This is the final post in a series of three exploring the evolution of passenger transport locally, regionally, and globally over the next century. The first post, discussing regional transportation, is here; the second post examined ideas for local transit.

In this series of posts, I have described possibilities for how people will travel over short-to-medium distances perhaps twenty or thirty years from now. Locally (meaning within a metropolitan area), my bets are on personal rapid transit in the form of podcars (perhaps suspended from guideways like SkyTran) and self-driving taxis. To travel greater distances, between cities in heavily-populated regions, I’ve predicted that we will use something betweeen tube capsules, like in Elon Musk’s Hyperloop idea, and high-speed rail.

But what about traveling long distances, such as between New York and Los Angeles, or London and Hong Kong? Global transportation is the final tier of future transit technologies. More importantly, when we behold the full picture of local, regional, and global transportation, broad trends emerge that whisper of how we will live and travel in the middle of the 21st century.

Imagine, for a moment, that it’s 2035, and you’re preparing to travel to Shanghai, Dubai, Buenos Aires, or some other city on the opposite side of the globe, across continents and oceans. Today, you would almost certainly be boarding an airplane for a not-very-comfortable sixteen-hour sojourn in a cramped seat. For most destinations in the world, I doubt this will change by 2035, and perhaps never will, unless teleportation becomes a reality. (Sorry.) But, to connect certain important regions, pairs of the so-called “global cities“, new methods may appear.

Some of these look like leviathan Hyperloops or high-speed rail systems. One very persistent engineer, Daryl Oster, has designed and patented ET3: a Hyperloop lookalike that conceptually predates Hyperloop by a couple of decades. ET3, which dubs itself “space travel on Earth”, places capsules for a handful of passengers each in an evacuated tube, then accelerates them up to a maximum velocity of 4,000 miles per hour. Tubes would stretch from Europe through Asia and Africa, across the Bering Strait between Siberia and Alaska, then down through the Americas to reach every major metropolitan region on the planet. A trip from New York to Beijing would take a mere two hours. At first glance, I thought it ridiculous, but as I studied the proposal more carefully I started to wonder. Ridiculous twenty or thirty years from now, yes. But in the later decades of our century, or early in the next? ET3 might be much more reasonable by then.

In the meantime, air travel will remain the best bet globally. Here, too, I expect that speed will be the defining factor in which technologies take hold long-term for passenger transport. In aviation, maximum speed means supersonic flight. Although the cancellation of Concorde in 2003 was a setback for commercial supersonic travel, new technologies are in development.

The most interesting of these is the LAPCAT A2: a design for a commercial supersonic vehicle from Britain’s Reaction Engines Limited (or REL for short). The A2 is not a “jet” in the normal sense of the word; it’s essentially powered by the prodigal child of a jet engine and a rocket. The reason why is because of the shortcomings of both jet engines and rockets. Jet engines are wonderfully efficient, but each different variety of them operates well only at a narrow range of speeds, and they get trickier to use the faster you want to go (the problems are of the “air is getting really really compressed and heating up too quickly oh god the engines have melted mayday mayday” variety). Rockets, by contrast, are great at going fast, but they have to carry all of their propellant, while jet engines can scoop oxygen from the atmosphere to burn their fuel. REL, in the quest to build a Single-Stage-to-Orbit spaceplane, developed a rocket engine called SABRE that uses atmospheric oxygen to burn hydrogen fuel, thus eliminating much of a spaceplane’s weight. They also tweaked SABRE to create a variant for supersonic flight, and it is this engine, known as Scimitar, that they attached to their A2 concept.

Artist's rendition of LAPCAT A2 at an airport.

The LAPCAT A2 would be a massive supersonic airliner seating 300 passengers. Image from Reaction Engines Limited.

The A2 is able to cruise at above Mach 5 (4000 mph), and also operate comfortably at subsonic speeds. This means that the 300-passenger plane could fly from Brussels to Sydney in 4.6 hours, taking an indirect route over the North Pole to avoid producing sonic booms over populated land masses. Yes: 4.6 hours to travel more than halfway around the Earth. Eat lunch in Europe, then rocket over to dinner in Australia.

There’s no doubt that ET3 and the A2 sound like science fiction—all the technologies featured in this series do. None of them will show up tomorrow, unless you happen to be lucky (or unlucky) enough to have a demonstration version of one built in your neighborhood. Critically, however, most of them are just tens of millions of dollars away from existing in a simple form, and are getting cheaper each year. I expect to see all of them appearing over the next two or three decades. Which ones will stick around and become popular depends on what travelers think of them.

I’ll conclude this series with a list of the most salient features of the transportation technologies I’ve covered. These are the definitive factors, as I see them:

  • Fast. Every system I’ve looked at is focused on one thing: get people where they want to go as quickly as possible, even if it means sacrificing a bit of comfort.
  • Passengers only. Interestingly, none of the systems are optimized to carry cargo. This is a big deal; historically, all transport infrastructure—roads, railways, boats, planes, rockets, etc.—have been scaled so that they could move either guys or goods. It’s possible the inventors have only focused on passenger transit, and that cargo variations could be incorporated later, using the same tubes, guideways, airframes, etc. But it’s also possible that cargo and passenger transport could split, with slower, more traditional options (roads, rail, perhaps even airships) being used for shipping stuff.
  • Sorry, no windows. This one is weird, and I wonder if its hinting at a lot more than just transit styles. Of the systems I’ve discussed, three of them (the Hyperloop, ET3, and the LAPCAT A2) are windowless. This is ostensibly for engineering reasons; either the designers think it stupid to put windows in a capsule that will be in an enclosed tube, or the vehicle is moving so fast that windows would be very bulky. The universal recommendation is to include electronic displays that could show pictures of what’s outside, entertainment, or something else. (“Elevator scenery”—it’s not just boring music anymore!) I’m just not sure that suffices.
  • On demand. Most of these services could be called up as needed, even to the point of having a vehicle arrive at your location at a set time. This will largely eliminate set routes and stop times, except for mass transit vehicles like the A2.
  • Humans need not apply. None of these technologies (with the possible exception of the A2) need drivers, pilots, or the like. They are all autonomous, guided by either their own inner electronics or a central mega-brain. Yes, this will eliminate quite a few jobs, except for computer programmers. Which leads to…
  • Hail the Algorithm. Computers are a lot better at processing millions of moving things than humans. With all these autonomous vehicles on roads, guideways, tubes, and air lanes, a central system governing their movements makes sense to avoid traffic jams and other backups. It could easily track current traffic, and reroute certain vehicles to ease congestion. Even more notably, it could pull from other data sources to predict future traffic levels with eerie accuracy. Imagine: 18 minutes until the end of a ball game, 47,681 people in the stadium, pods lined up outside to take them all home. The transport algorithm knows exactly who these people are (thanks to social media) and where they will go next (thanks to social media and/or their requests for transit). It is therefore able to route all those pods smoothly. On a darker note, it could also reroute any vehicle to an unintended location without the occupant having any control. Police apprehending fugitives would love this. Dystopian police-state agents would also love this.
  • Megalopolis. The most economically effective places to build these systems will be in major, interconnected urban areas. Central cities and their suburbs will therefore be well-served. Rural regions and small towns in the hinterland could see little or no service, combined with general degradation of their existing transit systems as capital focuses on the megalopolises of the world. There’s an interesting future here for our whole social structure. That, however, is a topic for another time.

Those are my thoughts, certainly incomplete. What do you think? Do you have ideas about how these trends might change the world, or about what other trends I might have missed?