M82 opens free route above Rama II’s ‘seven-generation road’

Motorists travelling between Bangkok and southern Thailand will gain a 25-kilometre toll-free route above Rama II Road when the full Bang Khun Thian–Ekkachai–Ban Phaeo stretch of Motorway No 82 opens for trial use at 10am on Friday (August 28, 2026).

The Department of Highways will add the 16.4km Ekkachai–Ban Phaeo section to the existing elevated link from Bang Khun Thian. Trial operations will run around the clock without tolls.

Motorists will be able to enter M82 from the Southern Kanchanaphisek Ring Road at Bang Khun Thian Interchange and travel above Rama II Road to Ban Phaeo. From there, they can rejoin Highway 35 and continue towards Wang Manao Interchange in Pak Tho district, Ratchaburi, for onward travel to southern provinces.

The department said the motorway was intended to ease chronic congestion on Rama II Road and improve passenger and freight transport. It also expects the route to support trade, investment and tourism in Samut Sakhon, Samut Songkhram, Ratchaburi, Phetchaburi, Prachuap Khiri Khan and other southern provinces.

Four access points available from opening day

Motorists will be able to enter and leave the elevated motorway at four locations:

• Phanthai Norasing
• Mahachai 1
• Mahachai 2
• Ban Phaeo

The Samut Sakhon 1 and Samut Sakhon 2 access points will remain closed because construction has not been completed. The Department of Highways aims to finish the remaining civil works by the end of 2026.

Temporary limits imposed during trial service

Civil construction on the elevated motorway is about 98% complete, but some civil work and motorway-standard safety systems remain unfinished.

The Department of Highways said the structure had passed load testing conducted with the Engineering Institute of Thailand under Royal Patronage. The assessment found that the structure met the required standards and was ready to open on August 28.

Temporary restrictions will nevertheless apply during the trial period:

• Passenger cars must not exceed 80km/h.
• Trucks and buses must not exceed 65km/h.
• Motorcycles of all engine sizes, bicycles, three-wheeled vehicles, pedestrians and carts of all kinds are prohibited from using the elevated motorway.

Vehicles not permitted on M82 must continue to use the ground-level route where applicable. Motorists using the motorway have been asked to obey traffic signs and instructions from officials.

Why Rama II became the ‘road of seven generations’

Rama II Road, officially Highway 35, is one of the main corridors linking Bangkok with Samut Sakhon, Samut Songkhram and southern Thailand. Its reputation for seemingly endless construction dates back more than half a century.

Construction began in 1970, and the original two-lane road opened in 1973. It was widened to four lanes between 1989 and 1994, expanded to as many as 14 lanes in some areas between 1996 and 2000, and upgraded again between Bang Khun Thian and the Samut Sakhon Industrial Estate from 2001 to 2003. Further widening towards Wang Manao followed between 2006 and 2009, before elevated-road and M82 construction began in 2018.

The nickname “road of seven generations” does not refer to a single construction contract that has run continuously since 1970. It reflects repeated waves of widening, repairs and new elevated structures that have returned work zones, lane restrictions and congestion to the corridor across successive generations.

Repeated accidents involving construction equipment and structures above active traffic have deepened that notoriety.

A five-tonne concrete beam fell from a U-turn bridge in Samut Sakhon in July 2022, killing two people and injuring five. In November 2024, a crane and concrete beam collapsed at an M82 construction site, killing six workers and injuring nine.

Another launching gantry collapsed on the Ekkachai–Ban Phaeo section of M82 on January 15, 2026, falling onto two passing vehicles. Two people were killed and two were injured, prompting the Department of Highways to suspend work on the affected section while an investigation and safety review were conducted.

The combination of recurring construction, prolonged bottlenecks, shifting completion schedules and fatal incidents led the route to become widely known both as the “road of seven generations” and the “road of never-ending construction”.

Toll collection scheduled to begin in 2029

The Department of Highways has set out the following timetable for completing and fully operating M82:

• 2026: Complete the remaining 2% of civil works.
• 2027: Begin installing toll-collection and intelligent traffic-control systems, with the work expected to take about two years.
• 2029: Open the motorway for full official operation and begin collecting tolls.

Under the current schedule, the August 28 opening will remain a toll-free trial service before full operations begin.

Motorists can obtain traffic information or report highway emergencies around the clock through the Department of Highways hotline on 1586.