Roads are designed to ensure safe and smooth traffic for vehicles with certain specifications. In principle, vehicles that do not meet size and weight requirements are not allowed to be on the road, because they can potentially damage the road’s structure or disrupt traffic.
However, road administrators are empowered to give permission to the vehicles that exceed the size or weight regulations to use the road, but only if the road administrator acknowledges that there are no alternatives after examining the vehicle’s structure and the cargo. In these cases, the road administrator will put certain conditions in place to protect the road structure and prevent potential dangers to road users.

■On general roads

General limit (upper limit) of vehicles according to Article 3.1, Vehicle Size and Weight Restriction

■On expressways

Road administrators are authorized to permit the drivers of vehicles that exceed the size or weight regulations to use the road, but only after the road administrator examines the vehicle’s structure and the cargo and determines that there are no alternatives. In these cases, the road administrator will put certain conditions in place to protect the road structure and to prevent any potential dangers to other road users. Road fatigue, which is caused by vehicle traffic that is over the weight or size regulations, has a significant effect on road structures and pavement. In order to utilize our road stock effectively in the future, it is important to ensure that road structures are properly maintained now.

1. Instructive enforcement
Drivers are told to pull over at "instruction stations", where vehicle weights and sizes are measured. If the vehicle exceeds the size or weight regulation, the drivers are ordered or warned to reduce the weight and size of the vehicle by splitting the cargo.

2. Weigh-in-motion (WIM)
A WIM device automatically measures a vehicle’s gross weight as the vehicle drive over a measurement site. If the vehicle is over the weight regulations, it then determines if the overweight vehicle has a permit by accessing the database. Based on the results, repeated violators will be given an instructive warning.

■Weigh-in-motion