Tunnels might look more futuristic, but I can't imagine a world where building layers of tunnels will be cheaper than larger roads. We've already put the R&D i

Tunnels might look more futuristic, but I can't imagine a world where building layers of tunnels will be cheaper than larger roads. We've already put the R&D into roads, and the cars that run on them. Routing problems have also been solved. No matter that feedback loop, it wouldn't get cheaper than laying a road. It's true that you can build many tunnels, but why? Congestion is really a problem in inner city roads. I rarely hear of any congestion in freeways, and I have to say, expanding to a couple more lanes sounds a lot more viable.