Why doesn't Hanle Expressway allow large trucks to pass?

From today, the Hanle Expressway will be repaired and large trucks will be banned. From today to July 25, Hanle Expressway will carry out road maintenance, and some sections will be subject to one-way and two-way traffic, and large trucks are prohibited from passing. The reporter saw at the scene that the road administration staff had set up a corresponding isolation belt at the Laoyukou interchange to guide the trucks to get off the highway in an orderly manner. The road administration staff told the reporter that because they made propaganda in advance, many truck drivers may know this situation and make a detour in advance. Some drivers, after learning the situation today, also took a detour under the guidance of the staff. The reporter learned that at present, there are 30-40 km mountain roads in the Western Han Expressway that are one-way and two-way traffic, and also remind the majority of drivers and passengers to slow down and travel safely.