>>512067908
>why didn't they build tunnels?
Because all of China's infrastructure and architecture is about puffing their chests out and appearing advanced, almost always at the expense of safety and functionality. This decision was 50/50% determined by how impressive it could look on social media, and how quick and cheap it can be done.

In the west, we are massively over cautious when developing roads and bridges, buildings etc. which is why nothing gets done without an insane amount of bureaucracy and taxpayers money, but the end result werks 99% of the time. China on the other hand build with their eyes not their brains, paying the consequences either immediately or in a few decades