Mae Hong Son — Highway 108, the route linking Chiang Mai–Hot–Mae Sariang–Mae Hong Son, has been thrown into chaos after heavy rain brought flash floods that eroded the abutments of a Bailey bridge and swept away a bridge pier. Authorities have announced a complete closure, prohibiting all vehicle types from crossing. Only motorcycles and pedestrians are permitted to pass. As a result, trucks, tour buses, and scheduled passenger buses have been stranded on both sides of the bridge since the middle of the night.
The Huai Pong Subdistrict Administrative Organization, Mueang Mae Hong Son District, was notified by local residents that sustained heavy rainfall caused flash flooding from the Huai Pong stream at around 10 p.m. on 17 August, eroding the abutments of the Bailey bridge that connects Highway 108 between Mueang District and Khun Yuam District.
The force of the current began to impact the bridge abutments and also caused damage to the road surface at the approach and exit of the temporary bridge. Village leaders were compelled to survey the site and close the Bailey bridge as a precaution, as floodwaters were still surging through violently and posed a danger to users.
Subsequently, Acting Sub-Lieutenant Yodphet Khamsaengdi, Director of the Mae Hong Son Highway District, ordered officials to inspect the structural integrity of the temporary bridge, which has been in use for more than two years following the major flood disaster of 2024. The bridge serves as the main crossing on Highway 108 on the Mae Hong Son–Mae Sariang–Hot route, and no alternative detour to another point can be constructed.
A preliminary inspection found that the main bridge pier had been so severely undercut by the current that it affected the original foundation, and both abutments on either side of the bridge have also begun to subside, posing a significant risk. Officials were therefore compelled to announce a strict closure prohibiting all vehicle types from crossing, with passage permitted only for pedestrians and motorcyclists. Authorities are urgently coordinating with the Phichit Road Construction Center to request support in the form of equipment and heavy machinery to address the problem.
The closure of the Huai Pong Bailey bridge has had a direct impact on road users. Trucks and scheduled passenger buses operating on both the Mae Hong Son–Chiang Mai route and the Mae Hong Son–Bangkok route are unable to pass until the road construction team completes repairs, and no timeline can yet be estimated.
What can be done at present is to have all vehicle types wait on both sides of the bridge so that goods and passengers can be transferred to the other side only. The critical concern is the volume of floodwater from the ongoing rainfall, as any further rain would inevitably place additional and severe strain on the entire Bailey bridge structure.
Meanwhile, the Mae Hong Son Provincial Office of Disaster Prevention and Mitigation has issued warnings via the mobile alert system to residents in Mueang District and Khun Yuam District, urging them to remain vigilant about the impact of heavy rainfall and to prepare for possible evacuation.
