Highways Department to start collecting tolls on M81 motorway from Jan 16

The Department of Highways will begin collecting tolls on the Bang Yai–Kanchanaburi Motorway (M81) from January 16, after motorists were allowed to use the route free of charge via all eight entry and exit points from October 31.

Piyapong Jiwattanakulphaisarn, director-general of the Department of Highways, said motorists will be required to pay tolls from 00:01 on Friday, January 16, 2026.

He said the department had opened the motorway for a round-the-clock trial run from October 31, with all eight toll plazas and exits available.

Systems ready after installation and testing

Piyapong said the installation and testing of key systems have been completed under BGSR81 Co., Ltd., the private operator of Motorway 81.

These include the toll collection system, the Intelligent Transport System (ITS) for traffic management and control along the route (including the traffic control and command centre), the vehicle weight control system, and the data communications network.

How tolls will be calculated

Tolls will be calculated based on vehicle type and the actual distance travelled, via eight toll plazas:

 Bang Yai, Nakhon Chai Si, Sisa Thong, Nakhon Pathom (East), Nakhon Pathom (West), Tha Maka, Tha Muang and Kanchanaburi.

For example, a four-wheel car travelling from Bang Yai to Nakhon Chai Si will pay 45 baht, while a full trip from Bang Yai to Kanchanaburi will be charged at a maximum of 150 baht.

Payment options: M-Flow or cash

The M81 toll system uses modern technology to improve convenience. At the entry to each toll plaza, vehicles pass through a detection system and automatic number-plate recognition (ALPR) cameras, without having to stop or slow down to collect a ticket. The system records the number plate, matches it at the exit, and calculates tolls based on actual use.

At the exit, drivers can choose one of two payment options:

M-Flow lane (drive-through, barrier-free)

• Automatic payment via a linked method, such as a registered credit/debit card, bank account, or a top-up account such as Easy Pass or M-Pass that is enrolled in M-Flow or upgraded to Easy Pass Plus (Easy Pass+) / M-Pass Plus (M-Pass+); or
• Pay later within seven days via several channels. Users can check outstanding tolls using their vehicle registration number via the MFlowThai app, Line OA @mflowthai, or the mflowthai.com website, then pay via QR code. Payments can also be made at Counter Service at any 7-Eleven branch nationwide, where users can check and pay outstanding amounts 24/7.

Cash lane (stop at the booth)

Drivers stop and pay a cashier at the toll booth.

M-Flow registration and RFID tag service points from Jan 14

Suwichan Suraban, director of the Intercity Motorway Division, said motorists planning to use the M81 are encouraged to register for M-Flow in advance for easier payment, receipts, trip-history searches and other benefits.

Registration is available via the MFlowThai app or mflowthai.com, which the department said has been updated to make data entry simpler.

To make registration more convenient—especially for users in Nonthaburi, Nakhon Pathom, Ratchaburi and Kanchanaburi—the department will open service points for M-Flow registration and RFID tag installation at the rear of the inbound weigh-station area at all eight toll plazas from January 14, 2026. Applicants should bring a national ID card and a copy of the vehicle registration book.

M-Flow members who have not yet installed an RFID tag on their registered vehicles were also encouraged to do so at these service points to improve number-plate reading performance and maximise accuracy.

Speed limits on the M81

The Department of Highways urged motorists to drive safely and follow the maximum speed limits:

• Four-wheel vehicles: up to 120 km/h
• Buses and trucks: up to 100 km/h
• Heavy trucks/tractor units: up to 80 km/h