Eight people on board were slightly injured when the driver lost control and skidded sideways at Kilometre 59 on the Western Outer Ring Road (Kanchanapisek Road) in Lad Lum Kaew district.
They’d started out from the Rama II Road area in Bangkok.
Pol Lt Colonel Natthapong Thongsri of Bang Khu Luang precinct led the effort to sort out the mess.
Driver Anusorn Lunpat, 41, was unhurt, but eight of his relatives were taken to a nearby hospital.
Anusorn told police he lost control while braking, unprepared for the momentum caused by his heavy load.