What does the "three super" car on the expressway mean?

The "three overloads" on the expressway refer to speeding, overcrowding and overloading.

Another kind of "three super" refers to special transportation, that is, the transportation of super-high, super-wide and super-long articles. Three supercars generally need special vehicles for transportation, such as low-chassis semi-trailers, concave vehicles and large tractors with a load of less than 300 tons. Usually, the items to be transported are large mechanical equipment and machines.