Can the traffic police give a reasonable explanation for the reason why Hangzhou Xiasha Bridge prohibits semi-trailers?

Let me help you answer it from the perspective of an old driver.

Answer the question first: the slope is too big.

Xiasha Bridge is a steel structure bridge with 4 beams and 5 arches, and the approach slope is too large, especially in the direction of Xiaoshan on the south bank. Most semi-trailers and heavy trucks have large tonnage and need to slow down and downshift when encountering steep slopes, while private cars are generally light and do not need to slow down when crossing the bridge. Therefore, it is easy to take a sudden stop during driving. Xiasha Bridge has frequent accidents all the year round, especially in bad weather.

Then the problem comes again. Why is the design slope of Xiasha Bridge so large? The reason is related to the geological reasons on both sides of Qiantang River in this area. The quicksand impacts the soft foundation and the tide changes frequently, so the existing structural scheme is considered in the design.

But further investigation is that the bridge was built too early. The design and construction of Xiasha Bridge was still in the era of 199X, and the planning at that time was the Unicom Bridge of Hangzhou Ring Expressway. Note that it is the "Ring Expressway". Therefore, the key point is that the main target vehicle of Xiasha Bridge design is the private car of Hangzhou citizens. Even if there is a big truck, it is occasionally decorated.

However, after the completion of the bridge, because of its location advantage, it quickly became the main line on the north-south artery of the Yangtze River Delta, and a large number of large-tonnage trucks cut corners here. Xiasha Bridge is one of the bridges with the largest annual traffic volume on Qiantang River. This exposes the problems of the original design scheme.

In order to solve this problem, the authorities have taken speed limit measures. The original design speed was 120km/h, but now we can only drive110km/h. But this still can't alleviate the speed difference caused by steep slope.

Therefore, it is also helpless to ban semi-trailers. You know, this bridge is not designed for big trucks. If large trucks want to be unimpeded, they can only appeal to the authorities to build another truck-only bridge.