2-D systems in a 3-D world

The problem with transportation is that it is a 2-D system of roads, while we work and live in 3-D buildings and houses. Until transportation changes to a three-dimensional systems, there will always be traffic.

Option 1 - flying cars, the problem with those is that are noisy and displace so much air that it becomes a major problem. Think about flying drones and how much noise they make, now times that by 1000 for a flying car. Basically put wheels on a helicopter. Your neighbours would hate you when you land your car any time after 8pm.

Option 2 - build tunnels, we can go 100 levels into the ground, deeper than the height of any skyscraper out there. With tunnels we could arbitrarily alleviate traffic in any area on the planet.