Flatlanders

Tunnel Construction Explained
The B1M

Driving to the airport the other day I was noticing the freeway. It's concrete and it's dirty. I mean the road would probably like to be clean, but with a zillion cars passing over it every day shedding tire and brake dust and dripping oil, it's just not going to be clean. Bridges and complex interchanges can be impressive with the sweeping loops and glorious arches, but they are still going to be filthy. It's kind of sad because cars are like our main religion. Where we all used to tithe to the church, now we tithe to automotive industry and the oil companies.

For a long time I have thought that making cities multi-level with cars on a lower level and people on an upper level would be the way to go. Cars occupy about half of the land area in most urban and even suburban areas. Just look at the streets, parking lots, garages, driveways, repair shops, gas stations and automobile dealers. It's kind of mind boggling. It shouldn't be a big deal to make an upper level just for people, I mean a car weighs twenty times as much as person.

Then I realized, yes, that is true, but those numbers only make sense if people will keep their distance, and it you know anything about people, you know they won't. For some inexplicable reason they like to clump together. A fully loaded semi-truck can weigh 30 tons. That semi-truck will cover 400 square feet. You can easily pack 100 people in that small an area. Maybe not comfortably, but imagine the press of a crowd trying to get through the gate for a concert, or trying to get out the exit when a fire erupts. In a panic you might have twice that number. But let's just stick with 400. 400 people times 200 pounds each ('cause this is America) give you 80,000 pounds or 40 tons. That's more than a heavy truck. So that upper level that only needs to be able to hold light weight people is going to need to be stronger that interstate highway bridges.

We can build structures to support that much weight, but they are expensive. So maybe Elon's crazy idea of digging tunnels for new highways is not so crazy after all.