[tokipin]

The key is that this system can operate in 3D. You can have bundles of tunnels where you need higher throughput, and greater demand can just be met with more tunnels. The focus on small tunnels/cars as the core technology is part of this, since it makes it easier to reach "mass production" scales.

[cozzyd]

So to first order, you'd have to build as many tunnels as there are road lanes to get the same order of magnitude throughput? I get that there is more space underground, but this sounds completely cost ineffective given that many municipalities can't afford to maintain their roads.