China-Hong Kong Necklace Bridge Project [Video]
As you already know, Chinese drivers use left-hand drive vehicles (right hand side of the road), while the ones in Hong Kong, a region which has been under British rule for the better part of the 20th century, use right-hand drive vehicles (left hand side of the road).
The solution proposed by NL Architects is a bridge called Pearl River Necklace. The bridge is a "Flipper," or switchover construction, with the halves of the roadway splitting and crossing over and under each other. This allows for the left hand side of the road to be directed to the right hand side of the road when entering China and the other way around when heading to Hong Kong.
"The Flipper is a device that is designed to 'celebrate' the traffic switch," an NL Architects statement is cited by csmonitor.com. "Can we turn the moment of swapping into an unforgettable spectacle?"
The project was inspired by the Hong Kong Boundary Crossing Facilities International Design Ideas Competition, a contest meant to develop a bridge idea to link the city of Zhuhai in China with the western part of Hong Kong. Although not part of the competition, the project might be a vision of how lane switching between countries can be done in a more stylish way than the plain and ordinary road sign.