City Hall has called on people in the capital to stop using private vehicles to help tackle the choking smog that has worsened since Wednesday.
Hazardous levels of airborne particles have been reported in several areas of Bangkok since last week.
The move came after the Pollution Control Department (PCD) reported the airborne particulate matter on Wednesday surged above the safety limit of 50 microgrammes per cubic metre (µcg) over a 24-hour average in many areas of Bangkok since last week, a level which could endanger people's health.
As of yesterday morning, levels of particulate matter of 2.5 microns or less in diameter (PM 2.5) were measured at 84 µcg along Intharaphithak Road in Thon Buri district; 68 µcg in Rama IV Road in Pathumwan district; 66 µcg in Bang Na district; 65 µcg along Lat Phrao Road and in Wang Thonglang district; and 51 65 µcg on Phaya Thai Road in Ratchathewi district.
The levels of dust particles in the first five areas were higher than those measured on Wednesday. The voluntary vehicle ban is part of City Hall's six-year action plan to improve air quality by zeroing-in on the root causes of air pollution. The plan is being co-drafted by City Hall and the PCD, said Bangkok Metropolitan Administration (BMA) city clerk Patarut Tardaranon.
Under the action plan for 2017-2023, Mr Patarut said besides urging motorists not to use private vehicles, other issues included traffic management and an increase in the number of bicycle lanes. Besides the action plan, City Hall claimed to have rolled out several measures to cope with the current dust situation.
Mr Patarut said the public were encouraged to use public transport instead of their private vehicles while motorists were urged to turn off their engines after parking. Inspections would be conducted on vehicles emitting black smoke, particularly those belonging to City Hall officials, while lorry drivers would be advised to cover their cargoes with canvas.
Aside from the use of vehicles, Mr Patarut said the measures against air pollution also focused on construction work.
Contractors were required to fence off their construction sites with structures covered with cloth to prevent dust while vehicles' wheels must be cleaned before departing from building sites.
Teams would be dispatched to inspect construction sites, he said. In addition, rubbish burning must be prohibited outdoors while street food vendors are encouraged to use clean cooking stoves. Green zoness and the frequency of street cleaning in the city would be increased with more trees grown along roads across the capital, he said.