High-Speed Rail and Cities

When preparing various maps proposing high-speed rail in Germany, I was told that it looks nice but it overfocuses on the largest cities and not about connecting the entirety of the country. I’ve seen such criticism elsewhere, asserting that high-speed rail is a tradeoff in which the thickest connections get fast trains but the long tail suffers, whereas the medium-speed system of Germany or Switzerland or Austria serves everyone. So with that in mind, let’s look at the actual population served by a Germany-wide high-speed rail program.

I made a proposal last year, but then made some additional tweaks, posted as part of a Europe-wide map. The most important tweak: the main east-west trunk line was extended to Dortmund, which trades off some additional tunneling in the Ruhr for both higher frequency on Berlin-Dortmund and fast, frequent Dortmund-Cologne and Dortmund-Düsseldorf service. To my later map I’ll add one proposal: moving the Hanover-Dortmund tracks so that trains can stop in Bielefeld. Otherwise, take the maps as given.

The question is, what population is served by those maps? The answer of course depends on what this exactly means. The sum total of the populations of the cities served – Berlin, Hamburg, Hanover, Dortmund, Würzburg, Erfurt, Mannheim, etc. – is 18.2 million, or 21% of Germany’s population. But is that the full story? This just includes central cities, where people in many nearby suburbs and satellite cities would travel to the rest of the country via the primary city center anyway.

For example, let’s go down this list of German cities. The largest city without a stop on my proposed network is Bonn. But Bonn is very close to Cologne and there are Stadtbahn subways connecting the two cities, in addition to regional rail lines; Bonn also has a shorter-range Stadtbahn to a suburban station at which some high-speed trains on the Cologne-Frankfurt line call. Is it really correct to say Bonn is unserved? Not really. So its population should be added to the 18.3 million.

Going down the list, the same can be said of Wiesbaden (near Frankfurt), Mönchengladbach (Düsseldorf) and likewise many Rhine-Ruhr cities, Halle (near Leipzig and potentially on some slower Berlin-Erfurt trains like today), Potsdam (near Berlin), Ludwigshafen (near Mannheim), and many others. Some cities remain unserved – the largest is Münster, like a few other northwestern cities not really near anything bigger or on any line – but overall this adds another 5.3 million. So we get 23.6 million, around 30% of Germany’s population.

But that list is just cities of 100,000 people or more, and there are smaller suburbs than that. These form counties (“Kreise”), which should be added as well when feasible, e.g. when they lie on S-Bahn systems of large cities or when they are right across from cities with stations, such as Neu-Ulm to Ulm. For example, the Kreise served by the Munich S-Bahn, excluding the city proper, have a total of 1.3 million people, and people in those suburbs would be connecting to the rest of Germany by train at Munich Hauptbahnhof anyway – a lower-intensity, higher-coverage network would do nothing for them.

Overall, these suburbs add another 18.7 million people. In Berlin I used this list of suburbs; elsewhere, I went by S-Bahn reach, or in a few cases used an entire region where available (Hanover, Göttingen, Fulda). There are a few quibbles on the margin in the gaps between the Frankfurt and Rhine-Neckar and in places that probably should count but aren’t on any big city S-Bahn like Frankfurt an der Oder, but it doesn’t change the big picture: a dedicated high-speed rail network would serve around half of Germany’s population pretty directly.

Very little of the remaining half would be genuinely bypassed the way Magdeburg and Brunswick were when Germany built the Berlin-Hanover line. Regensburg, for example, is and will remain peripheral under any rail plan, with regional connections to Ingolstadt and Nuremberg; high-speed rail serving those cities is the best way to connect it to destinations beyond Bavaria. Kiel, at the other end of the country, is and will always remain connected to Hamburg by regional rail. Münster, genuinely unserved, is not really bypassed, not with how close it is to Dortmund. And so on.

Such a plan cannot serve the entire country, but it can definitely then serve a majority of it. It mostly serves the largest metropolitan areas, but that’s fine – Germany is an urban country, around 40% of the country lives in metro areas of at least 1 million people (defined again mostly by S-Bahn reach, which is a conservative definition by American MSA or French aire urbaine or Japanese MMA standards) and much of the rest is either in metro areas somewhat below the cutoff or in exurbs served by regional trains but not the S-Bahn.

Public Transportation in Megacities

I’ve been talking so much lately about integrated timed transfer in the context of Boston that people started asking me if it’s also applicable to New York. The answer is that the basic principles are not scale-dependent, but the implementation is, so in very large cities, public transport planning should not look like in Switzerland, a country whose largest metro area is staring at 2 million people from the bottom.

The one caveat here is that most cities are not huge. The developed world has seven megacities: Tokyo, Seoul, New York, Los Angeles, Osaka, London, Paris. And Los Angeles doesn’t really have public transportation, so we’re down to six. The middle-income world has a bunch more for sanity checking – Mexico City, São Paulo, Rio de Janeiro, Buenos Aires, Johannesburg, Moscow, Istanbul, Tehran, Beijing, Shanghai, Guangzhou, Shenzhen, Bangkok – but all are either still in convergence mode building up their networks or (mostly in Latin America) have given up. So much of this comes down to the idiosyncrasies of six cities, of which the largest three networks are substantially in the same planning tradition.

Demand is huge

Big cities have big centers, which can’t really be served by any mode except rapid transit. Even in Los Angeles, what passes for a central business district has around a 50% public transport modal split. This means that the transport network has to deliver high throughput to a relatively small city center. Even in a low-kurtosis city like Paris, most Métro lines converge on a narrow area ranging from Les Halles to Saint-Lazare; in a high-kurtosis one like New York or Tokyo, there are a few square kilometers with 200,000 jobs per km^2, which require an exceptionally dense network of rapid transit lines.

Some other network design principles follow from the need to amply serve city center. Specifically, high frequency is rarely a worry, because there’s so much demand even off-peak that usually megacity subway systems do not venture into the frequency range where long waits deter traffic; New York’s 10-minute midday gaps are bad, but that’s unusual and it comes from a combination of the legacy of postwar fear of subway crime suppressing demand and excessive branching.

But other principles require careful planning still.

Electronics before concrete, megacity version

The driverless lines in Paris support peak throughput of 42 trains per hour – a train every 85 seconds. CBTC on Line 13 without driverless operation supports 38 tph, and London’s CBTC-equipped lines support 36 tph when the branching isn’t too complex. It is imperative for other cities to learn from this and do whatever they can to reach similar headways. The difference between 21 tph, as in Shanghai, and Paris’s 42, is equivalent to building a brand new subway line. And what’s more, in a city in the size class we’re talking about, the primary concern is capacity – coverage is already good, so there really is no reason to build two 21 tph lines instead of one 42 tph one.

The situation in Paris is in a context with self-contained lines. That said, extremely busy self-contained lines do exist in other megacities – London has a bunch with near-Parisian levels of throughput, New York has some, Tokyo has a few, Seoul and Osaka are both more self-contained than Tokyo is.

Throughput and organization

The primacy of throughput means that it’s worthwhile to build small infrastructure upgrades, even with concrete, if they help with capacity. Right now the Northern line reverse-branches with the branches to the north recombining with those in the center, and Transport for London would like to split the line in two, reducing branching complexity, which would increase capacity. But doing so requires improving pedestrian circulation in the corridors of the branch point, Camden Town, where TfL expects very large transfer volumes if there’s a split and already there are circulation problems today without a split. Hence the plan in the medium term is to upgrade Camden Town and then split.

If there are bumper tracks at the end of a line, as at 8th Avenue on the L or Flushing-Main Street on the 7, then it’s useful to dig up the street for another block just to add some tail tracks. That way, trains could enter the station at full speed. This increases throughput, because the terminal interlocking has trains heading in opposite directions crossing each other at-grade, which imposes schedule constraints; it’s best if trains can go through the interlocking as fast as possible to reduce the time they’re in a constrained environment, but that in turn requires short tail tracks so that an overrun of a few meters is not catastrophic. Ideally the tail tracks should even extend a full train length past the platform to place the interlocking on the other side of it, as is done in Paris and Moscow; in that case, trains cross the interlocking out of service, when it’s easier to control their exact timings.

Such projects are disruptive, but the disruption is very localized, to just one transfer station for a deinterlining project as in London or one terminal as in New York, and the impact on capacity is very large, if not quite as large as the full suite of signaling and track upgrades that make the difference between a train every 3 minutes and a train every 1.5 minutes.

Network design

The ideal metro network is radial. Megacities already support that just because so many lines have to serve city center. However, it’s important to make sure every pair of lines intersects, with a transfer. No large metro network in the world achieves this ideal – Mexico City’s network is the largest without missed connections, but it is not radial and its only three radial lines are overburdened while the other lines have light ridership. Paris has just a single missed connection on the Métro proper, not counting the RER, but it has many pairs of lines that do not intersect at all, such as M1 and M3. London is more or less a pure radial, but there are a handful of misses, including one without any transfer between the two lines anywhere, namely the Metropolian line (including Hammersmith and City) and the Charing Cross branch of the Northern line.

Big cities that plan out a metro network have to make sure they do better. Missed connections reduce passenger ridership and lead riders to overload the lines that do get connections; for example, in Tokyo one reason cited for the high ridership of the Tozai Line is that until Fukutoshin opened it was the only one with a transfer to every other subway line, and in Shanghai, Line 1 was extremely congested as long as the alternatives going north either had critical missed connections (like Line 8) or avoided city center (like Line 3).

The role of regional rail

Regional rail as a basic concept is mostly scale-invariant. However, the design principles for trains that come every half hour are not the same as those for trains that come every 5 minutes. If trains come every half hour, they had better connect cities in a roundtrip time equal to an integer number of half hours minus turnaround times, so that they don’t have to loiter 25 minutes at a terminal collecting dust and depreciating. If they come every 5 minutes, they’re not going to loiter 25 minutes anyway, and the difference between a 5-minute turnaround and a 7-minute turnaround is not really relevant.

The design principles are then mostly about throughput, again. The most important thing is to build independent trunk lines for trains to serve city center. Even in a huge city, the finances of building a purely greenfield subway deep into suburbia are poor; Tokyo has done it with the Tsukuba Express but it’s mostly above-ground, and for the most part regional lines there and elsewhere come from taking existing suburban lines and linking them with city center tunnels.

Tokyo’s insistence on making these city center tunnels also form a coherent metro network is important. Only one non-Tokyo example is worth mentioning to add to all of this: this is Berlin, which is not a megacity but has three independent S-Bahn trunk lines. Berlin, unlike London and Paris, painstakingly made sure the S-Bahn lines would have transfers with the U-Bahn; its network has only one U-Bahn/S-Bahn missed connection, which is better than the situation in Tokyo, Paris, or (with Thameslink and Crossrail) London.

The role of development

All first-world megacities, and I believe also all megacities elsewhere, have high housing demand by domestic standards. All are very wealthy by domestic standards except Los Angeles, and Los Angeles is still incredibly expensive, it just doesn’t have the high wages to compensate that London and New York and Paris have. In such an environment, there’s no need to try to be clever with steering development to transit-oriented sites. Anywhere development is legal, developers will build, and the public transport system has a role to play in opening more land for more intense development through fast trips to the center.

A laissez-faire approach to zoning is useful in such an environment. This contrasts with smaller cities’ reliance on finger plans, like the original one in Copenhagen or the growing one in and around Berlin. No limits on development anywhere are required. The state’s planning role remains strong through transportation planning, and the suburbs may well form natural finger plans if developers are permitted to replace single-family houses with apartment buildings anywhere, since the highest-value land is near train stations. But state planning of where housing goes is counterproductive – high transit ridership comes from the impossibility of serving a large central business district by cars, and the risk of politicization and policy capture by homeowners is too great.

The advantage of this approach is also that because in a high-demand city public transport can to some extent shape and not just serve development, it’s okay to build lines that are good from the perspective of network coherence, even if the areas they serve are a bit light. This principle does not extend indefinitely – subway and regional rail lines should still go where people are – but for example building key transfer points in near-center neighborhoods that are not in high demand is fine, because demand will follow, as is building lines whose main purpose is to close some gap in the network.

Construction costs

The larger the city, the more important cost control is. This may sound counterintuitive, since larger cities have more demand – only in Manhattan could a $1.7 billion/km extension like Second Avenue Subway pencil out – but larger cities also have a bigger risk of cost blowouts. Already Tokyo has stopped building new rapid transit in the core despite very high crowding levels on the existing network, and London builds next to nothing as well. New York’s poor cost control led Philip Plotch to entitle his book about Second Avenue Subway The Last Subway. Even Paris builds mostly in the suburbs. Extensive city center and near-center construction continues in Seoul, in the context of very low construction costs.

The flip side is that a New York (or even London) that can build subways at the cost of Paris, let alone Seoul, is one that can rapidly solve all of its transport problems. My Assume Nordic Costs map fixates on a region of the world with small cities, but the construction costs in South Korea are if anything lower than in the Nordic countries. And even that map, given free reins for developers, is underbuilt – some lines would look ridiculous at current costs and zoning but reasonable given low costs and liberal zoning, for example something meandering through currently industrial parts of New Jersey.

Small cities designed their public transportation philosophy around scarcity: Switzerland really can’t just draw crayon and build it, because housing and transport demand there are finite and limited. Cities like New York and London, in contrast, should think in terms of abundance of infrastructure and housing, provided their regulations are set up in a way that permits the state to build infrastructure at low costs and private homebuilders to redevelop large swaths as they become easily accessible to city center.

Cities With Underbuilt Public Transportation

There’s a number of very big cities in middle-income countries that don’t really have strong public transport, and I’d like to go over some of their features. The archetype for this urban form is Bangkok, but I think this is pretty common in much of Latin America too, it’s ubiquitous in Southeast Asia except in Singapore, and Cairo has it too and I suspect most of the rest of Africa will as it moves into the middle income category. I’m fairly certain in what I am saying as far as Southeast Asia is concerned, following Paul Barter’s thesis; in Turkey I am less certain, and in Latin America and Egypt I am speculating. Of note, while those regions have some shared features, one feature that is not shared is cost: while Southeast Asian construction costs are very high, Latin American ones are not, and Turkish ones are very low. Of course low costs enable Turkey to build more subways, but it’s only doing so right now as it’s converging to the high income category.

Density with cars

Bangkok is a dense city. It is not to be confused with Hong Kong, but it is not to be confused with Atlanta either. That said, the density has not much structure, similar to the situation of Los Angeles – there is no single central business district, just a big central area with sub-districts with high-rise office and residential towers. Private vehicle ownership is high, and as of 2014, the modal split (source, PDF-p. 44) was 58% car and motorcycle (trending up), 37% bus (falling rapidly), 5% metro (trending up).

My understanding is that this pattern is also how cities like Manila, Lahore, Karachi, and Jakarta look, and even São Paulo, which has a decent-size metro system with pretty high ridership but it’s still undersized for how big the region is. Dhaka (which is low- rather than middle-income) and Cairo have especially high residential densities.

Slow metro expansion

All of these cities are building urban rail, but not particularly quickly (except Istanbul, where costs are unusually low). Bangkok is adding a few lines, but even under current plans will keep having an underbuilt system. The same is true for plans in Manila, Jakarta, Lahore, Cairo, and low-income Dhaka. In most of Latin America, too, expansion is pretty slow – the only city where I’ve seen really fast expansion recently relative to size is Santiago, which is both approximately the richest in the region and also has below-average construction costs.

The slow construction is an important feature. Some cities build quickly and can transition toward reliance on public transport. For example, Taipei only began building its MRT network in the 1990s, long after the most similar capital city to it in overall development history, Seoul, had had a multi-line network. It was a city of motorcycles in the 1990s and so were the other Taiwanese cities, but through fast (albeit expensive) construction has become a transit city, developing higher-intensity central business districts at key MRT junctions and turning its older unstructured density into a structured one.

I am also excluding India from this analysis for the same reason. Indian cities are making enormous mistakes in metro construction, chief of which are poor integration with suburban rail and high construction costs, but they are building, and even keep a lid on costs by building mostly elevated systems. The Delhi Metro ridership is flagging, but it’s a big system, about the same size as New York or London, and it’s expanding quickly; the rest of India is still only catching up, but the plan for Mumbai in 10 years is extensive. Tehran is in the same basket as Indian megacities, judging at least by its healthy pace of metro expansion.

Car domination

Even when most people do not own cars or even motorcycles, as was the case in Thailand until recently, the government prefers cars to public transport. This comes from the fact that unless the public transport is excellent, or only serves where the middle class works, richer people will use cars more than poorer people, and tilt government policy to their preferences. Lagos, for example, was seriously considering banning its jitneys in 2017, called danfos, even as car ownership was 150 per 1,000 people, and has periodically considered such a ban a few times since.

This domination exists even in very poor cities. Years ago, a cousin who was visiting Kampala described its traffic to me as a brutal pecking order in which cars fear trucks and pedestrians fear cars. If 5% of the population owns cars, that’s still the richest 5%, and they get to dictate the rules.

Is it governance?

Something most of those cities I’m describing have in common is a form of government called anocracy. It’s defined as an intermediate form between democracy and autocracy, but really should mean a system in which there is unclear authority – perhaps there are elections but they are not truly free, perhaps there is a deep state, perhaps there is a dictator but the dictator’s power is circumscribed by powerful magnates and norms that do permit some political criticism. Anocracies tend not to have very strong states – a strong state under a dictator rapidly becomes a stable autocracy, for example Russia’s transition to autocracy in the last 20 years under Putin, whereas a strong democratic state evolves enduring norms and institutions of civil liberties and pluralism, like Taiwan and South Korea starting in the 1990s.

I suspect there may be a connection here: anocracies do not really have the state planning ability to restrain local magnates, like these top 10-20% of the population who are drivers. They can build roads, because it takes much less state capacity to incrementally expand roads, often with local sponsorship, than to plan a multi-line metro system, let alone do the clever multimodal design integration between infrastructure and timetabling that Switzerland does.

This is not a perfect correlation. Egypt is autocratic and not anocratic, although its recent military coup suggests it may not be as stable as autocracies with full civilian control of the military like Russia and China. Vietnam appears even more stable, and showcased high state capacity through excellent management of the corona crisis (though coup-ridden Thailand has had an excellent response as well). Moreover, there is no correlation between anocracy and construction costs – even putting my finger on the scales and classifying Turkey as not-anocratic, the correlation between a dummy that takes the value 1 at what I think are non-Turkish anocracies and construction costs is 0.06.

That said, there may be something to the fact that we see rapid expansion of metro systems in a developing country with relatively strong democratic institutions, i.e. India, and saw such expansion in turn-of-the-millennium Taiwan, and likewise we also see rapid expansion in relatively stable autocracies like Iran and China, but we see much less of it in countries without strong governments. And Moscow’s fast metro growth in Russia’s anocratic phase in the 1990s and early 2000s can be excused as having some strong-state planning institutions, inherited from the USSR. Egypt in contrast never had these institutions, with its imperfect state control of the military.

Low- and Medium-Cost Countries

I was asked a very good and very difficult question in comments yesterday:

What, specifically, are the best practices we all should be learning from the lower cost countries? I’m reading a lot of what not to do, but not on what do to.

I’ve gone a lot over bad industry practices leading to high costs in the Anglosphere, especially the United States, especially New York, and to some extent also on bad practices in developing countries like India. These I am contrasting with a set of good practices from a host of low-cost countries like Spain and Italy as well as medium-cost ones like Germany and France.

However, the question remains, what distinguishes low- and medium-cost countries? The differences between them are not small – underground rail extensions in German cities are averaging around 250 million euros per kilometer, and ones in French cities are around 200 million or just less than that, whereas Milan and Turin average around 100 million, and Spanish cities average even less. Germany is a higher-cost and higher-wage country than Italy and Spain, but Berlin wages are not higher than Madrid and Milan wages, and within these countries, richer cities don’t really have higher costs (Milan is cheaper to tunnel in than Naples, Madrid has lower costs than Barcelona and similar costs to the rest of Spain, the cheapest German tunneling seems to be in Hamburg of all places). No: this is almost certainly a real difference in institutions that enables Southern Europe, Scandinavia, South Korea, and Turkey to dig tunnels at one third to one half the cost of Germany.

This argues in favor of doing a deep dive case on a medium-cost example like Paris or Berlin, in addition to the work we’re doing on low-cost Milan and Istanbul. The problem is that it’s not clear, so far, what to even look at. I have a decent idea of what the difference between the high-cost world and the rest of the world is – but applying it to the low- and medium-cost world is dicey.

In-house engineering capacity

So much of the problem in the Anglosphere seems to come from the loss of in-house engineering capacity, and its replacement with private consultants. The latest iteration of this is the penchant for design-build contracts, in which the state contracts with one company to handle the entire process and doesn’t have much if any public-sector oversight. Design-build doesn’t exist in any of the countries in Continental Europe I have any familiarity with; France is looking into it as a reform in the future, but only under the aegis of a large public-sector planning team coordinating the private-sector design and construction. Moreover, Canada’s recent adoption of design-build, coming from an ideology imported from Britain and then falsely claimed to come from Madrid, preceded an explosion in costs.

However, this does not really explain the difference between France or Germany and Scandinavia or Southern Europe. Norway and Spain have separation of design and construction; so does France. Italy and Spain have in-house engineering teams responsible for a great deal of the design, but to some extent France does too, with a large in-house planning team overseeing the private-sector designs.

Procurement issues can’t really distinguish the low- from medium-cost world either. Madrid does not hand out lowest-bid contracts – at least in its big wave of expansion in the 1990s and 2000s, contracts were given 50% on the basis of a technical score marked by the in-house engineering team, 30% on that of cost, and 20% on that of how fast they could finish the project. Paris doesn’t have a 50-30-20 split but a 60-40 one; that may be significant, but I doubt it. Both systems contrast with the American system of lowest bid, or sometimes 30-70 in California. Moreover, Turkey is lowest-bid, but it’s a repeated game due to the country’s fast growth and construction – contractors who screw up do get penalized in future projects.

Citizen voice and NIMBYism

Germany has a huge problem with NIMBYism. Key segments of the national passenger rail network, for example Hamburg-Hanover, remain slow because local NIMBYs who don’t like fast trains have litigated high-speed rail to death. France has had anti-LGV NIMBYism in Provence as well, which NIMBYism is often extralegal (that is, aggrieved drivers blocking roads); this forced the state to change its plans for a high-speed railway to Nice from a mostly above-ground inland route to a tunnel-heavy coastal route through the Maritime Alps and, as the cost was prohibitive, eventually downgrade into a mixture of high- and low-speed rail line.

As I understand it, this is less of an issue in Southern Europe. I do not know to what extent it’s a problem in Scandinavia and Switzerland; Switzerland does have a lot of bucolic NIMBYism, where “bucolic” means “the city as it looked in 1957,” but I don’t think it’s had any that successfully scuttled infrastructure, and overall the political imperative there seems to reduce costs more than anything.

The NIMBY issue is also important in the US and UK. In the US, NIMBYs are not legally strong, but politicians prefer to avoid the appearance of controversy and therefore give local actors whatever they ask for, no matter the cost; many sources told Eric and me versions of this story regarding the high cost of stations on the Green Line Extension (which are, to be clear, maybe 20% of the cost of the whole project). Brooks-Liscow favor this explanation for the internal increase in the cost of highways in the US from the 1970s onward.

I do not know to what extent there’s an institutional explanation here. I do not even know if this is a real difference between on the one hand France, Germany, Austria, the Netherlands, most of the 2004-7 EU accession countries, and Japan, and on the other hand Southern Europe, Bulgaria, Turkey, and South Korea. It’s possible that this is a bigger problem in Northern Italy than I realize.

The most worrying possibility is that this is a real difference, and it comes not from something about institutions, but from surplus extraction. The European core and Japan are rich, and at $150 million/km, subways there would create immense social surplus and decent financial surplus. (The Japanese state is refusing to build at $500 million/km because it wants a 30-year financial payback). Southern Europe is less rich, so there is less social surplus to extract by local actors wanting to dip their beaks in state money; Switzerland and the Nordic countries are rich, but their cities are smaller and farther-apart, so there is less surplus there too.

There are a lot of objections that can be raised to the surplus extraction hypothesis: there is plenty of surplus in Seoul and not much in Vienna or Prague or Bucharest or Warsaw or Tel Aviv, Japan already reached $250 million/km in the 1970s when it was a lot poorer than Korea is today, the surplus hypothesis predicts that there should be higher costs in richer cities within the same country and yet this is not observed, local interference with Métro expansion in Paris unlike with LGVs doesn’t seem very significant.

Conclusion

There’s no good answer to what distinguishes low- from medium-cost countries. I wish more people here and in France were interested in this question – the activist sphere in Berlin seems far more interested in trams and bike lanes than in rapid transit. Nor do I imagine Germans and French are ready to hear that there’s something the Italians and Spaniards and Turks do better than they do. But it’s something Germany is going to need to learn to deal with if it wants better infrastructure; on the same budget, it can get 2-3 times as much as it’s getting now.

Integrated Timed Transfer Schedules for Buses

I’ve written a bunch about integrated timed transfer (ITT) scheduling based on Swiss and Dutch principles, developed for intercity and regional trains. Here, for example, is how this schema would work for trains connecting Boston and Worcester. But I’ve also seen interest in how buses can connect to one another, so I feel it’s useful to try to adapt the ITT to this different mode. Two particular places where I’ve seen this interest are a statewide plan for intercity buses in West Virginia, and regional integration around Springfield and the Five Colleges; I’m not going to make specific recommendation for either place, since I don’t know them nearly well enough, but I hope what I write will be helpful there and elsewhere.

The ITT principles for trains

ITT for trains relies on total coordination of all aspects of planning. The centerpiece of this is the triangle of infrastructure, rolling stock, and timetable, all of which must be planned together. Decisions on infrastructure spending should be based on what’s required to run the desired schedule, based on tight turnarounds, maximal utilization rates of equipment, and timed connections.

The even broader principle is to trade state complexity for money. It’s harder to plan everything together – different departments need to talk to one another, planning has to be lean or else the back-and-forth will take too long, regulations may have to be adjusted, government at all levels has to push in the same direction. The reason to do this chore is that it’s far cheaper than the alternative. Organization is cheaper than electronics and concrete at all levels; American households spend around 20% of their income on transportation, mostly cars, whereas households in transit cities like Paris or Berlin or Tokyo spend a fraction of that, even taking into account residual car ownership and operating subsidies to public transit.

On buses, there’s no such thing as electronics…

The Swiss maxim, electronics before concrete, concerns trains exclusively. On buses, no such thing exists. It’s not really possible to get higher-performance buses to make a more aggressive schedule. Acceleration rates depend on passenger safety and comfort and not on the motors (in fact, they’re higher on buses than on trains – rubber tires grip the road better than steel wheels grip rails). The closest analog is that electric buses are lower-maintenance, since the diesel engine is the most failure-prone part on buses as well as trains, but what this leads to, IMC, is not really a strategy for improving timetabling – IMC’s main benefits are less pollution and lower maintenance costs.

…but there is a surplus of organization to be done

All the little things that on trains go in the electronics bucket go in the organization bucket on buses. These include the following operating treatments to improve local bus speeds:

  • Off-board fare collection
  • Stop consolidation to one every 400-500 meters
  • Dedicated lanes in congested areas
  • Signal priority at busy intersections

In addition, bus shelter does not increase actual speed but does increase perceived speed, and should be included in every bus redesign in an area that lacks it.

These are all present in Eric’s and my Brooklyn bus redesign proposal, but that doesn’t make that proposal an ITT plan – for one, it’s based on 6-minute frequencies and untimed transfers, whereas ITT is based on half-hour frequencies (for the most part) and timed transfers. Of note, in a 6-minute context signal priority should be conditional to prevent bunching, but if buses run on a 30-minute or even 15-minute timetable then bunching is less likely, especially if buses have prepayment and some dedicated lanes.

That said, it’s important to talk about all of the above in this context, because a bus ITT belongs in areas where public transport ridership is so low that people view a bus every 15 minutes as an aspirational schedule. In such areas, the politics of giving buses more priority over cars are harder than in a city with low car usage like Paris or New York or Barcelona. There are some positive examples, like Rhode Island’s eventual passage of a bill giving six key bus corridors signal priority, but in Tampa I was told that DOT wouldn’t even let the bus agency bump up frequency unless it found money for repaving the street with concrete lanes.

What about intercity buses?

Prepayment, stop consolidation, and dedicated lanes are important for speeding up local buses. But intercity buses already stop sporadically, and often run on highways. There, speedup opportunities are more limited.

But there may still be some room for signal priority. If the bus only runs every hour or every half hour, then driver resistance may be reduced, since the vast majority of stoplight cycles at an intersection will not interact with a bus, and therefore the effect of the change on car speed will be small.

This is especially important if buses are to run on arterial roads and not on freeways. The significance is that highways are noisy, especially freeways, and do not have the concept of a station – freeways have exits but one takes an exit in a car, not on foot. Therefore, development does not cluster near a freeway, but rather wants to be a few minutes away from it, to avoid the noise and pollution. Arterials are better at this, though even then, it’s common for American big box stores and malls to be somewhat set away from those, requiring bus passengers to walk through parking lots and access roads.

Arterial roads, moreover, often do have stoplights, with punishing cycles optimized for auto throughput and not pedestrian-friendliness. In such cases, it’s crucial to give buses the highest priority: if these are intercity buses rather than coverage service to a suburb where nobody uses transit, they’re especially likely to be full of passengers, and then a bus with 40 passengers must receive 40 times the priority at intersections of a car with just a driver. Moreover, if it is at all possible to design stoplights so that passengers getting off the wrong side of the street, say on the east side for a northbound bus if the main development is west of the arterial, can cross the street safely.

Designing for reliability

The principles Eric and I used for the Brooklyn redesign, as I mentioned, are not ITT, because they assume frequency is so high nobody should ever look at a timetable. But the ITT concept goes in the exact opposite direction: it runs service every 15, 20, 30, or even 60 minutes, on a consistent clockface schedule (“takt”) all day, with arrival times at stations given to 1-minute precision.

Doing this on a bus network is not impossible, but is difficult. In Vancouver, the bus I would take to UBC, the 84, came on a 12-minute takt off-peak, and ranged between on time and 2 minutes late each cycle; I knew exactly when to show up at the station to make the bus. When I asked Jarrett Walker in 2017 why his American bus redesigns assume buses would run roughly every 15 minutes but not on such a precise schedule, he explained how American street networks, broken by freeways, have more variable traffic than Vancouver’s intact grid of many parallel east-west arterials.

So what can be done?

Dedicated lanes in congested areas are actually very useful here – if buses get their own lanes in town centers where traffic is the most variable, then they can make a consistent timetable, on top of just generally running faster. Signal priority has the same effect, especially on arterials as noted in the section above. Moreover, if the point is to make sure the noon timetable also works at 8:30 in the morning and 5:30 in the afternoon, then driver resistance is especially likely to be low. At 8:30 in the morning, drivers see a bus packed with passengers, and their ability to argue that nobody uses those bus lanes is more constrained.

Learning Worst Industry Practices

If I have a bad idea and you have a bad idea and we exchange them, we now have two bad ideas.

But more than that. If I have a bad idea and you have a good idea and we exchange them, we should both land on your good idea – but that requires both of us to conceive of the possibility that your idea could in fact be better than mine. This is not always the case. In exchanges between Britain and Australia, both sides think of Britain as the metropole and Australia as the periphery, so ideas flow from Britain outward. The same is true in exchanges between either Britain or the United States and Canada.

We even see this in exchanges between the Anglosphere and the rest of the world. Europe knows what the United States is like. We speak English and read American news to some extent. We have occasional sympathy protests with American causes that we feel are reflected at home; I have never seen Americans do the same with people outside North America except for very small protests concentrated among a particular diaspora, such as small groups of Israeli-Americans protesting Netanyahu’s policies in front of Israeli consulates.

And most of us in Europe look at the United States with a combination of denigration and disgust, but it’s not everyone, and in a pandemic, the least responsible members of society set everyone’s risk levels. There’s been some American influence on the populist right in Europe – people who see Trump and think “we would like to be governed like that”; this is still sporadic, e.g. the Gilets Jaunes used French populist language and had no connections to the United States, but the corona denialist protests in Germany have imported some American language like QAnon symbols. And more broadly, seeing other countries fail emboldens the pro-failure caucus at home: the Israeli immigrant who told me 2 months ago that “800 cases a day is nothing” Germany-wide would probably not have said this if Israel maintained its May infection rates. Of course the vast majority of denialists here are not Israeli or Jewish, and many are even anti-Semitic, but they look up to the failure that is the United States and not to the one that is Israel.

The corona example above is specific to Germany and is a bad idea that remains a minority position in Germany, but good ideas from the United States have made it to Europe elsewhere. For example, France made it easier to start a business, to the point that incorporation takes a few days and 4,000 euros in a corporate account, regulations on small business are very friendly, and there is elite consensus in favor of making hiring more flexible and some movement in that direction in the Macron administration. On handling racial diversity, Europe is sporadically importing ideas from the US, some good, some terrible, but again there is little attempt at learning in the other direction even when our cops kill a few dozen people per year Western Europe-wide and America’s kill 1,000.

I bring this up, because in transportation, one sees a lot of learning of practices both good and bad, if they come from a higher-prestige place. I may even speculate that this is why the most culturally dominant part of the world has the worst institutions when it comes to building infrastructure: if New York were capable of building something for one eighth the cost of Paris or one sixth that of Berlin, instead of the reverse, then Paris and Berlin would be capable of learning to adopt New York’s institutions.

To speculate even further, this may be why the cheapest place to build subways in East Asia is not Japan but Korea – if Japan were the best, South Korea would have learned from it. There are extensive similarities between these two countries’ institutions in general and urbanism and transportation in particular, coming from one-way learning of Japanese ideas in Korea more than from reciprocal learning. Evidently, Korea first of all learned from Japan that the primate city should be rail-oriented rather than car-oriented, and subsequently learned Japan’s extensive integration of urban rail with regional rail, its combination of local and express trains, its interest in rail technologies other than conventional subways, and so on. If Tokyo and Osaka were capable of building $120 million/km subways, Seoul would’ve picked that up. Instead, Seoul can do this but Tokyo and Osaka are evidently not learning.

In Europe, the same pattern holds. None of the most culturally dominant countries here has low costs. France and Germany’s construction costs are very average by global standards and on the high side by Continental European ones, and both have serious problems with how long it takes to build infrastructure projects. The stars of high-quality, low-cost construction in this part of the world are Southern Europe, Turkey, Switzerland, and Scandinavia. The first two are ridden by cultural cringe – nobody there other than a few railfans believes that they’re capable of doing better than Germany. And evidently, where Germany and France outperform Spain, for example in high-speed rail ridership, the Spanish discourse understands this and tries to correct the situation.

Switzerland and the Nordic countries are dicier, since they are rich and well-governed and everyone in Europe knows this. People in France and Germany even reference various Nordic models as examples to learn from, and, in contrast, the Nordic countries’ willingness to learn from non-Nordic examples is limited. However, these are all small countries that import culture more than exporting it. The vast majority of German culture is produced in Germany and not Switzerland; people in Germany are aware that Switzerland exists and is richer, but Germany’s size lets it get away with not learning. The Nordic countries, likewise, are small enough that other countries are not as regularly exposed to their ideas and therefore treat them as exotic more than as examples to learn from.

I bring up the issue of size, because it is so flagrant in the United States especially, and also in Britain. The US philosophy that economic or social might makes right is not done on a per capita basis, and practically every comparison to another country elicits the “we’re way bigger than them” excuse. Britain engages in the same excuse-making at every comparison to a European country smaller than Germany, France, Italy, and Spain, whereas these four it dismisses on a case-by-case basis; the Australian cultural cringe toward Britain is evidently not about per capita living standards, since Australia’s GDP per capita has been higher than Britain’s for most of the last 150-200 years, but rather about Britain’s greater size and historic status as a world power.

You may be wondering, maybe this is just a way to theorize around the fact that it really is easier to build infrastructure in a smaller country? But no. Turkey and South Korea and Italy and Spain are not small. Seoul is the second largest metropolitan area in the developed world, behind Tokyo and ahead of New York. The common factor to the lowest-cost countries in the world is not size, but rather their status on the periphery of the developed world, either economically or culturally.

Of course, peripheral status is not enough. Former colonies tend to have high construction costs, perhaps because they learn the wrong lessons from the developed world or from China. Italian wages and capital costs are by global standards approximately the same as German ones, so Italy can adapt German ideas where they’re superior, but Indian wages are so much lower and capital costs so much higher that it cannot blindly imitate Japan and expect success. In the developed world, too, we see failure, when countries learn from the wrong examples, that is Britain or the United States; Singapore has severe cultural cringe toward the Western world, but it finds it easiest to adapt British ideas out of familiarity rather than better Continental ones, in much the same way that reform proposals in the United States look to Britain and Canada rather than to Continental Europe or democratic East Asia.

The way forward must be to recognize this cringe, and know to look for ideas that do not obey the global social hierarchy. Southern Europe has a lot to teach Germany and France, and the Nordic countries are not exotic far north utopias but countries with real institutions that can be adapted elsewhere, and Turkey has a very efficient construction sector, and Korea has a lot to teach its former colonizer as well as the rest of Asia.

More to the point, the most dominant places in the world have very little left to teach others. Everyone knows what New York is like. There are many good things about New York, but we’ve done a decent job copying them. London, same thing. It’s time for New York and Los Angeles and Toronto and London to stop exchanging bad ideas and start learning from places that do not speak English as a first language, and not just from the world’s next largest language groups either.

Hong Kong Construction Costs

I think we have found the #2 city in urban rail construction costs, behind only New York. This is Hong Kong, setting a world record for the most expensive urban el and encroaching on Singapore for most expensive non-New York subway.

As we look for more data to add to our transit costs website, I looked at Hong Kong to see what was going on. I remembered that its costs were high, but didn’t remember details – I think the project I was thinking of was the longest, the Sha Tin to Central link, but I looked at all recent, under construction, and planned MTR lines. I summarized the results on Twitter, but I’d like to cover this in more detail here.

The projects and their costs

Tung Chung Line extension: a planned line for construction in 2023-30, a total of 1.8 km underground, HK$18.7 billion, or around US$3.1 billion, or $1,730 million per km. Even giving it 1.8 km seems like I’m doing Hong Kong a favor – the extension is 1.3 km, and the other 500 meters are overrun tracks at the Hong Kong Island end, which I don’t ever count elsewhere since it is not in-service trackage. In addition to the tunneling (and single underground station), there is a single at-grade infill station, whose contribution to the budget is approximately zero.

West Island Line: 3 km underground, HK$18.5 billion. This is around US$3.4 billion, or $1,130 million per km. Only six lines globally are more expensive than this: phase 6 of the Circle line in Singapore, and the five New York lines, of which three are not even open yet. This is not even regional rail, but construction is entirely within the Hong Kong CBD, explaining why it is so expensive even by local standards.

Sha Tin-Central: 17 km, HK$87.3 billion, or around US$14.5 billion. This is $850 million per km. The line is not even fully underground, just 90%: the northernmost segment, totaling around 10%, is elevated. This line near-ties Crossrail and the Melbourne Metro Tunnel for most expensive line in the world longer than about 5 km – New York is building short lines, the longest (Gateway) around 5 km depending on source. The line is partially regional rail: it includes a 6 km extension of the East Rail Line under Victoria Harbour toward Admiralty, but the other 10 km is not regional rail.

Tuen Mon South Extension: 2.4 km, HK$11.4 billion, all elevated, in an outlying residential area. This is $790 million per km, making it the world’s most expensive el – New York’s most recent els, the JFK and Newark Airport connectors, were positively reasonable by this standard, only around $270 million/km adjusted for inflation (but don’t worry, the PATH estimates in the near future are a lot worse).

Kwun Tong Line extension: 2.6 km, HK$7.2 billion (same source as West Island). This is around US$1.3 billion, or $500 million per km. It’s the standard high cost of projects around the world, common for regional rail tunnels and CBD tunneling, except that this is strictly on the Kowloon side without as much older infrastructure to cross – it even misses a connection to the East Rail Line.

South Island Line (East): 7 km, HK$16.9 billion, around US$3 billion – see same source as West Island, or SCMP reporting. This is $430 million per km. This is not a fully underground line: as explained here, 2 km is on viaduct, serving Ap Lei Chau. Notice also that the original cost estimate was HK$7 billion, but by the time construction rose the budget had risen to $12.4 billion, and the final budget was $16.9 billion.

Is Hong Kong in the Anglosphere?

I’ve argued before that the single biggest predictor of an urban rail project’s cost is whether it is in the Anglosphere – the correlation of an Anglosphere dummy in our database is 0.54, more than even whether the project is underground or elevated. So it’s worth asking, is Hong Kong in the Anglosphere? There are arguments both ways, but I believe the preponderance of evidence points to yes.

  • Hong Kong was under British rule until 1997.
  • The legal system is traditionally based on English common law, even if there’s been a recent shift toward Chinese law.
  • There is extensive exchange of knowledge with the core (white) Anglosphere, with managers who’ve moved around like Jay Walder, political leaders who have second passports in the UK (like Carrie Lam) or sometimes Canada or Australia, and Anglo media that reprints MTR press releases about its property development model.
  • The design layout of the MTR has obvious British influences, including for example the use of cross-platform transfers between the core lines. Similarities with China are the result of convergent evolution (China is influenced by the USSR, which was influenced by Britain). There are some similarities with Japan, like the smartcard system’s use as electronic money, but they are smaller.
  • Hong Kong’s love of privatization and high inequality is very Thatcherite. Again, the similarities with Japan are smaller – Japan’s privatization is slower, and Japanese corporations rely on mutual obligations whereas Hong Kong (like Singapore) expects brutal working hours of employees without offering them lifetime employment in return.

The one non-British aspect of the MTR is its use of property development subsidies (and before anyone asks: no, the costs above are just infrastructure, not property development). MTR expansion is funded by a mixture of property development, for which the MTR receives land at below-market rates, and more direct subsidies.

However, this is still more an Anglo aspect than an Asian one. Democratic East Asia notably does not give corporations land for below-market prices, not in the 21st century. Moreover, the British fascination with the Hong Kong model, which fascination is not present in France or Germany or probably anywhere else with reasonable construction costs and democratic constraints on the state, suggests that the elites in Britain and the US would like to be governed this way, just as many would like to be governed by the Lee clan. There is, in contrast, almost no curiosity about democratic East Asian governance, even after that 200 million people region proved itself to deal with corona better than any other.

Corona is a little awkward to bring in because Hong Kong’s infection numbers look like those of an East Asian democracy (it has the civil service of one), whereas the most similar country to Hong Kong on most matters, Singapore, has those of a Gulf state full of indentured migrant workers who got infected at extremely high rates. But for engineering, it doesn’t seem terribly important what the immigration numbers are – for example, Sweden and Norway are extremely similar to Finland even though they have way more immigrants, and likewise Saudi Arabia is similar to the other, immigrant-heavier Gulf states. So overall, Hong Kong’s public transport situation can be seen as very similar to Singapore’s – and Singapore has very high costs as well.

What does this mean?

I don’t know. Singapore and Hong Kong’s costs are probably higher than those of the core Anglosphere, but I am uncertain – Singapore’s big projects are not unusually expensive by Canadian or British standards, and the Sha Tin-Central link is legitimately difficult, the kind that Sweden would build for $250 million/km rather than for $130 million/km. So it’s hard to tell whether there is something about Hong Kong that goes beyond standard Anglo dysfunction.

I do not know what Hong Kong’s historic costs were. I expect them not to be so high – Singapore’s weren’t through phases 1-5 of the Circle line, and only exploded with the Downtown and Thomson lines, and Canada’s only exploded in the late 2000s and 2010s as it decided to privatize state planning and adopt design-build contracting.

However, in the present and near future, Hong Kong is a model to study purely for its failures, much like Singapore. The leaders of Hong Kong, in their rush to emulate Chinese repression tactics, should perhaps also learn something from Chinese construction techniques – or, ideally, Korean ones, Korea being the only Asian country among the world’s cheapest. People in other countries should aim to study Hong Kong’s infrastructure construction as an example to avoid, and not one to emulate.

The Costs of Subways and Els

I’m probably going to write this up more precisely with Eric and send this to a journal, but for now, I’d like to use our construction costs database to discuss the cost ratio of subways to elevated lines. The table I’m working from can be found here; we’re adding projects and will do a major update probably at the end of the month, but I don’t expect the new data to change the conclusion. Overall, the data is consistent with a subway : el cost ratio in the 2-2.5 range, but it’s not possible to get more precise estimates despite the breadth of the data.

Crude averages

Our database has 11,559 km of total length, but not all of that comes with cost estimates yet; subtracting lines for which we don’t have costs, we get 11,095 km. The total cost of all the lines in our database is, in PPP-adjusted but not inflation-adjusted dollars, $2.302 trillion, for an average of $207 million/km. Nearly all of the items are recent – the majority by length are still under construction, and only 10% opened by 2010. So inflation adjustment is minor, though nontrivial.

Moreover, looking only at 100% underground lines, we get 3955.3 km, for a cost of $945.3 billion, averaging $239 million/km. The other lines are mixed or elevated. The purely elevated lines total 2490.4 km, for a cost of $408.1 billion, or $164 million.

To be slightly fancier but use the same underlying data, the linear estimate of cost per km, treating the tunnel proportion as the independent variable, is 153.1406 + 117.5787*tunnel-proportion; this has a larger spread than just averaging pure subways and pure els, coming from both the inclusion of more data and from not weighting by line length.

However, even the larger spread has a subway : el cost ratio of 1.77, lower than found elsewhere in the literature. Why?

Els are disproportionately build in higher-cost countries

The most important quantitative fact coming out of the analysis of construction costs is that the most important independent variables are country-level dummies. The correlation between the tunnel proportion and cost per km is just 0.163; the correlation between cost per km and a dummy variable that takes the value 1 in the US, Canada, Britain, Australia, New Zealand, and Singapore and 0 elsewhere, is 0.543. If we instead set the dummy variable to take the value 1 in the countries I consider cheap – Spain, Portugal, Italy, Greece, Bulgaria, Switzerland, Sweden, Norway, Denmark, Finland, Turkey, South Korea – then the correlation with plain cost is -0.18, and since linear correlation is better at detecting high outliers than low-but-positive ones, we can take the reciprocal of cost and then the correlation is 0.258.

So it’s useful to figure out where the most els are being built. For example, China has 5,933 km in our database – that is, a slight majority – of which 3,851 are confirmed tunnel and another 1,046 are unconfirmed (Hangzhou in particular is bad about reporting tunnel proportions). Excluding lines with unconfirmed information, we have 9,842.6 km of which 6,436.4 are in tunnel, or 65% – but China is 3,851/4,887, or 79%.

In the lowest-cost countries, els are not common. In Spain, 205.7 km out of 253.8 in our database are underground, or 81%. The Korean lines in our database are 100% underground, and as we add more data, this will hardly change. Overall, the countries I consider cheap have 927 km of rapid transit in the database, which number will rise as we add more Korean data, and of those, 730.1 are underground, a total of 79%. What’s more, one third of the non-underground length in cheap countries consists of a single 63 km item, tagged CR3, consisting of surface improvements for Marmaray (the tunnel is costed separately, as BC1); 63 km is hefty, but as a single item, it is less visible to unweighted correlation estimates like the regression.

So if els are uncommon in China and in cheap countries, where are they common? The answer is high-cost developing countries and Gulf states. India has 1,046.7 km in the database, of which only 235.8 are underground, or 23%; when I continue my series of posts on rapid transit traditions and get to India, I will of course mention the predominance of els. Moreover, these Indian els are spread across many items – there are 29 Indian items, since individual lines in Mumbai and phases in other cities each get their own lines, which matters for unweighted correlation estimates. Similarly, Thailand is 20% underground, Vietnam 50%, Pakistan’s single line 6%, Bangladesh 48%, the Philippines 55%, Malaysia 22%, Indonesia’s single line 38%, Panama 12%, Saudi Arabia 14%, the UAE 22% – and all of these are high-cost. In the developed world, the el-happiest country is Taiwan, only 40% underground in our database, and it’s on the expensive side, its average cost at 40% underground still amounting to $240 million/km, and its three all-underground lines averaging $375 million/km.

It makes sense when you think about it. If construction costs in a country are higher, then it will look for ways to cut costs by building less visually desirable els (typically in developing countries) or slower light rail lines (as in the United States). If we included at-grade light rail lines, then our table would also have a wealth of high-cost American lines; as it is, we’re likely to add some at-grade heavy rail lines like the Silver Line in Washington and, if it actually begins construction, the planned PATH extension to Newark Airport.

Country-internal averages

So instead of averaging in the entire database, let’s look internally to countries, chosen to be big enough to have a mix of projects with different underground proportions. I’m also going to ignore some cases where I worry about comparability – for example, in France, above-ground lines are represented mostly by a metro extension in Toulouse and by the most outlying parts of Grand Paris Express, and I worry about comparing those with Parisian and inner-suburban tunnels. The worst exclusion has to be that of China: while there is a wealth of data there, China built more els 15-20 years ago than it does now, so comparing subways to els in (say) Shanghai is to some extent a comparison of costs in the 2010s to costs in the late 1990s and early 2000s. In that, China is hardly different from the United States – New York built many els from the 19th century until the mid-1920s, but subsequently built an almost 100% underground system.

Japan

In Japan, we go back to the 1990s, so using dollar amounts does have inflation artifacts. Thankfully, the yen has had no inflation, so we can just plug in raw yen numbers and convert at the 2020 rate of 100:1. The 100% underground lines in Japan have averaged $382 million per km, the elevated ones $123 million/km; the ratio is 3.1. The regression estimate, again using ¥100 = $1 throughout, is cost = 149.8978 + 255.9496*tunnel-proportion; the ratio using this method is 2.7.

India

India has a single 100% underground line in the database, Line 3 in Mumbai, built for $449 million/km. The pure els in India cost $158 million/km, for a subway : el ratio of 2.8. Looking only at els in Mumbai, the average inches up to $167 million/km, a ratio of 2.7. Inflation adjustment would have marginal impact as all of these lines are recent, the earliest priced in 2011 terms. The regression estimate (for all of India, not just Mumbai) is cost = 151.6146 + 222.2716*tunnel-proportion, which yields a ratio of 2.5.

Taiwan

As mentioned above, Taiwan’s three pure subways average $375 million/km. But as a note of caution, they are all regional rail tunnels, and we know from evidence in countries that build 100% underground metros and regional rail tunnels (Finland, Sweden, France, Britain, Germany…) that the latter are more expensive.

With that caveat, the four pure above-ground lines in Taiwan average $170 million/km, a ratio of 2.2. The regression estimate is cost = 183.3252 + 163.0895*tunnel-proportion, a ratio of 1.9. This is a lower ratio than in India and Japan, despite the caveat; the reason could be that the underground lines in the dataset are in Kaohsiung, Taoyuan, and Tainan, whereas the lines in Taipei and New Taipei are elevated, as the database so far does not include the older Taipei MRT lines with their city-center tunnels.

Thailand

There are no pure subways in Thailand; even the underground MRT’s extension is only 20% underground. However, the under-construction Orange Line is 75% underground, and costs $531 million/km. Overall, the regression estimate is 155.9491 + 350.2821*tunnel-proportion, which includes a number of lines in Bangkok and a cheaper half-underground line in Chiang Mai. This is a ratio of 3.2; excluding the one Chiang Mai line, this rises to 3.9.

Conclusion

Our database is consistent with the observation in the literature that the subway : el cost ratio is about 2-2.5. But a crude averaging of global costs would lead to an underestimate, since higher-cost countries are more likely to be building els. This is partly coincidence – former colonies in the developing world tend to have high costs and also wide throughfares where els are more politically acceptable – and partly the use of els to reduce costs where the country’s ability to afford subways is limited.

This reinforces the need to look at other treatments for reducing costs more carefully. It’s plausible that some policy treatments are not found in low-cost countries because those treatments are undesirable for some reason but do reduce costs. Thus, it is critical to look at both the best industry practices and the variation in practices within the parts of the world one considers best.

More on Suburban Circles

In the last post, I criticized the idea of large-radius suburban circle, using the example of the Berlin Outer Ring, at radius 10-26 km from city center. In comments, Andrew in Ezo brought up a very good point, namely that Tokyo has a ring at that radius in the Musashino Line, and ridership there is healthy enough to fill a train every 10 minutes off-peak. Of course, the Musashino Line’s intersections with the main JR East lines, like Nishi-Kokubunji and Minami-Urawa, have the ridership of a city center station in Germany rather than that of a station 25 km out. So to discuss this further, let’s drop midsize cities like Berlin and look at an actually large city: New York. Consider the following possible circle in New York, at radius 20-25 km:

See full-size version here (warning: 55 MB).

Most of the radial extensions I’ve already discussed in previous posts – for example, here. Here these extensions go somewhat further in order to meet the ring, including at Newark Airport, on Staten Island, in Bay Ridge, at Floyd Bennett Park, in Canarsie, at Starrett City, near the Queens/Nassau County line, and in Yonkers.

The ring is 151 km, of which around 87 km would be above ground, mostly replacing highways like the Belt Parkway to reduce costs. Of note, this cannot be done adjacent to an extant highway – the fast car traffic deters nearby development, making transit-oriented development impossible. So key road links around the region have to go, which is fine, since people should be transitioning from driving to taking trains. With some additional elevated construction including through City Island, across the Long Island Sound, and in low-density parts of North Jersey where demolishing houses even at $1 million per unit is cheaper than tunneling, construction costs could be reduced further. But it’s still a $20-25 billion project at average world costs, maybe $15 billion at Nordic or Korean or Southern European or Turkish costs.

The only way to pay off the costs of such a line, not to mention to fill enough trains to support frequency that can take untimed transfers (at worst a train every 10 minutes), is to have very high ridership, on the order of 400,000-500,000 per day. This is for a line that misses Manhattan and all of the big secondary job centers, like Downtown Brooklyn and Long Island City. Is this plausible?

The answer is not an obvious no. Sufficiently aggressive TOD could plausibly create ridership. But it’s still questionable. There are really a few different forces pulling such a line in different directions:

  • Using existing rights-of-way to reduce costs, hence the use of the Belt Parkway and not the denser development around Avenue U or even Flatlands.
  • Serving secondary nodes like JFK, Coney Island, EWR, and Yonkers. Potentially it would be plausible to veer inward in New Jersey in order to hit Downtown Newark, at the cost of a few extra kilometers of tunnel, making the line radial from Newark’s perspective, whereas the line as depicted above is circumferential from Newark’s perspective since it goes around city center.
  • The need to connect to radial subway and commuter rail lines, which means serving stations, opening plausible infill stations, and extending some lines toward the ring.

There are different ways to resolve this tension; the line I depicted is not the only one. For example, a higher-cost, higher-ridership version could veer inward in the Bronx and Queens, aiming to connect to Flushing and Jamaica and then replace the AirTrain JFK, leading to a ring of radius closer to 16 km than to 20-25.

I only bring this up to point out how many things have to work if you want such a ring to work out. Keeping costs to even semi-reasonable levels requires demolishing highways and engaging in aggressive TOD, which is only possible in an environment of total political victory over NIMBY and pro-car interests (note: these two are not the same!).

This is not the history of the Musashino Line. The Musashino Line originates in a freight bypass around the built-up area of Tokyo, which eventually turned into a circumferential passenger line. This is why it connects to the radial lines near but not at the busiest regional stations – at Nishi-Kokubunji and not Kokubunji, at Minami-Urawa and not Urawa, at Shin-Matsudo and not Matsudo or Kashiwa.

But even when the line is new, there are always compromises on right-of-way. Uncompromised right-of-ways are 100% possible, but not at 25 km radius, because the cost is too high to always go to the most important secondary centers. They happen when the radius is smaller, like Paris’s 8-10 km for M15, because then ridership can be high enough (M15 projects nearly a million riders a day). Farther away, ridership drops and costs rise because the line gets longer faster than per-km costs drop, so compromises are inevitable.

I am not proposing the ring above as a definitive crayon. I’m just mentioning it as something that highlights the difficulties of circumferential public transportation in the suburbs. Even as it is, the strongest segment of the ring is most likely the one in the city taking over the Belt Parkway, which could replace busy buses like the B15, B1, B3, B6, and B82. The suburban segments are weaker – there isn’t that much commuting across the Hudson that far north, and building up such commuting requires heavy commercial TOD in Yonkers, Mount Vernon, and New Rochelle.

The Limit of Circles in the Suburbs

In dense urban cores, it’s valuable to run circular rail lines. They connect dense near-center neighborhoods to one another without going through the more congested center, and help make transferring between parallel lines more efficient, again through avoiding central business district congestion. Some of the largest cities in the world even support multiple circles, line Lines 2 and 10 in Beijing, or the various overlapping circles of Moscow, Tokyo, and soon Paris. However, this system of radial lines through the center and circular lines around the center cannot go on forever. There is a limit to how far out one can build circles, which is much sharper than the limit of how far radial lines can go. Lower-density suburbs can have radial lines connecting them to city center or to near-center nodes of activity, but circumferential lines are likely to be weak.

For a concrete example, take Berlin. It has the Ring through fairly dense neighborhoods, supporting 5-minute frequency on the S-Bahn during most of the day. But it also has the Outer Ring, built in the 1950s through East Berlin and the Brandenburg suburbs to surround West Berlin and permit the construction of the Wall; today it runs regional trains, and one segment through East Berlin runs the S75 every 10 minutes, but there is no train making the entire orbit, just trains using short segments to position themselves to a better radial entry into the center of Berlin. It looks frustrating – there is circular infrastructure, why not use it? But there’s a solid reason not to run it as a true circle.

See map below:

A schematic of service patterns can be seen here.

The line’s origin as a bypass means it doesn’t serve any of the nodes near its radius, like Potsdam (too built-up), Spandau (in West Berlin), or Märkisches Viertel (also in West Berlin). The only node it does pass through is the soon-to-close Schönefeld airport, which only became important well into the Cold War; moreover, a branch parallel to the line to the southeast serves the soon-to-open Berlin-Brandenburg Airport, with plans to run many different kinds of regional services entering Berlin from both the Stadtbahn and the North-South Main Line. So a circular service would, by itself, just connect various outlying areas like Marzahn, Hennigsdorf, and Falkensee to the airport. By itself, this doesn’t support very high frequency.

Now, what the line could do is work as a network together with radial lines, connecting to them to facilitate travel not passing through the center of Berlin. However, there is not much point in transfers unless they are either high-frequency or timed. High-frequency transfers are out – the radial lines that penetrate the Outer Circle run 2-3 trains per hour. This forces the transfers to be timed.

Timed connections on lines that intersect crosswise rather than parallel with cross-platform transfers are completely possible. The trains can’t be too long, but that’s fine, a 4-car train with stair and elevator connections could have 2-3 minute transfer windows and still exchange passengers in all directions. It’s worth establishing at sufficiently important stations where a cross-platform transfer is not possible; as a four-way transfer, it’s not even that much more involved than a cross-platform transfer with timed wrong-direction transfers like Wittenbergplatz between U2 and U1/3. However, this is for one station.

All of this goes out the window when a circle intersects 12 different radial lines. Such a scheme can only work if all of the transfers are timed, or at least a large majority of them. Otherwise, people might as well take the train through the center and connect at Berlin Hauptbahnhof, or even stay on the same train if it runs through like RE 1 or RE 3.

In theory, you can time a short succession of transfers on the same line. All it really takes is to make sure that the circular line takes a half-integer multiple of the takt interval between every pair of transfer points, allowing both-direction transfers everywhere. On a few stretches of the line, it’s even plausible, with a 20-minute takt – the line would be fast because it’s so far out and has to few stops, so 7-10 km in 8 minutes (10 minus 2 for the transfer window) is not outside the realm of possibility.

Except that some segments between transfer points are still bad, like between the two just west of Spandau, or on both sides of the crossing with S5 and RE 1 in Lichtenberg. And even if they weren’t, this runs into the problem that trains are not infinitely punctual. Having 12 knots between a circular line and radials around Berlin, or even just 10 if weak ones are dropped, means that suburban Berlin would have more knots every 20 minutes than Switzerland has today every half hour (8), and not too many fewer than Switzerland is planned to have every half hour in the 2030s. The required schedule discipline is intense, especially in a big city defined by crowded rush hour trains.

This has implications elsewhere. Paris has its Grande Ceinture, which is tempting for a regional rail ring, but the frequency at which it can support a full RER line is not high; instead, the region is breaking the line into segments, to be turned over into tram-trains, with some segments diverging from the mainline to serve nodes near but not on the line.

In general, what this means is that if you’re not connecting to a major city center, there’s only so much service you can run. If you’re within the densely built-up area, as the Ring is or as the various orbitals Paris has (M2/M6, T3) or plans (M15), then it’s fine – untimed transfers are fine when trains come every 5 minutes, and overlapping one-seat rides like Prenzlauer Berg-Neukölln and Ostkreuz-Tempelhof and so on can help fill the train as well. But once frequency drops below about a train every 10 minutes, untimed transfers no longer work, which means that services that rely on connections only work if the connections are at a handful of key points, not at 12 different radii around the city.