M81 Motorway Now Open 24 Hours—Free of Charge!

A Faster Route to Kanchanaburi, Cutting Travel Time to Under One Hour and Boosting MICE Travel to the West

Good news for travellers and the MICE sector! The Department of Highways has officially opened the Bang Yai–Kanchanaburi Motorway (M81) for trial use across all toll booths—free of charge, 24 hours a day, every day—starting from 31 October 2025. The trial aims to allow the public and tourists to experience the route ahead of its official launch.

The M81 spans 96 kilometres, connecting Bangkok and its vicinity to Kanchanaburi, passing through Nonthaburi, Nakhon Pathom, and Ratchaburi provinces. It is considered a strategic transportation route that significantly shortens travel time from Bang Yai to Kanchanaburi—from over 2.5 hours to less than 1 hour. The motorway also helps reduce traffic congestion on Kanchanaphisek and Phetkasem Roads, making travel more convenient, faster, and safer.

During the trial period, the maximum speed is limited to 80 km/h for cars, vans, buses, and trucks to ensure safety while systems are still being tested. Trailer trucks are limited to 65 km/h. Bicycles, motorcycles, tricycles, farm vehicles, and human- or animal-powered vehicles are not permitted to use the motorway.

The Department of Highways expects the motorway to be fully operational—with toll collection and a maximum speed of up to 120 km/h—by January 2026. Once officially opened, the route will become a key corridor supporting business travel, meetings, conferences, and tourism for the MICE sector heading to western Thailand.

Source: Department of Highways