Ministry of land transportation announced to all trucks to avoid parking on shoulder. In case of emergency, please put emergency light or sign to warn other trucks to avoid crash or accident, which may occur while parking on shoulder.
Trucks should have 2 pieces of sign as truck equipment, which are warning triangle signs, safety cones, etc. to put at the front and back of truck. The sign should be place 50 meter from the truck, which is a perfect distance to warn other truck to notice and can stop the truck properly.
The specification of triangle sign is 50 cm. long on each side. For safety cones, the height should be more than 50 cm. with base diameter more than 28 cm.
Trucks, which do not have equipment as follow, will be fine for 50,000 THB and drivers who do not put the sign when parking on shoulder will be fine for 5,000 THB and will be responsible for any accidents that occurred by parking on the shoulder.
See link below for more detail.