Ok, so one thing I've noticed reading the 120 comments in this thread and the article is that literally nobody knows anything about boring, or tunnels. Musk knows nothing, he put someone in charge who knows nothing, the reporter knows nothing, and the commenters here even admit they are completely guessing and know nothing about boring/tunnels. I definitely don't know anything about tunnels.<p>It's a joke that came to life, and it's a pretty funny one, and I'm fairly confident Musk can make improvements, but I'd still like to know something about the whole process.<p>I assume someone here knows something about this, or at least can find out, so here's my wishlist:<p>- Has there been any improvement in boring in the last 50 years? The frequently-repeated statement that it hasn't improved would be quite shocking to me since at the very least I'd expect safety to improve.<p>- What are the maintenance costs of tunnels like as compared to surface roads?<p>- What are the big costs in the industry? The article hinted that Musk picked up a boring machine for 90% off $15MM, or $1.5MM, which seems extremely cheap given that even small size tunnels in urban areas can cost more than one -billion- US dollars per mile.<p>- Is there enough boreable space under our cities that this is doable? I know Musk says he wants to go deep, but even at very deep depths you run into problems of sand, boulders, geography, etc, etc.