Independent of the tunnel, a network of sleds able to move vehicles at one sled per vehicle... is going to be ludicrously expensive and the maintenance costs wi

Independent of the tunnel, a network of sleds able to move vehicles at one sled per vehicle... is going to be ludicrously expensive and the maintenance costs will be huge. Current roads don't need sleds, sled tracks, elevators, switching and management, safety gear etc, and that's even before we get to the usual tunnel needs of ventilation, pumps, and lighting. It seems a bit odd to be proposing very high maintenance infrastructure at a time when the US is famously facing a huge problem in not being able to afford maintenance for its existing infrastructure.