Traffic congestion is expected to return to Bangkok's main roads Monday as revellers, who went to the countryside, are set for an exodus to the capital, signalling an official end to this year's Songkran holidays.
There are reports from the central province of Ang Thong that traffic has started to build up on Highway 32, which is a segment of the Asian Highway Network.
Stretching from Chai Nat to Ayutthaya, the 150km highway is normally used by revellers to travel back to the capital from northern and central provinces of Thailand.
As of 2pm Sunday, cars going from Sing Buri towards Ayutthaya could move at a speed of only 70-80 kilometres per hour due to the congestion.
Deputy chief of the Royal Thai Police Wirachai Songmetta on Sunday advised the public to start travelling in the morning instead of afternoon or evening, to avoid provincial roads which is likely to see snarled-up traffic in the later hours of the day.
According to Pol Gen Wirachai, cars have already been forced to slow down in the northeastern stretch of Mittraphap road between Pak Chong and Sikhiu district of Nakhon Ratchasima, also known as the Lam Takhong area.
The belt has been notorious for serious traffic congestion during holidays and long weekends.
Highway police have reportedly opened two road diversions along Mittraphap road to ease traffic. They are in Sikhio and Non Sung district, the latter of which is also in Nakhon Ratchasima.
Provincial transport vehicles, such as buses and vans, which are operated by the Transport Co, Ltd, will be plying the highways since 180,000 passengers are expected to travel back to Bangkok each day.
Transport Co chief Jirasak Yaovatsakul said most of the returning passengers will use the company's services between Sunday and Wednesday as Monday is considered the last day off for most businesses in the country.
According to him, the Transport Co had deployed about 8,000 vehicles for trips back to Bangkok during these four days, ramping up its operations by about 2,000 trips daily.
In such cases, the company typically takes the help of the Department of Land Transport to commission extra buses, which were previously checked for safety, for returning passengers.
Mr Jirasak earlier said the company would need at least 300 extra vehicles per day during Songkran.
In a related development, Immigration Division 2 deputy chief Cherngron Rimpadee said about 150,000 inbound Thais and outbound tourists are expected to use Suvarnabhumi Airport per day before festivities come to an official end.
According to him, the number of passengers at the country's largest airport had fallen on Friday and Saturday but is expected to see a sharp spike from Monday until Friday.
It is the last extended holiday weekend for more than three months. At the last weekend in July, the Buddhist Asahna Bucha Day marking the beginning of the Lent period coincides with the birthday of His Majesty King Maha Vajiralongkorn Bodindradebayavarangkun, creating a four-day weekend from Friday, July 27, through Monday, July 30.
"We advise outbound passengers using Suvarnabhumi, Don Mueang and Phuket airports to arrive for checking-in at least three hours before departure," Pol Col Cherngron said.
Urging Thais to use automatic passport scanners to speed up the procedure, the officer said Immigration Division 2 had requested authorities provide more officers to service passengers until Friday.
Meanwhile, National Council for Peace and Order spokeswoman Sirichan Ngathong said 7,067 vehicles have been seized from those driving recklessly and under influence as of Sunday.
According to her, 5,019 of the seized vehicles were motorcycles, while the remaining were cars.
Authorities have confiscated 16,588 driver's licences so far, Col Sirichan added.