Future Long-distance Transportation: Trains versus Hyperloop?

As I rode Amtrak trains up the scenic California coast from San Diego toward Santa Cruz, I wondered about what long-distance travel here might look like in a couple decades. Will “car culture” prevail, as gas guzzlers, hybrids, and growing fleets of self-driving cars jam the highways criss-crossing Western United States? Or will airplane flights become increasingly popular and uncomfortable? Or as climate change begins to hit home and droughts heat up, will people try to avoid these greenhouse gas-emitting (and federally subsidized) modes of transportation and even avoid long trips altogether?

I took this photo from my comfortable window seat on Amtrak's Pacific Surfliner train.

I took this photo from my comfortable window seat on Amtrak’s Pacific Surfliner train.

Of course, airplanes and automobiles aren’t the only game in town. Many people frequently take trains between southern California and the Bay Area, and the trains yesterday were full of people heading north. It currently takes ten hours to traverse the distance from Los Angeles to the Bay Area, and if the state’s high-speed rail is completed according to plan, by 2029 one could make the trip in sleek bullet trains in just two and a half hours.

Here's another photo, this time from the observation car of Amtrak's Coast Starlight train.

Here’s another photo, this time from the observation car of Amtrak’s Coast Starlight train.

On the other hand, Elon Musk, CEO of SpaceX and Tesla Motors, has popularized the Hyperloop concept. This system would hurl groups of two dozen people at faster airplane-like speeds in low-pressure tubes—like the old pneumatic tubes used by banks (and human-sized tubes in the Futurama cartoon)—in as little as one fifth the time of high-speed trains. Engineers could be building the first Hyperloop pods well before the final tracks in California are laid.

High-speed rail, the Hyperloop, and self-driving cars all have their advantages and shortcomings, but my feeling is that trains will be the way to go, at least until the 2040s. I may be biased, as I’m a big fan of trains. But let’s consider the issues of practicality, budgets, and timelines.

Conceptual design rendering of a Hyperloop capsule (Credit: SpaceX).

Conceptual design rendering of a Hyperloop capsule (Credit: SpaceX).

The necessary technology for high-speed rail is already available. American engineers could build on the innovations of European, Japanese and Chinese train systems. It will be difficult to cross some mountainous areas in Southern California, but if the Hyperloop comes to pass, it will be built through a similar corridor and will face similar challenges. But engineers don’t really know how the Hyperloop could work yet, either like expensive Maglev (magnetic levitation) technology or floating on pressurized air like air hockey pucks, and many years of testing remain. They don’t even know where they might build the first Hyperloop either; it might come to Slovakia before California.

The high-speed rail project has notoriously gone over budget, as it’s now at $68 billion, twice original estimates. Legal and political disputes have plagued it as well. (Furthermore, Southern California lost out when state authorities recently decided to build the first segment of the route from San Jose, rather than Burbank, to the Central Valley.) But the Hyperloop concept is still in its early stages, and its budget estimate of only $6 billion is wildly unrealistic and has been rightly criticized by economists.

High-speed rail has dropped behind schedule, but now that people are actually in the process of building it, I think it will be completed near the current timeline, within 15 years. (It reminds me of the James Webb Space Telescope, which experienced many budget overruns and delays, but now NASA’s sticking to its final larger budget and launch date of 2018.) If the Hyperloop, on the other hand, were shown to be successful elsewhere, it’s hard to imagine Musk or someone else even starting to build it in California before then.

The technologies involved in developing self-driving cars, either for taxis or personal use, are farther along than the Hyperloop, but they’re not ready yet. Scientists predicted last year that, like trains and the Hyperloop, self-driving cars could drastically reduce greenhouse gas emissions. But these estimates assume that many Americans will jump on board these smaller vehicles and trust their software. This study also assumes no “rebound effect,” but if the cars are as good as hyped, it’s reasonable to expect that people would drive more, using more energy than before.



Finally, maybe it’s just me, but self-driving cars seem kind of strangely anti-social. Instead of expending so many resources to build thousands of cars driving in unison on the same highway, wouldn’t it be simpler to design a more efficient public transit system with already available technology? If you really like your car, you can drive it to the train station!

All Aboard to the American Astronomical Society Meeting!

I’m on a train adventure, going through California, Oregon, and Washington to the American Astronomical Society (AAS) meeting in Seattle. This post is a modified version of one I wrote for the AAS
Sustainability Committee.

For those of you astronomers and journalists at the meeting, you’re welcome to join us for our Special Session next Wednesday (7th January) at 12:30-14:00 in Room 4C-3. We’ll be starting the new year with ideas and plans for addressing climate change issues in class and with the media.

We encourage anyone who is interested in the Sustainability Committee to contact us and get involved. We will post resources on this website for teaching and discussing climate change with journalists.

It’s important for astronomers to try to make observatories, telescopes, university department buildings, and computer centers as energy efficient as possible, but our largest environmental impact and carbon footprint comes from airplane flights to meetings, conferences, workshops, etc. According to a New York Times article, air travel emissions account for about five percent of global warming, and that fraction is projected to rise significantly as the volume of air travel is increasing much faster than gains in flight fuel efficiency.

It would help this situation to develop better resources and technologies for videoconferencing and remote observing, and these are areas where we should continue to make improvements. In addition, long-distance travel can be difficult for some people, such as for those with families and those in relatively remote locations, and videoconferencing and webcasts can make conferences more accessible to more people.

Nonetheless, long-distance travel is sometimes necessary, including for early-career scientists who need to advertise their work and network at conferences. I joined the Sustainability Committee in 2014, and one thing I am trying to do and trying to encourage others to do is to take more trains. In the US, long-distance trains can be very useful depending on where one wants to travel. They are not always the fastest mode of transportation, but they are comfortable, convenient, have great views, and usually have wireless access if you need to work. And importantly, they save energy.

I work at the University of California, San Diego, and I’m taking the train up the Pacific coast to Seattle via Los Angeles, Santa Barbara, which we just passed, the Bay Area, Sacramento, and Portland. (It makes me think of Woody Guthrie’s “This Land Is Your Land.”) I’m traveling nearly 1500 miles (2400 km)—nearly the entire distance from the southern to northern border of the US. As I wrote in a blog post last summer, Amtrak trains expend about 1,600 BTUs of energy per passenger per mile, while planes use 2,500 and cars use 3,900. Trains are much more energy efficient than planes, cars, and buses, and by not flying to Seattle, I’m saving tons of carbon dioxide emissions. This is just a start, but I am trying to view flying as a luxury or necessary evil that I will avoid and reduce when possible.

In any case, I’m excited to be part of the new and improved Sustainability Committee, and if you’re interested, join us at the AAS meeting! More importantly, make a resolution in 2015 to reduce your and your institution’s carbon footprint.

For Traveling Scientists: Praise for Trains

And now for something completely different! I’d like to make the case that we should take intra-city and inter-city trains more often. (I mean this especially for Americans, since trains are already more popular and more advanced in many other countries.) As some of you know, I like riding trains, and I even thought of writing an “ode to trains,” but though I enjoy poetry—which is virtually required of me as a half-Persian—I don’t think I write it particularly well. One of my first memories as a boy was riding a train in Colorado and sticking my head out the window, only to get a face full of smoke. I’m a fan of blues, folk, and jazz music too, and many musicians (such as Woody Guthrie, Muddy Waters, Johnny Cash, Bob Dylan, Joan Baez) have sung train songs. This post is also partly inspired by an interesting and entertaining article by Kevin Baker in the July 2014 issue of Harper’s magazine.

I’m motivated by the fact that many people, and especially scientists, frequently travel long distances. Many astronomers and astrophysicists travel to conferences, workshops, and meetings as well as to telescopes. Occasionally it’s possible to interact or participate in meetings by videoconferencing and to use telescopes with “remote observing,” but it’s often the case that travel can’t be avoided, and as I’ve written here before, it’s important for junior scientists to present their work and engage in networking in person to help to advance their careers. Although most telescopes and observatories are constructed to be environmentally friendly, it is long-distance travel that results in very large “carbon footprints.”

My carbon footprint has been particularly large this year, and I hope to do better next year. I plan to begin by considering taking a train from southern California to Seattle for the annual meeting of the American Astronomical Society (AAS) in early January. Long-distance travel is also an issue being taken up by the AAS Sustainability Committee.


If you’re wondering, this trip would take most of a weekend, but it would offer nice views of the Pacific coast and the trains have free wireless internet too. It looks like the Coast Starlight line takes about 34 hours to travel from Los Angeles’s historic Union Station (pictured below) to Seattle’s King Street Station, but it covers a distance of 1377 miles (2216 km)—nearly the distance between the borders of Mexico and Canada.


We should keep in mind that, after walking and biking, trains are the most efficient way to travel. Amtrak, the US’s publicly funded railroad service, expends an estimated 1,600 BTUs of energy per passenger per mile, while buses use 3,300, planes use 2,500, and cars use 3,900! If we seriously want to use less energy and substantially reduce carbon emissions, we should travel by train much more often. From the perspective of climate change, although “carbon offset” programs have been attempted (with very limited success so far), nothing beats not emitting greenhouse gases in the first place.

Americans used to travel all the time by train, but with the triumph of the auto and aviation industries and the increased popularity of cars (with subsidized gas prices) and planes for long-distance travel, Amtrak ridership dropped to 16 million in 1972. Fortunately, ridership has doubled since then, and President Obama in 2011 committed his administration to a vision of giving “eighty percent of Americans access to high-speed rail within twenty-five years.”

The US needs to upgrade and expand its train lines and cars. Europe and China have trains that are at least twice as fast as ours, and Japan’s new Shinkansen bullet train goes 200 mph! Americans sometimes complain that the country is too big for trains, but China shows that it’s certainly possible. I think we need to push for high-speed trains, especially in California and the East Coast but also within the country, such as the California Zephyr line that links the Bay Area, Denver, and Chicago. This will take a lot of investment and time, but it will be worth it. Although the US auto industry has suffered in recent years, improving and expanding the rail system certainly would help the “green economy” and create many “green jobs”. And we should keep in mind that annual federal highway and aviation subsidies are currently gigantic ($41.5 and $16 billion in 2013, respectively) compared to Amtrak subsidies ($1.6 billion). The planned California high-speed rail will cost an estimated $68 billion to construct, but it will be built over many years.