Tag Archives: Fantasy Transit

Hyperloop: lots of hype for something that doesn’t yet exist

Hyperloop

The last few days have seen lots of pixels spent on Elon Musk’s Hyperloop concept – and I couldn’t resist chiming in. It’s a fascinating idea, but far from an actionable one.  Musk seems to have put a lot of thought into dealing with some of the technical hurdles of previous vac-train ideas, but rather than put these forward in the marketplace of ideas, he has taken to bashing California’s high-speed rail project instead.

Musk’s supporters take his endorsement seriously, with many openly hoping that the Hyperloop will kill off high speed rail, even though high speed rail is a proven technology operating around the world, while the Hyperloop exists nowhere but as a sketch on the back of a cocktail napkin. It’s a testament to the power of an idea, but it also shows how easily we can fall for bad ones.

A few base criticisms of the idea come to mind: the Hyperloop is not necessarily a superior technology for the problem it seeks to solve (travel between SF and LA); technology does not change the basic geometry of a transport system (and it must respect the basic tolerances of the human body); a fancy new technology is not necessary for innovation and improvement; and every strain of common sense indicates that the cost projections for this thing are pulled out of thin air (where else would they be pulled from?)

Solving SF to LA: Musk’s proposal does not actually serve either Los Angeles or San Francisco. The ‘last mile’ problem in any urban transportation system can be really challenging and really expensive. Musk simply avoids the problem by terminating in Sylmar and the East Bay. The hyperloop’s faster speed is irrelevant to the real question: travel time. Maximum speed alone tells you little about travel time, just as the Acela Express (as limited as it is) easily takes the majority of air/rail traffic between DC and New York, despite slower vehicles and longer trip times – the benefits of easy boarding (Penn Station be damned), downtown station locations, and relatively low security requirements make for a better overall value. 

Musk didn’t just pitch the hyperloop as a way to make evacuated tube trains feasible, he pitched it as a way to make SF-LA travel work better than the CHSRA can. His pitch is part technical concept and part policy proposal, and the policy elements fall short.

Technology does not change geometry: This is true for driverless cars and for hyperloops. The type of technology used doesn’t change the technology’s purpose – moving people from place to place. Since the hyperloop is essentially a transit service, it still must obey the same geometric rules as all other modes, the ones that govern capacity, headway, throughput, etc. Musk ups the speed for his concept, but his own proposals show a very low overall capacity – and even those estimates seem optimistic given his assumptions on safety margins and safe distances between pods. At GGW, Matt Johnson compares capacities of different modes of transport:

According to Musk, pods would depart LA and San Francisco every 30 seconds during peak periods. Each pod can carry 28 passengers. That means that under the maximum throughput, the Hyperloop is capable of carrying 3,360 passengers each hour in each direction.

For context, a freeway lane can carry 2,000 cars per hour. A subway running at 3 minute headways (like the WMATA Red Line) can carry 36,000 passengers per hour. The California High Speed Rail, which this project is supposed to replace, will have a capacity of 12,000 passengers per hour.

Technology also does not magically change the tolerances of the human body (save for science fiction inventions like inertial dampers). Musk is selling speed, and his assumptions on acceleration are more akin to a roller coaster than rapid transit. From The Verge:

According to Powell, that’s a problem: “In all our tests, we found people started to feel nauseous when you went above 0.2 lateral Gs.” The closest comparison would be roller coasters, which usually top out around half a G — but the Hyperloop wouldn’t just peak at 0.5; it would stay there for the duration of the curve. The result would be well short of blackout, which most studies peg around 4.7 lateral Gs, but it would make the Hyperloop challenging for the faint of stomach.

Others have noted the lack of bathrooms in the Hyperloop pods. It would seem that the roller-coaster analogy is apt, as roller-coaster operators don’t want you leaving your seat in the middle of the ride, either. It’s not safe.

Other opportunities for innovation: Much of the praise for the Hyperloop seems to be based solely because it’s something new and exciting (and people take Musk’s cost claims at face value); part of it also seems to be a lack of faith in high speed rail. The desire for something new ignores the reality that most innovation is incremental; it also ignores the power of transportation networks and the value of connecting to something that already exists.

Matt Yglesias looks at alternative transportation improvements that would seek to solve the same problem (decreasing LA-SF travel time) by tackling some low-hanging fruit, rather than inventing new technology. Yet, people don’t want boring improvements in processes. Molly Wood at CNet just wants to believe in technology, noting that practicality is for cynics:

I refuse to keep accepting that until our cynically imagined dystopian future comes to pass. As justone alternative to the essentially already-failed high speed rail project, we now have a detailed plan for a high-speed transit system that could cost as little as $6 billion to build and, by the way, would be solar powered and infinitely more environmentally friendly than the dirty, diesel-powered rail project. It seems obvious that Musk is unveiling this plan ahead of the ground-breaking for the rail project in what is hopefully a successful attempt to stop the monster from ever being born. So get over the sunk cost fallacyof the California “high speed rail” and move on to a better solution.

All we citizens of California, and the Internet, and the world, have to do is believe that this technology is possible. Then those of us with the lucky happenstance of representative government should use it like it’s supposed to be used, and demand better. Instead we tend to give up and talk about great ideas that will never happen — or worse, tear those ideas down as silly, unrealistic, or impossible.

Leaving aside Wood’s unquestioning acceptance of Musk’s cost estimates f0r a technology that doesn’t exist (even in prototype!), and the obvious mis-information about HSR’s power source, this kind of technological evangelism is fine for entrepreneurs (as Alon Levy’s post title argues), but it makes for bad public policy. If Wood had the same faith in HSR, and was willing to look over HSR’s faults with the same starry-eyed gaze, then HSR wouldn’t have the PR headaches that it does.

Slate’s Will Oremus is similarly infatuated with the concept, but at least he realizes the steps required for the Hyperloop to prove itself worthy:

Wise or not, California is unlikely to drop its plans just because one rich guy has a light bulb over his head. On the other hand, if Musk does build a demonstration line, and it’s faster, cheaper, more energy-efficient, and requires seizing less private property than laying down train tracks, a change of plans might start to sound pretty appealing. That’s a lot of ifs—but so is every big idea, in the beginning.

Indeed, that is quite a few ‘ifs.‘

The odd thing is, despite all of the references to Musk as a master innovator, it’s worth noting that all of Musk’s companies and products, as daring and inventive as they are, still are just incremental improvements over existing technology. Tesla did not invent the electric car and certianly did not build the massive network of auto-centric transport. SpaceX did not invent rockets. SolarCity did not invent solar power. Each company offer incremental (though meaningful) improvements on existing concepts and products.

At the risk of stating the obvious: Hyperloop is not an incremental improvement for an existing technology. Existing technologies have the benefit of linking into existing networks. Tesla’s cars can use regular roads and charge through regular outlets. High speed rail can use existing tracks and rights of way to get into city centers.

This is not a serious cost estimate: Musk is not just proposing a new technology, he is also offering an explicit critique of high speed rail. Plenty of observers have critiqued the CHSRA’s track record to date; comparisons to HSR best practices in planning, construction, and operation from around the world are not favorable. Nevertheless, this does not make the Hyperloop’s assumptions any more realistic. And, if the state were to buy the hype, the Hyperloop would likely see even wilder cost overruns – putting it on the same trajectory as Seattle’s failed monorail transit system.

Alon Levy takes a closer look at some of Musk’s cost estimates, and finds that most don’t even pass the smell test:

This alone suggests that the real cost of constructing civil infrastructure for Hyperloop is ten times as high as advertised, to say nothing of the Bay crossing. So it’s the same cost as standard HSR. It’s supposedly faster, but since it doesn’t go all the way to Downtown Los Angeles it doesn’t actually provide faster door-to-door trip times.

At a broader level, consider what Musk is claiming: that a system of precisely aligned and machined de-pressurized tubes could be built for a fraction of the cost of infrastructure with a similar footprint. Musk is proposing that the pods would clear the tube walls by fractions of an inch, compared to much larger machined tolerances for lower-speed modes of travel:

The biggest question mark is the tube itself, which has emerged as the most genuinely unprecedented part of the plan. By enclosing the track, the Hyperloop is able to sidestep worries about air friction and noise that usually limit the speed of trains to under 400mph, but the tube also presents a unique set of challenges. James Powell PhD, co-inventor of the maglev train, is particularly concerned about the smoothness of the inside of the tube. As Powell points out, the current design allows for just three hundredths of an inch between the tube wall and the skis encircling the pod. “Getting it that smooth won’t be easy,” says Powell, and might require a more expensive production process than the plans envision.

The small gap is crucial to the system’s overall design, allowing for a stable air cushion that keeps the pod hovering frictionlessly in the tube. But the small gap also requires great precision in tube construction. Powell thinks that a single bump, just three-quarters of a millimeter high, would trigger catastrophic damages, possibly even ripping the ski from the pod at top speed. Keeping the tubes straight can be done, but it won’t be cheap. “It’s going to be an arduous process,” says Vinod Badani, an engineering consultant at E2 Consulting. “Quality control and measurement have to be very accurate.” Musk’s plans envision a specially designed device to smooth out the inside of the tube, but it presents a serious engineering problem for anyone thinking of building a prototype.

Musk proposed using I-5’s right of way as a way to keep land costs down. However, I-5 has trucks. If one semi truck jack-knifes on the road, ramming into one of Musk’s cheaply-built pylons, how will his tube maintain that level of precision required for safe operation? Musk asserts his system is safer than HSR during earthquakes (nevermind the safe operation of Japanese HSR during major earthquakes) without any evidence, yet the basic physics of what he is proposing demand a high level of precision on a massive scale.

The real question should be if it’s even possible, not asserting that it will be cheap.

In the New Yorker, Tad Friend takes note of Musk’s propensity for exaggeration:

The bad news is that there’s no conceivable way that the system would cost just six billion dollars, or that one-way tickets would cost twenty dollars. Overpromise disease is endemic to Silicon Valley, but Musk has an aggravated case. When I wrote a Profile of him, in 2009, he told me that a third-generation Tesla would be selling for less than thirty thousand dollars in 2014, the same year that he expected SpaceX’s Falcon 9 to begin ferrying tourists around the moon. Well, no and hell no. More worrisomely, he promised that you could start driving the Model S in western California “at breakfast and be halfway across the country by dinnertime.” Musk is a lot better at math than I am, but he eventually acknowledged that by “dinnertime” he really meant “the following morning’s breakfast”—if, again, you didn’t stop to go to the bathroom.

This isn’t to argue that exploring these ideas shouldn’t happen. It is, however, an argument that a concept like the hyperloop shouldn’t be used to bring down high speed rail. If the Hyperloop is nothing more than a device to force better results out of the CHSRA, that would be a welcome result. However, if that is to happen, it won’t be because the Hyperloop is a realistic (or event a plausible) alternative.

Two weeks ago, Eric Jaffe editorialized that we should stop obsessing about the “next great thing” in urban transportation. There’s thinking big, and then there is fantasy. It’s worth noting that a project like California High Speed Rail is plenty ambitious – it’s certainly thinking ‘big.’ It’s also achievable, but is facing real-world constraints (economic, political, physical, institutional, procedural, regulatory, etc) and is in need of some practical planning.

The Hyperloop may seem like an attractive end-run around these constraints, but such benefits are illusory. The real benefit is in reforming the institutions to reduce the constraints.

Towards a DC S-Bahn

S-Bahn logo. From wiki.

This week, Greater Greater Washington has run a series of posts on the hurdles to implementing through-routed commuter rail services in DC. The technical reasons include many basic incompatibilities between the region’s two commuter railroads (MARC and VRE), ranging from type of locomotion to platform height, as well as the infrastructural shortcomings of DC’s rail infrastructure to handle high frequency transit-like operations.

Lost in the wash, however, is the reason to do this.  The reasons are two-fold: First, through-routed service expands the transit network relatively inexpensively, offering mobility benefits to current and future riders.  Second, such a service (and the technical changes required to implement it) help solve some of the other challenges of DC’s commuter rail network (such as insufficient storage capacity at Union Station for trains to layover mid-day). Through-running is both a means to an end as well as an end itself.

This isn’t exactly a new concept, as it has been raised in numerous places over the years:

Plus the southern intentions of intercity rail:

CSX’s plans for increasing freight traffic will also mean added capacity through DC, with implications for passenger rail.

None of these plans hints at even the possibility of the kind of S-Bahn integration potential that through-routing unlocks.

The goal should be to turn the core of DC’s commuter rail network into a system like Germany’s S-Bahns (touched on previously here and here).  David Alpert essentially suggested the same thing with his conception of the ‘Metro Express.’  The level of service would be more like rapid transit than commuter rail.  The geographic extent might not be as expansive as the current commuter rail network (there’s no sense in running rapid transit to Martinsburg, WV) but those outer extensions could easily be serviced by a service that mirrors today’s commuter rail.  The core of the network (say, to Woodbridge in the south, Manassas in the west, Germantown or even Frederick to the north, and Baltimore to the east) would see higher frequencies, through-routed service, and all-day, full week service.

One common characteristic of S-Bahns is the use of interlining and shared tracks in the core of the system (this Wiki diagram illustrates), where interlining produces short headways on the shared portion while the outer parts receive less frequent service due to the branching of the network. The three MARC lines feeding DC, each running on 30 minute headways would combine for 6 tph in the shared segment (Union Station to Alexandria).

VRE’s timetable shows Alexandria-L’Enfant at about 17 minuntes; Alexandria-Union Station at about 25 minutes.   There’s room for massive improvement here – Metro’s trip planner shows King Street to Union Station (Yellow to Red) as 20 minutes on Yellow, 4 minutes on Red; King Street to L’Enfant Plaza is the same 17 minutes on the Yellow line.

Give a DC S-Bahn transit-like service and that can be reduced.  Electric multiple unit trains would accelerate faster; level boarding and more frequent service would shorten station dwells; etc. Then, the commuter rail infrastructure would function as a key part of the region’s rapid transit network.

 

Metro Fantasies – now with pictures

Following up on my previous comments about Metro expansion and a new Yellow line, I wanted to add some graphical representation of these ideas.

First, the current Metro system:


View DC Metro in a larger map

My plan includes the Silver line as currently planned and under construction, as well as my conception of the new Blue line (shown in teal) as well as a separated Yellow line (shown in Goldenrod), with separation from both the Green like through DC and from the Blue line through Arlington and Alexandria.  The new lines only are here:


View DC Metro Expansion in a larger map

Combine both the current system and the new plans, and you get this:


View Combined Metro Map in a larger map

Old tracks are in blue, new tracks in yellow.

Obviously, these maps have no stations (yet).  It’s safe to assume that where two lines cross, you’d want to have some sort of a transfer station there.  With new lines crossing (thinking specifically of the intersection of North Capitol and H St), you could have a brand new Metro Center-esque station, linked by tunnel to the current Red line stop at Union Station.

The purpose of putting these lines on these streets is merely to define the corridors and ensure some feasiblity in terms of potential rights of way and station areas, but they shouldn’t be considered concrete decisions.

Adding to Metro’s Core Capacity

Greater Greater Washington’s always had some great fantasy transit discussions – whether talking about the New Blue line, more fantastic visions, or even the multimodal vision for Baltimore and DC.  Over the last few days, the fantasy discussions have started again.  Though these are not always the most realistic discussions, they’re a great starting point for larger discussions about the role of transit in the transportation system in the city, and more importantly they discuss what kind of city we want to have.

This past week’s discussions have focused on the idea of a new Yellow line – originally posted here, along with my response.   The entire premise of separating the Yellow line from the Green line (at least as I understood it) was to increase the maximum capacity of both lines – the same premise behind the idea of separating the Orange and Blue lines.  That way, both colored lines would have full capacity for their entire length.  Doing such a project would also have ancillary benefits, such as adding redundancy to the system with multiple tracks on fairly similar routes, as well as opening up new areas to Metro service (such as adding Metro service to H Street NE with the New Blue line).  Each of these ideas is worthwhile, though slow to implement.  Given the facts that Metro is already straining to handle the crowds along the Orange line though the RBC, focusing on this kind of long term planning is important.  Building new subway lines will take a long time, and with Metro expected to reach capacity sometime between 2025 and 2030, starting the planning process now is vitally important (i.e. Metro was recommended as the preferred alternative for the Dulles Corridor in a 1997 report – the full line is now set to open in 2016 – nearly 20 years after the fact).

With that in mind, proposals that involve a great deal of capital construction must have a long term plan behind them to justify the investment.  The idea of separating the Blue and Orange lines is a good start.  Having a longer term plan to separate the Green and Yellow lines is also a good idea – even better would be to combine those efforts sowe have a nice 50 year map to follow for Metro’s development over time.

The lack of this kind of focus and long term vision troubles me with GGW’s latest series of posts about adding new trackwork in downtown DC.  The premise is a simple question: is there a simpler and cheaper way to add core capacity to Metro without building the entire New Blue line?

How about separating the Yellow Line instead? The Yellow Line plan Dave Murphy suggested last week, and some of your comments, suggest a possibility. If we separate the Yellow and Green lines in DC, then Metro could put many more trains over the 14th Street bridge. According to Metro planners, this option would involve building a shorter subway tunnel from the 14th Street bridge to the Convention Center along 9th Street.

While the tunnel at Rosslyn is already at its capacity, the 14th Street bridge isn’t, because all its trains must merge with Green Line trains from Branch Avenue. Metro can squeeze a few more Yellow Trains in if they reduce Blue trains, but not that many. If the trains didn’t have to compete with the Green Line, the 14th Street bridge could carry many more trains from Virginia.

The second iteration of the idea also generated a great deal of discussion:

If we could run more trains over the 14th Street bridge, where would they go in Virginia? I can see two possibilities: convert the Arlington Cemetery segment to a shuttle train, or add connections to route the Silver Line over that segment as well as the Blue Line.

Both of these ideas are intruiging from an academic perspective, but completely lose sight of why you’re adding core capacity in the first place.

Remembering that the whole point of the New Blue line is to separate it from the Orange line tracks it shares through DC, the reason it gets brought up first is due to the popularity of the Orange line in Northern Virginia.  This GGW idea is an attempt to solve that same problem by essentially starting on a new Yellow line.  You’re essentially building half a subway, except that you’re building the New Yellow line first when the Blue line is the obvious choice.

If you’re going to put shovels into the ground, you might as well make sure that the plans have long term significance.  Metro’s genius is that it was concieved as an entire 100 mile system.  Even so, it functioned well before the full system was complete.

WMATA should take the same step here.  If you want to add new capacity to downtown DC by building half of a new subway, just start building the new Blue line – and do it in phases.  The first phase (say, from Rosslyn to the Connecticut Ave station) would accomplish the same thing – freeing up core capacity on the Orange (and Silver) line, as well as delivering Blue line riders to the core of downtown.   However, unlike the 9th street proposal, the Blue line would be readily expandable at a later date, much like how the Mid City portion of the Green line was completed in phases (with U Street opening in 1991, while Columbia Heights didn’t open until 1999).   Ideally, you’d like to do it in one fell swoop, but the entire premise of this idea is that the funds to do such a project aren’t there.  So let’s at least plan it with expansion in mind.

With that said, the idea of a new Yellow line isn’t a bad one at all, even if the timing isn’t quite right.  However, using 9th street doesn’t make a lot of sense when you already have lines along 7th and 12 streets downtown, and along 14th street in Columbia Heights.  The alignment proposed in the original post makes a lot more sense when viewed with a long-term lens.  A 9th street alignment would indeed be redundant, but almost too redundant – it wouldn’t open up any more area to Metro service, such as the transit poor Washington Hospital Center.  A North Capitol/Georgia Ave route would provide redundancy for both the eastern Red line, the whole of the Green line, and open up a major commercial street to Metro.  This line could also be phased in over time, initially operating as just a partial segment.

As Burnham said, “make no little plans.”  If you’re looking for incremental physical improvements, I’d opt to ensure that they’re part of a larger plan.  The final result will be far better for it.

Fantasies

Dave at Imagine DC (and also GGW) put up a nice concept of a separated Yellow line through the core of DC.  Separating the Blue line has been the most popular suggestion, and was originally among WMATA’s official plans, but the idea of separating the Yellow line is relatively new.   Still, amongst extensive discussion in the comments from previous fantasy maps, the idea has come up before – my name is somewhere in those comment threads.

Given the focus that Monday’s accident has put on redundancies in the transit system, it’s fitting to consider the idea.  However, it’s important not to lose sight of the reasons for such plans and expansions in the first place.  With that in mind, I’d propose a few key principles to consider for any metro expansion plan:

  • Separation of the current interlined portions of track.   The proposals to separate the Blue and Yellow lines certainly do this, and for good reason.  The ‘tail’ sections of each line are limited by the capacity of the shared track at the core.  Furthermore, the complexities of switching so many trains on and off the same line only adds to potential delays.  Separating these lines would offer wide ranging benefits to other lines in terms of increased service frequencies.
  • Plan the entire system now.  By ‘now’ I don’t mean today, but if plans are drawn up to implement this kind of expansion, it is vitally important that the lines are planned together.  The fact that all 100+ miles of Metro were planned as a coherent system is what makes it such a useful system today, rather than a hodgepodge of individual lines.  If you look at the poor connections between Baltimore’s light rail and subway, you’ll see precisely what you wish to avoid.  That means planning to separate the Blue & Orange lines, the Yellow & Green lines, and the VA portions of Yellow & Blue at roughly the same time.  Doing so, like the original system, will allow for transfers to be built in and will make for a much better overall system.  Begin with the end in mind.
  • Learn from Metro’s past. Metro’s hybrid nature as both an urban subway and a suburban commuter rail system makes for some interesting compromises in terms of system design.  Given that the newer portions would entail track mostly in urban areas, it’s important to apply the lessons of Downtown DC, the Rosslyn-Ballston corridor, and others.  This is about urban transit, not park and ride stations.
  • Coordinate plans with other modes. Metro expansion should focus on the core because that’s where it’s most useful and can justify the cost.  Ideas like extending the Orange line to Centreville, or the Green line to BWI miss the opportunity to have a newly beefed up regional rail system operating in place of MARC and VRE trains.  Ideally, such Metro expansion plans would be coupled with a transformation of the commuter rail services into a more S-Bahn like system.  In the other (more local) direction, coordination with streetcar planning is also vital.

Speaking in terms of broad corridors, Dave’s plan for the Yellow line is spot on.  I think he’s got too many stations for a heavy rail line, but the general corridor is correct – the line would use the same bridge over the Potomac, then go underground and follow the Maryland Ave right of way, linking to L’Enfant Plaza with a new platform for the station complex.  The line would cross the Mall, then travel north under North Capitol, including a station at H street – which would also be part of the station with the new Blue line – also connecting to the current Union Station stop (hence the importance of planning these lines at the same time).  The line should go up to the Washington Hospital Center, serving that major employment center, then sliding to the west somehow to turn northward again under Georgia Ave.  After reaching Silver Spring, the line can either end there, or continue north along US 29, as proposed by Sand Box John.

The Blue line has been discussed many times – I think the best alignment would be across town under M street, angling southward under New Jersey Avenue, and then continuing east under H street – ideally with transfers to the Red line at both Union Station and under Connecticut Ave, as well as a Green line transfer at the Convention Center and a transfer to the new Yellow line near the Union Station complex.

Separating the Blue and Yellow lines in Virginia is probably the easiest route to conceptualize – simply shooting the line outward under Columbia Pike is the most obvious choice, making the current line to Alexandria one ‘color’ with multiple spurs – one to Huntington and one to Franconia-Springfield.