How would you get cars up to the roads 20m above the ground? How would you handle maintenance of buildings connected to suspended roads? Are there seismic safeg

How would you get cars up to the roads 20m above the ground? How would you handle maintenance of buildings connected to suspended roads? Are there seismic safeguards for structures like this? All real questions, I'm fascinated by this idea but clueless as to how it could be implemented.