The specified value in the corrugated beam guardrail: the anti-blocking block used in expressway is designed to be 4.5 mm, and the actual allowable deviation thickness should not be less than 4.35 mm. However, in some places (such as Shandong and Inner Mongolia), if the acceptance is strict, it must be not less than 4.5 mm thick.
The anti-blocking blocks used in expressway approach roads, first-class highways, second-class highways, provincial roads, county roads and village roads can be thinned accordingly, with 4.25MM, 4MM and 3MM.