The longest bridge in the world: the Hong Kong-Zhuhai-Macau Bridge (costing approximately 20 billion dollars) is a marvel in the history of engineering, but in terms of usability, it has become the biggest failure in world history. To date, three years after the bridge was completed, there is hardly any traffic on it.
When the Zhuhai-Hong Kong-Macao Bridge was about to be opened to traffic, the decision-makers suddenly realized a major problem: who will use this bridge?
Vehicles from mainland China cannot use it because license plates from mainland Hong Kong and Macau are not allowed to enter or leave. Vehicles from Hong Kong cannot use it either, because vehicles with Hong Kong license plates are not allowed to drive to China and Macau, and vehicles from Macau cannot use it because Macanese license plates are not allowed to drive to China and Hong Kong.
Only vehicles with license plates from mainland China, Hong Kong, and Macau can use the bridge, and such vehicles are very rare, and those that need to cross the bridge are even rarer.