickups, adding he needs to take his children to school. The rule might prompt people to protest against Prime Minister Prayut Chan-o-Cha in large numbers, the man said.
Speaking after a meeting of agencies dealing with traffic safety in the morning, national assistant police chief Pol Lt Gen Wittaya Prayongpan called on the public to buckle up and wear crash helmets when travelling to cut the chances of loss of life.