Driving doesn't fit into such a world view. Driving through a long tunnel never lasts up to 30 minutes, and tunnel lengths are never such that if your car got stranded, walking out on foot to reach the surface would challenge people with small children.

Subways are categorically a different animal. Of lesser endurance than light rail networks, the excess of amount of time spent within them is due to unintended delays and speed limits that draw out travel times. Spending more than 45 minutes on a subway trip is often viewed as unhappily inconvenient and/or an error.

> Driving through a long tunnel never lasts up to 30 minutes, and tunnel lengths are never such that if your car got stranded, walking out on foot to reach the surface would challenge people with small children.

Aside from unusual traffic delays, you are probably right about the 30 minutes thing (the longest road tunnel is just over 15 miles long), but it also has no emergency exits other than the ends, and the maximum 7.6 mile trek to an exit with both ends clear (and, a fortiori, the longer possible exit journey if not starting at the middle but a near end exit is not possible) are likely to challenge people with small children. LLP

I used to take the DC Metrorail to work. Being above ground is absolutely nicer than being below ground if you've got the choice. I looked forward to the parts of that train commute that were above ground. There was even a part where we would come out of the tunnel and I'd look behind me to view the Washington Monument. It was great, especially at night.

I would rather take a short trip underground as the alternative to a long trip above ground, given the option.

When I need to get from A to B, I just want to be there quickly. I can enjoy the surface of the Earth on my own time.

My specific point was about how to address a coming traffic crisis, sorry if that was unclear. I'm suggesting that 90% of traffic will be unaccompanied "stuff" and that moving it underground will free up traffic for people above ground. So either way, we're both talking about getting from A to B more quickly.

I'm sure there will be a need that arises for more tunnels for people, too. But I think the place to START and allocate resources is tunnels for stuff since that's where the problem will come from.

I think that we should consider total underground transportation as a design goal. Even if we reduce, say, the highway traffic by 90%, the remaining 10% will still deal with weather conditions, peak usage times, and bottlenecks such as construction or traffic accidents.

There are plenty of reasons to move people underground rather than above, along with goods. My personal interest in this is that a scalable 100% underground transportation system would make for a better model for life on the moon or Mars than anything we currently have on Earth.

Besides, traveling underground doesn’t have to be a dreary, dystopian experience. If we moved people in rectangular structures resembling elevators, we could cover the floor and ceilings with LCD screens, so instead of feeling like you’re inside an elevator, you could set the screens to show a panorama of the city you’re in, or the Swiss Alps, or if you throw a camera and microphone in there, you could attend a meeting while you’re on your way to that meeting.

Even if we get goods moving off the roads, personal transportation still has enormous costs. Just ask any American who has had to choose between paying high rent to live close to work, or buying a car to commute further away from their lower-rent home.