There are very few instances of the neighboring countries that drive on the opposite side of the road. A rare example is shared border between China and former British colony Hong Kong or China and former Portuguese colony Macau.
Both Macau and Hong Kong have retained the left side drive rule, while the Chinese drive on the right side. This conflict presents an unusual engineering dilemma to the road planners.
A Dutch architectural firm, NL Architects, came up with the idea of a bridge with a twist. The concept of this bridge seeks to direct the driver on the right side of the road while visually reinforcing the same to ensure that the driver follows the correct side of the road
The Pearl River Necklace Bridge has been named “The Flipper” by the architects of the concept bridge. According to the layout of The Flipper, different sides of the road separate coil around each other such that they end up on the opposite side.