I recently found myself involved in a discussion about Boston regional rail that involved a proposal to do more thorough regional rail-subway integration. Normally, S-Bahn systems mix some aspects of longer-range regional rail and some aspects of urban metro systems. They provide metro-like service in the urban core – for example, Berliners use the the three trunk lines of the S-Bahn as if they were U-Bahn lines. But, unlike proper metros, they branch in the suburbs and tend to have lower frequency and lower quality of infrastructure. However, there is a limit to this integration, coming from timetabling.
The characteristics of metro-like S-Bahn
When I call some S-Bahns, or some S-Bahn trunks, “metro-like,” what I mean is how users perceive them, and not how planners do. A metro line is one that users get on without concern for the timetable. It may run on a clockface schedule, for example on a 5-minute takt in Berlin, but passengers don’t try to time themselves to get on a specific train, and if the train is 1-2 minutes behind schedule then nobody really minds. This user behavior usually comes from high frequency. However, in New York, despite extensive branching and 10-minute frequencies, I classify the subway as fully metro-like because the trains are not dispatched as a scheduled railroad and even if they were, passengers don’t ever think in terms of “my Queens-bound N train arrives at :06 every 10 minutes.”
S-Bahn lines have trunks like this, but also branches that work like regional rail. The regional rail pattern in the sense of RegionalBahn is one in which passengers definitely look at timetables and try to make them, and connecting public transit lines are planned to make timed transfers. On lines branded as RegionalBahn service comes every half hour or every hour, and usually S-Bahn tails are every 15-30 minutes (occasionally 10), but the printed schedule is paramount either way; when I rode the RER B to IHES in the last three months of 2016, I memorized the 15-minute takt and timed myself to it.
The key aspect of S-Bahns is combining these two patterns. But this leads to a key observation: they have to interline a number of different service patterns, which requires planning infrastructure and service to permit both. They can’t run on pure headway management in the core, because the branches must be scheduled. But they have to use a timetabling system that permits high core frequency nonetheless.
Finally, observe that I am not discussing the type of equipment used. A subway train that extends far into the suburbs may qualify as regional rail – the Metropolitan line in London qualifies as an example on account of its highly branched service pattern in Metro-land. In the other direction, a train built to mainline standards that runs consistent service pattern with little to no branching at a range typical of metros is not, for the purpose of this issue, regional rail – examples include the Yamanote and Keihin-Tohoku Lines in Tokyo, which run identical trains to those that run deeper into suburbia but have literally no (Yamanote) or almost no (Keihin-Tohoku) variation in service patterns.
The limit of interlining
A large degree of interlining tends to reduce timetable reliability. Trains have to make junctions at specific times. This is compounded by a number of different factors:
1. Trunk throughput
The busier the trunk is, the harder it is to keep everything consistent. If you run 15 trains per half-hour, that’s 15 opportunities for a 2-minute delay to mess the order in which trains arrive, which has implications further down. If you run 4 trains per half-hour, that’s 4 opportunities, and a 2-minute delay is easily recoverable anyway.
2. Trunk length
Longer and more complex trunks introduce their own problems. If many passengers treat trains as interchangeable and don’t care what order they arrive in, then this may not be good for timekeeping – a slight delay on a branch may lead to grossly uneven headways on the trunk, which compound on busy metro lines for similar reasons as on buses. Berlin’s Stadtbahn has 14 stations from Ostkreuz to Westkreuz counting both, and this may make the branches with their 20-minute frequencies a little too difficult to fit together – evidently, peak throughput is 18 trains per hour, hardly the cutting edge. The RER A has 7 trunk stations from Vincennes to La Défense inclusive, and around 27 peak trains per hour.
3. Branch infrastructure quality
In the limit, the branches have to have excellent infrastructure quality, to be resilient to 1-2 minute delays. Timed meets on a mostly single-trunk line, routine on 15-minute branches like some lines in suburban Zurich and Tokyo, become dicey on lines that feed very busy trunks. Tokyo does this on the Yokosuka Line, which is far from the busiest (it peaks around 20 trains per hour) and Zurich on the right bank of Lake Zurich, which feeds into an S-Bahn trunk with 4 stations inclusive from Stadelhofen to Oerlikon. The busiest S-Bahn lines tend to have all-doubled outer ends.
4. One vs. two ends
If the line is single-ended, then inbound trains can just run metro-style in city center without regard for the printed schedule, use the terminal for schedule recovery, and then go outbound on schedule. Non-through-running lines are by definition single-ended, and this includes what I believe is Tokyo’s busiest regional rail line, the Chuo Rapid Line. But even some through-running lines are de facto single-ended if demand is highly asymmetric, like the Stadtbahn, which has far more demand from the east than from the west, so that one branch even turns at Westkreuz. Double-ended lines do not have this opportunity for recovery, so it’s more important to stay on schedule, especially if the end is not just busy but also has extensive branching itself.
Eric and I recently sent in a list of criteria for case selection. We’re currently funded for 6 detailed case studies, of which one is the Green Line Extension in Boston due to funding from a different grant. My guess is that we need about 15-20 different cities to have near-perfect information about the institutional and geographic factors that influence infrastructure construction costs. Because different subway lines in the same city tend to cost the same to build, and even in the same country, our 500 lines in the database are more like 50 independent observations, and there are even identifiable clusters of countries.
These clusters are important, because ideally we should have 2 cases per cluster. With 6 cases in total, we’d like to have a case for at least one per cluster, even though it’s unlikely, depending on where we can find the most detailed information and the most people who will talk to us.
1. Very low-cost countries
The first cluster is the success cases. These really come in two flavors: one is Switzerland and the Nordic countries, and the other is everywhere else with costs lower than $150 million per km, that is Spain, Portugal, Italy, Greece, Bulgaria, Turkey, and South Korea. The difference between the two flavors is that the first one consists of very high-wage countries with populations that trust their institutions, and the second consistent of countries with wages at the bottom of the first world or top of the second with populations who don’t believe me when I tell them their infrastructure construction is cheaper than in Germany. Even then, there are some important differences – for example, contracts in Turkey are lowest-bid, using the country’s high rate of construction and multitude of firms (a contract must have a minimum of 3 bids) to discipline contractors into behaving, whereas Spain instead has technical scoring for bids and only assigns 30% weight to cost.
2. Middle-range countries
This is countries close to the global average, which is around $250 million per kilometer for underground construction. China has about the same average cost as the rest of the world, and since a slight majority of our current database is Chinese, it falls in this category. France and Germany are definitely in this category; Austria, Czechia, and Romania are also in this category but have fewer distinct metro tunnels; Japan may be in this category but it’s unclear, since the few tunnels it’s building nowadays are both more expensive and more uniquely complicated, rather like regional rail. Big parts of Latin America fall into this category too, though they bleed with the high-cost category too. There’s a good case for separating China, France, Germany, and Japan into four separate categories (Austria should probably be institutionally similar to Germany), each of which gets different things right and wrong.
3. Countries with recent cost growth
This cluster consists of places that have high costs but didn’t until recently. Canada and Singapore are both competing for worst construction costs outside the United States but were not until well into the 2000s. Australia may be in this category too – it’s unclear, since Melbourne is extremely expensive to tunnel in but Sydney isn’t. New Zealand’s regional rail costs suggest it might be too – initial electrification was cheap but the regional rail tunnel is expensive. All of these countries share the characteristic of extreme cultural cringe toward Britain and the US, adopting recent British and American ideas of privatization of the state, and it would be valuable to follow up and see if this is indeed what happened with all of their infrastructure programs.
4. Rich countries with very high costs
This cluster is dominated by the US and UK. Taiwan is there too but is much smaller and likely has completely different institutional reasons – one person told me of political corruption. Hungary and Russia might be in this category too – they have very high costs (Budapest is scratching $500 million per km), but their wages are at the first/second world boundary, rather like Bulgaria or Turkey.
5. Countries on the global periphery with very high costs
This cluster consists of the high-cost world that is too poor or peripheral to be in cluster 4. This includes ex-colonies like India, Pakistan, Indonesia, Egypt, and Vietnam, but also the never- or more-or-less-never-colonized Gulf states; these two categories, the Gulf and the rest, must form two distinct flavors, but I lump them together because both seem to have extreme levels of cultural cringe and to associate bringing in European and East Asian consultants with modernity and success. (Meanwhile, parts of Europe, at least in the less self-assured East, bring in Turkish contractors.) The higher-cost Latin American countries, like Brazil and possibly Colombia, belong here too, and may form a distinct flavor. Thailand is on the edge between this cluster and cluster 2, which may befit its liminal colonial status before and during World War 2.
Where we struggle
We’ve been sending feeler messages to people in a number of places. This is far from perfect coverage – so far none of these countries is poorer than Turkey. In general, we’ve had early success in the lower-income range in cluster 1 (Italy, Spain, Korea, Turkey) and in cluster 4. Cluster 3 seems reachable too, especially since Stephen Wickens did much of the legwork for Toronto’s cost growth; we may be able to look at Sydney as well, and Singapore and Auckland seem like it shouldn’t be too difficult to find sources, nor to get people to listen if our conclusion ends up being “your government reforms in the last 15 years are terrible and should be reversed.”
Within the rich world, so far getting sources in Germany and Scandinavia has proved the hardest. I don’t know if it’s random or if it’s the fact that in countries that believe their standards of living are higher than those of the US and UK people are less likely to be forthcoming to someone who writes them in English. I’ve seen a decent amount of written material about rail capital construction projects in Germany, though not about the one I’m most interested in, that is the U5-U55 connection here in Berlin; but the rail advocates I’ve talked to are not quite in metro construction, though I have learned a lot about public transportation issues in Germany from them.
In Scandinavia things are even harder. Costs there seem pretty consistently low. A common explanation is that the rock in both Stockholm and Helsinki is gneiss, which forms a natural arch and makes tunnel boring easy, but a short tunnel in Oslo, the Løren Line, was even cheaper in softer rock. Moreover, the planned Helsinki-Turku high-speed rail is currently budgeted at €2 billion for 94 km of which 10 are in tunnel, so maybe equivalent to 140 km of at-grade line; this is noticeably below French costs, let alone German ones.
The low-income world is an entirely different situation. My suspicion is that the same cultural cringe that makes India build turnkey Shinkansen at something like 3 times its domestic cost (correcting for tunnel length) would make India eager to talk to us – if we were covered in the first-world discourse first. People in India, Nigeria, etc. know their countries are poor and are desperate to absorb the knowledge of richer places; they don’t understand the US as well as Americans do, but they understand it better than Americans understand the third world.
The reasons I’d ideally like to have 20 case studies are that there are a lot of questions about internal differences, and that things that look like clusters from cost data may not actually be similar. There are a lot of questions that doing more cases might explain.
- South Korea and Japan share many institutional similarities, and many of those are also shared with Taiwan. How come South Korea near-ties for lowest costs in the world, Taiwan near-ties for highest costs in the non-Anglophone first world, and Japan is somewhere in the middle?
- What explains why different Eastern European countries with similar histories and institutions have such cost divergence?
- Why does Italy have low metro construction costs (more in the North than in Rome and the South, but Rome is at worst average) and high costs of high-speed rail construction?
- Why does Japan have high metro construction costs where it builds and low costs of Shinkansen tunneling?
- Turkey seems similar in costs to Southern Europe, but it does things very differently – for one, it uses lowest-bid contracting. To what extent this is about Turkey’s very high rates of construction recently, and does this generalize elsewhere? Of note, there are extremely high construction rates all over middle-cost China, and also decently high rates in high-cost India, Singapore, and California.
- The Netherlands is institutionally within the same range of what’s seen elsewhere in Northern Europe, and yet its construction costs are high. Is this just a matter of alluvial soil tunneling? If so, why did HSL Zuid cost so much?
Our current project timeline includes posting the dataset of urban rail lines and their construction costs in a month. This means looking at various spreadsheets and checking them item by item. Part of it is checking for mistakes, which do unfortunately occur for some items. Sometimes even the sources have mistakes – for example, most sources for the Sinbundang Line in Seoul say it cost 1.169 trillion won (e.g. here, a bit higher in PDF-p. 60 here, and my now-linkrotted original source), but one says 1.69 trillion, which I’m fairly certain is a typo. However, the biggest source of errors in my file is that the majority of lines I included were under construction as of 2018, so cost overruns and schedule slips remain possible. And unfortunately, while a number of projects have significantly higher costs, the US is especially rich in cost overruns.
The case of Los Angeles is the most infuriating. It is not the highest-cost American city, not even close – nothing is within a factor of 2 of dislodging Second Avenue Subway Phase 2 from its throne. However, it’s making a strong bid for the second highest. The third phase of the Purple Line extension in the Westside, connecting Century City (reached in the second phase) with UCLA and the VA Hospital in Westwood, is $3.6 billion for 4.2 km. Costs have been creeping up from what used to start with a 2, and now this is $857 million per kilometer. This is in year-of-expenditure dollars, so in 2020 money it’s more like $800 million per km.
The contrast to what LA looked like in the 2000s is huge. In 2010-11, it looked like the lowest-cost US city; it was still really expensive to tunnel in, but it seemed more like $300-400 million per km. But things keep getting worse. If Canada and Australia and Singapore and Britain today are like the US 10-15 years ago, the US is pulling ahead, eager to be #1 in everything.
Of note, this is an environment with high and stable funding levels. Transit funding in Los Angeles is bonded through 2060. Contracts in Los Angeles are let on a lowest-cost basis; sometimes there’s a technical score, but officials at LA Metro told Eric and me that unless the weight of the technical score is very high, around 70%, then in practice the contract will go to the lowest bidder. Now, it is not true that all low-cost countries have high technical score weights like Spain does; Turkey in particular uses lowest cost, and uses its high construction rates to discipline bidders into behaving, since shoddy work will risk their ability to get future contracts. Nonetheless, in Los Angeles the great extent of construction does not involve any such discipline. Metro prefers dealing with familiar contractors, even if their record is poor.
Americans, as a culture, would rather die than be more like another nation. Taiwan’s last domestic corona infection was on April 12th, the US averages 60,000 such infections a day. The sort of change required to make Americans forget about 2 generations of learned public-sector helplessness is immense, and will not come spontaneously (and no, your chosen revolutionary movement won’t do it – revolutionaries are selected for incompetence).
The upshot is that the share of current senior managers who have anything to contribute to improving public transportation in the US is very low. Not zero, but still very low. The process selects the least imaginative, least technically apt, and least curious people. Whether it’s best practices that do not look outside the Boston-Seattle-San Diego-Miami quadrilateral, or grants that have language that makes it clear foreign knowledge is unwelcome, or hiring practices that exclude immigrants on visas, everything about the process in the US screams it. It’s not a coincidence that the US has the world’s highest construction costs, and when other countries begin to catch up often thanks to adoption of American practices, the US keeps staying ahead.
I was recently asked about the issue of incrementalism in infrastructure, with specific reference to Strong Towns and its position against big projects (e.g. here). It’s useful to discuss this right now in context of calls for a big infrastructure-based federal jobs program in the United States. The fundamental question to answer is, what is the point of incremental projects?
The issue is that the legitimate reason to prefer less ambitious projects is money. If a new subway tunnel costs $5 billion, but you only have the ability to secure $1.5 billion, then you should build what you can for $1.5 billion, which may be a tram rather than a subway, or surface improvements to regional rail instead of a new regional rail tunnel, etc.
A secondary legitimate reason is that even if there is more money, sometimes you get better results out of building something less flashy. This is the electronics-before-concrete approach – in a developed country it’s almost always cheaper to invest in signaling, electrification, and platform upgrades than to build new tunnels. This can look incremental if it’s part of a broader program: for example, if there’s already investment in electrification in the region then extending wires is incremental, so that completing electrification on the commuter rail lines in New York, reopening closed suburban branches in Philadelphia with new wires, and even completing electrification in a mostly-wired country like Belgium and the Netherlands would count.
But the example of electrification in a mostly already electrified place showcases the differences between cost-effectiveness and incrementalism. The same investment – electrification – has a certain cost-effectiveness depending on how much train traffic there is. There’s a second-order effect in that the first line to be electrified incurs the extra cost of two train fleets and the last line has a negative cost in no longer needing two fleets, but this isn’t relevant to first order. Nonetheless, electrifying a system where electrification is already familiar is considered incremental, to the point that there were extensions of electrification in suburban New York in the 1980s and there remain semi-active projects to build more, whereas electrifying one that is currently entirely diesel, like Boston, is locally considered like a once-in-a-generation project.
And that is the real problem. American cities are hardly hotbeds of giant flashy construction. They barely are in highways – big highway construction plans are still done but in suburbs and not anywhere where public transit is even remotely relevant. And transit construction plans are always watered down with a lot of reconstruction and maintenance money; most of the money in the Los Angeles sales tax measures that are sold to the urbanist public as transit measures is not about rail construction, which is why with money programmed through 2060 the region is going to only have one full subway line; an extension of the Red Line on South Vermont is scheduled to open in 2067, partly because construction costs are high but mostly because there are maintenance projects ahead in line.
So in reality, there are two real reasons why incrementalism is so popular in the United States when it comes to transportation, neither of which is legitimate. Both are types of incompetence, but they focus on different aspects of it.
The first reason is incompetence through timidity. Building something new, e.g. rail electrification in Boston or in California, requires picking up new knowledge. The political appointees in charge of transit agencies and the sort of people who state legislators listen to do not care to learn new things, especially when the knowledge base for these things is outside their usual social networks. Can Massachusetts as a state electrify its rail network? Yes. Can it do so cheaply? Also yes. But can the governor’s political appointees do so? Absolutely not, they are incurious and even political people who are not beholden to the governor make excuses for why Massachusetts can’t do what Israel and Norway and New Zealand and Austria and Germany do.
In that sense, incrementalism does not mean prudence. It means doing what has been done before, because the political people are familiar with it. It may not work, but it empowers people who already have political clout rather than sidelining them in favor of politically independent technocrats from foreign countries who might be too successful.
The second reason is incompetence through lack of accountability. This is specific to an approach that a lot of American urbanists have backed, wrongly: fix-it-first, or in its more formal name state of good repair (SOGR). The urbanist emphasis on SOGR has three causes: first, in the 1980s New York had a critical maintenance backlog and neglected expansion in order to fix it, which led to positive outcomes in the 1990s and 2000s; second, in highways, fix-it-first is a good way to argue against future expansion while hiding one’s anti-car ideology behind a veneer of technical prudence; and third, Strong Towns’ specific use case is very small towns with serious issues of infrastructure maintenance costs and not enough residential or commercial demand to pay for them, which it then generalizes to places where there’s more market demand for growth.
In reality, the situation of 1980s’ New York was atypical. Subsequently, the SOGR program turned into a giant money pit, because here was an opportunity to spend enormous sums of capital construction money without ever being accountable to the public in the form of visible expansion. Ask for a new rail line and people will ask why it’s not open – California got egg on its collective face for not being able to build high-speed rail. Ask for SOGR and you’ll be able to brush away criticism by talking about hidden benefits to reliability. Many passengers may notice that trains are getting slower and less reliable but it’s easier in that case to intimidate the public with officious rhetoric that sounds moderate and reasonable.
Incrementalism is fundamentally a method of improving a legitimate institution. The EU needs incremental reform; China needs a democratic revolution. By the same token, in infrastructure, incrementalism should be pushed when, and only when, the status quo with tweaks is superior to the alternatives. (Note that this is not the same as electronics-before-concrete – what Switzerland did with its rail investment in the 1990s was very far-reaching, and had tangible benefits expressed in trip times, timed connections, and train frequency, unlike various American bus redesigns.) Strong Towns does not believe that there’s anything good about the American urban status quo, and yet it, and many urbanists, are so intimidated by things that happened in the 1950s, 60s, and early 70s that they keep pushing status quo and wondering why there is no public transportation outside about eight cities.
I was asked a few months ago about priorities for street pedestrianization in New York. This issue grew in importance during the peak of the corona lockdown, when New Yorkers believed the incorrect theory of subway contagion and asked for more bike and pedestrian support on the street. But it’s now flared again as Mayor de Blasio announced the cancellation of Summer Streets, a program that cordons off a few streets, such a the roads around Grand Central, for pedestrian and bike traffic. Even though the routes are outdoors, the city is canceling them, citing the virus as the reason even though there is very little outdoor infection.
But more broadly, the question of pedestrianization is not about Summer Streets, which is an annual event that happens once and then for the rest of the year the streets revert to car usage. It’s about something bigger, like the permanent Times Square and Herald Square pedestrianization.
In general, pedestrianization of city centers is a good thing. This can be done light, as when cities take lanes off of roadways to expand bike lanes and sidewalks, or heavy, as when an entire street loses car access and becomes exclusive to pedestrians and bikes. The light approach should ideally be done everywhere, to reduce car traffic and make it viable to bike; cycling in New York is more dangerous than in Paris and Berlin (let alone Amsterdam and Copenhagen) since there are too few separated bike lanes and they are not contiguous and since there is heavy car traffic.
The heavy approach should be used when feasible, but short of banning cars cannot be done everywhere. The main obstacle is that in some places a critical mass of consumers access retail by car, so that pedestrianization means drivers will go elsewhere and the region will suffer; this happened with 1970s-era efforts in smaller American cities like Buffalo, and led to skepticism about the Bloomberg-era Times Square pedestrianization until it was completed and showcased success. Of course, Midtown Manhattan is rich in people who access retail by non-auto modes, but it’s not the only such place.
Another potential problem is delivery access. This is in flux, because drone delivery and automation stand to simplify local deliveries, using sidewalk robots at pedestrian scale. If delivery is automated then large trucks no longer offer much benefit (they’re not any faster than a bicycle in a congested city). But under current technology, some delivery access is needed. In cities with alleys the main street can be pedestrianized with bollards while the alleys can be preserved for vehicular access, but New York has about three alleys, which are used in film production more than anything because they connote urban grit.
Taking all of this together, the best places for pedestrianization are,
- City centers and near-center areas. In New York, this is the entirety of Manhattan south of Central Park plus Downtown Brooklyn and Long Island City. There, the car mode share is so low that there is no risk of mass abandonment of destinations that are too hard to reach by car.
- Non-residential areas. The reason is that it’s easier to permit truck deliveries at night if there are no neighbors who would object to the noise.
- Narrow streets with plenty of commerce. They’re not very useful for drivers anyway, because they get congested easily. If there are deliveries, they can be done in off-hours. Of note, traffic calming on wider streets is still useful for reducing pollution and other ills of mass automobile use, but it’s usually better to use light rather than heavy traffic reduction, that is road diets rather than full pedestrianization.
- Streets with easy alternatives for cars, for example if the street spacing is dense. In Manhattan, this means it’s better to pedestrianize streets than avenues.
- Streets that are not useful for buses. Pedestrianized city center streets in Europe are almost never transit malls, and the ones I’m familiar with have trams and not buses, e.g. in Nice.
Taking this all together, some useful examples of where to pedestrianize in New York would be,
- Most of Lower Manhattan. There are no residents, there is heavy commerce, there is very heavy foot traffic at rush hour, and there are enough alternatives that 24/7 pedestrianization is plausible on many streets and nighttime deliveries are on the rest.
- Some of the side streets of Downtown Brooklyn and Long Island City. This is dicier than Manhattan – the mode share in those areas as job centers is far below Manhattan’s. A mid-2000s report I can no longer find claimed 50% for Downtown Brooklyn and 30% for LIC, but I suspect both numbers are up, especially LIC’s; Manhattan’s is 67%, with only 15% car. So there’s some risk, and it’s important to pick streets with easy alternatives. Fulton Mall seems like a success, so presumably expansions can start there and look at good connections.
- St. Mark’s. It’s useless for any through-driving; there’s a bus but its ridership is 1,616 per weekday as of 2018, i.e. a rounding error and a prime candidate for elimination in a bus redesign. There’s so much commerce most buildings have two floors of retail, and the sidewalk gets crowded.
- Certain Midtown side streets with a lot of commerce (that’s most of them) and no buses or buses with trivial ridership (also most of them). One-way streets that have subway stations, like 50th and 53rd, are especially attractive for pedestrianization. Two-way streets, again, are valuable targets for road diets or even transit malls (though probably not in Midtown – the only east-west Manhattan-south-of-59th-Street bus route that screams “turn me into a transit mall” is 14th Street).
The construction costs of rail infrastructure in the Arab world are globally atypical. We looked at the entire region, because of the common use of the literary Arab language; nearly all of this work is due to a New School student named Anan Maalouf, who’s doing long-term work on urban planning as relevant to Nazareth. Here is a presentation he gave at NYU on the subject last month. Update 7/22: here is an updated version of the presentation.
There are identifiable clusters in the Arab world, which is not surprising – it’s similar to how there is a common Nordic cost (which is low), a common cost to the English-speaking world (which is high), and so on. Of course, these clusters are not perfectly predictable ex ante; in light of the most important global pattern with the coronavirus crisis, I keep stressing that there is no distinct Europe vs. East Asia cluster when it comes to costs, and instead both regions have similar averages and huge internal variations. The Arab world does not form an entire cluster itself, but its clusters are at least somewhat understandable based on internal divisions.
One cluster is the six states of the Gulf Cooperation Council: Kuwait, Saudi Arabia, Qatar, Bahrain, the UAE, and Oman. All are distinguished by high incomes, comparable to those of the developed world, but coming almost exclusively from oil extraction. All also have atypically large numbers of immigrants, who form large majorities of the populations of the UAE and Qatar, and who have few rights and earn very low wages by local standards. One might expect that in such an environment, construction costs should be low, since there is ample cheap labor but also money for imported capital. Instead, these states all have high costs; for example, the Doha metro project costs around $700 million per kilometer, and is not even 100% underground but only 90%.
The explanation, per Anan and an Israeli-British planner named Omer Raz, is that there is no interest in cost control in the Gulf region. The GCC states have money. They are buying prestige and the trappings of modernity; for all of their crowing about the superiority of their traditional values and Islamic law, they crave Western acceptance, in similar vein to Singapore. So they invite first-world consultancies to build their infrastructure to build what Aaron Renn would call “world-class in Doha” (or Dubai, or Riyadh, etc.), as opposed to “world-class Doha,” i.e. domestic production that is good enough that other people are attracted to it. On top of it all, Omer gave an example in which Saudi Arabia was not a reliable partner for these foreign consultancies; Anan, too, notes a plethora of postponements and cancellations of rail lines, sometimes because of changing economic conditions, sometimes because these lines are international and relationships between Saudi Arabia and Qatar deteriorated recently, etc.
Another cluster consists of Egypt and Iraq. Both have high costs, in line with other third-world ex-colonies, like India, Vietnam, Indonesia, and Nigeria. The Cairo Metro extensions are $600-700 million per km; the Baghdad Metro is, in PPP terms, $330 million per km for an all-elevated project. This is not surprising – these countries use first-world consultancies with background in high-wage, strong-currency, cheap-capital economies. Unlike in the other datasets, like mine or Yinan Yao’s, Anan included a crucial piece of information: who the lead contractor or consultant was. It’s often a foreign firm, from a much richer country – in Iraq’s case, it’s Alstom. On the other hand, Egypt is using a domestic contractor, Orascom, and costs there remain high.
Finally and most interestingly, there is the Maghreb. One would expect that Tunisia, Algeria, and Morocco should have high costs, just like the other ex-colonies. However, they do not. Anan pointed out that the Arab world inverts my theory about how ex-colonies have higher costs than never-colonized countries like Iran, Turkey, and China. He adds that these countries have much closer ties with France than other ex-colonies do, whether they used to be French outside Africa (i.e. Vietnam) or other European empires’ (e.g. India, Indonesia, Nigeria). Alstom has had continuous presence in the area for 20 years.
In a sense, France didn’t fully decolonize in the Maghreb and the Sahel. It still views these regions as its near abroad, with a forever war in Mali, currency pegs, and deep economic ties with the higher-functioning countries. One can even see the French way of building urban rail in the Maghreb, for example on the Sfax tramway. This isn’t quite every urban subway – the Algiers Metro is pretty expensive. But the Oran Metro has normal costs, and light rail systems like those of Sfax and Casablanca have reasonable costs, as does the TGV system running as Morocco’s high-speed rail system.
So perhaps the issue is that the French planners in the Maghreb are there for long enough that they know the local conditions, and build in accordance with them. In contrast, systems have higher costs if they try to imitate first-world methods either due to first-world consultants’ unfamiliarity with the local situation or due to local cultural cringe.
Normally, the best interstation distance between subway or bus stops does not depend on population density. To resurrect past models, higher overall density means that there are more people near a potential transit stop, but also that there are more people on the train going through it, so overall it doesn’t influence the decision of whether the stop should be included or deleted. Relative density matters, i.e. there should be more stops in areas that along a line have higher density, for example city centers with high commercial density, but absolute density does not. However, there is one exception to the rule that absolute density does not matter, coming from line spacing and transfer placement. This can potentially help explain why Paris has such tight stop spacing on the Métro and why New York has such tight stop spacing on the local subway lines.
Stop spacing and line spacing
The spacing between transit stops interacts with that between transit lines. The reason is that public transportation works as a combined network, which requires every intersection between two lines to have a transfer. This isn’t always achieved in practice, though Paris has just one missed connection on the Métro (not the RER), M5/M14 near Bastille; New York has dozens, possibly as many as all other cities combined, but the lines built before 1930 only have one or two, the 3/L in East New York and maybe the 1/4-5 around South Ferry.
The upshot is that the optimal stop spacing depends on the line spacing. If the line spacing is tight – say this is Midtown Manhattan and there is a subway line underneath Lex/Park, Broadway, 6th, 7th, and 8th – then crossing lines have to have tight stop spacing in order to connect to all of these parallel lines. In the other direction, there were important streetcars on so many important cross-streets that it was desirable to intersect most or ideally all of them with transfers. With so many streetcar lines extending well past Midtown, it is not too surprising that there had to be frequent subway stops.
So why would denser cities have tighter line spacing?
Line spacing and density
The intuitive relationship between line spacing and density is that denser cities need more capacity, which requires them to build more rail lines.
To see this a bit more formally, think of an idealized city on a grid. Let’s say blocks are 100*100 meters, and the planners can figure out the target density in advance when designing the subway network. If the city is very compact, then the subway could even be a grid, at least locally. But now if we expect a low-density city, say 16 houses per block, then the subway grid spacing should be wide, since there isn’t going to be much traffic justifying many lines. As the city densifies, more subway is justifiable: go up to missing middle, which is around 30-40 apartments per block; then to the Old North of Tel Aviv, which would be around 80; then to a mid-rise euroblock, which is maybe 30-40 per floor and 150-200 per block; then finally a high-rise with maybe 500-1,000 apartments.
Each time we go up the density scale, we justify more subway. This isn’t linear – an area that fills 500 apartments per block, which is maybe 100,000 people per km^2, does not get 20 times the investment of an area on the dense side of single-family with 16 houses per block and 5,000 people per km^2. Higher density justifies intensification of service, with bigger and more frequent trains, as well as more crowding. With more subway lines, there are more opportunities for lines to intersect, leading to more frequent stop spacing.
Even if the first subway lines are not planned with big systems in mind, which New York’s wasn’t, the idea of connections to streetcar lines was historically important. A stop every 10 blocks, or 800 meters, was not considered on the local lines in New York early on; however, stops could be every 5 blocks or every 7, depending on the spacing of the major crosstown streets.
Dense blobs and linear density
Line spacing is important to stop spacing not on parallel lines, but crossing lines. If a bunch of lines go north-south close to one another, this by itself says little about the optimal spacing on north-south lines, but enforces tight spacing on east-west lines.
This means that high density encourages tight stop spacing when it is continuous in a two-dimensional area and not just a line. If large tracts of the city are very dense, then this provides justification for building a grid of subway, since the crosstown direction is likely to fill as well; in New York, 125th Street is a good candidate for continuing Second Avenue Subway Phase 2 as a crosstown line for this reason.
In contrast, if dense development follows a linear corridor, then there isn’t much justification for intense crosstown service. If there’s just one radial line, then the issue of line spacing is moot. Even if there are two closely parallel radial lines in the same area, a relatively linear development pattern means there’s no need for crosstown subways, since the two lines are within walking distance of each other. The radial urban and suburban rail networks of Tokyo and Seoul do not have narrow interstations, nor do they have much crosstown suburb-to-suburb service: density is high but follows linear corridors along rapid transit. Dense development in a finger plan does not justify much crosstown service, because there are big low-density gaps, and suburb-to-suburb traffic is usually served efficiently by trips on radial lines with a transfer in city center.
The Modernizing Rail (Un)Conference happened last Sunday. We’re still gathering all the materials, but here are video uploads, including the keynote by Michael Schabas.
We will also have slides as given by presenters who used them. But for now, here are the slides used by the keynote. You may notice that the recording does not begin on the first slide; we missed Schabas’s introduction and some remarks on his background, detailing his 40 years of experience designing public transit systems in a number of countries, mainly Britain and Canada but also elsewhere in the developed world.
My session on construction costs was slide-free (and was not recorded), since I mostly just showed people around our under-construction cost dataset and answered a lot of questions. Some of those questions were annoying, by which I mean they questioned my thinking or brought up a point I haven’t considered before. I am not talking too much about it partly because I was mostly (mostly) repeating things I’ve said here, and the full database should be out later this summer, with all the mistakes I’ve made in currency conversion rates and in not updating for cost overruns fixed.
After my breakout, I was uncertain between which of two sessions to attend – one on HSR-legacy rail compatibility by María Álvarez, and one on equity issues in rail planning, by Grecia White and Ben She. I ended up going to the latter, which featured interesting discussions of inclusion of low-income people and minorities, both as riders (that is, serving people who are not middle-class whites better on regional rail) and as workers (that is, diversifying planning and engineering departments).
It went well in that there was no monopolization of discussion by people who have more a comment than a question, or any open racism or sexism; but it was somewhat frustrating in that while there was a lot of productive discussion of racial equality in rail planning, there was very little of gender equality even though we did intend to talk about both; Grecia was specifically interested in discussing these, for example women’s perceptions of public safety. This is in line with conference demographics – the organizing team and the breakout presenters were each one-third people of color, in line with US demographics; but the organizing team had 2/18 active women and the presenters 3/15. TransitMatters is similar in that regard – racial diversity is comparable to that of the Boston region, and the proportion of regulars who are queer is enormous, but there are very few women.
Finally, I hosted a session on how to set up a transport association, a.k.a. Verkehrsverbund. Christof Spieler did the most talking, and German attendees explained a lot about the difference between a transport association and agency amalgamation. But for the most part that session felt like an ersatz conclusion to the entire conference; it technically lasted an hour, but once the hour had lapsed, people from other sessions came to the room and the conversation continued naturally, talking a bit about different transit planning issues in Germany and a bit about applicability to rail reform in the Northeastern US.
The Deutschlandtakt plans are out now. They cover investment through 2040, but even beforehand, there’s a plan for something like a national integrated timetable by 2030, with trains connecting the major cities every 30 minutes rather than hourly. But there are still oddities that are worth discussing, especially in the context of what Germans think trains are capable of and what is achieved elsewhere.
The key is the new investment plans. The longer-term plans aren’t too different from what I’ve called for. But somehow the speeds are lower. Specifically, Hamburg-Hanover is planned to be a combination of legacy rail (“ABS”) and newly-built high-speed rail (“NBS”), dubbed the Alpha-E project, with trains connecting the two cities in 63 minutes.
The point of an integrated takt timetable is that trains should connect major nodes (“knots”) in just less than an integer number of half-hours for hourly service, or quarter-hours for half-hourly service. Trains connect Zurich and Basel in 53 minutes and each of these two cities with Bern in 56 minutes, so that passengers can change trains on the hour and have short connections to onward destinations like Biel, St. Gallen, and Lausanne. To that effect, Switzerland spent a lot of money on tunnels toward Bern, to cut the trip time from somewhat more than an hour to just less than an hour. So the benefits of cutting trip times from 63 minutes to just less than an hour are considerable.
What’s more, it is not hard to do Hamburg-Hanover in less than an hour. Right now the railway is 181 km long, but the planned Alpha-E route is shorter – an alignment via the A 7 Autobahn would be around 145 km long. The Tokaido Shinkansen’s Hikari and Nozomi trains run nonstop between Nagoya and Kyoto, a distance of 134 km, in 34 minutes. Kodama trains make two additional stops, with long dwell times as there are timed overtakes there, and take 51 minutes. Shinkansen trains have better performance characteristics than ICE trains, but the difference in the 270-300 km/h range is around 25 seconds per stop, and the Tokaido Shinkansen is limited to 270 km/h whereas an Alpha-E NBS would do 300. So doing Hamburg-Hanover in less than 40 minutes is eminently possible.
Of course, major cities have slow approaches sometime… but Hamburg is not a bigger city than Kyoto or Nagoya. It’s about comparable in size to Kyoto, both city proper and metro area, and much smaller than Nagoya. Hanover is a lot smaller, comparable to cities served by Hikari but not Nozomi, like Shizuoka and Hamamatsu. Hamburg-Hanover has 12 km between Hamburg and Harburg where trains would be restricted to 140 km/h, and around 6 in Hanover where trains would be restricted to 130 km/h; in between they’d go full speed, which at the performance characteristics of the next-generation Velaro would be a little more than 35 minutes without schedule padding and maybe 38 minutes with. This fits well into a 45-minute slot in the takt, permitting both Hanover and Hamburg to act as knots.
Moreover, if for some reason a full NBS is not desirable – for example, if NIMBY lawsuits keep delaying the project – then it’s possible to built a partial NBS to fit into an hourly time slot, trains taking around 53 minutes. The cost per minute saved in this context is fairly consistent, as this is a flat area and the legacy line is of similar quality throughout the route; if for some reason the cost per minute saved is too high, e.g. if nuisance lawsuits raise construction costs above what they should be on such a route, which is around 15-20 million euros per kilometer, then going down only to 53 minutes is fine as it makes the hourly takt work well.
And yet, it’s not done. The biggest cities are not planned to have regular half-hourly knots, because there’s too much traffic there. But Hanover is in fact a perfect place for a knot, with trains going east to Berlin, west to the Rhine-Ruhr, north to Hamburg, and south to Frankfurt and the cities of Bavaria. Hamburg is at the northern margin of the country, with trains going mostly south to Hanover, but having some timed connection with trains continuing north to Kiel and eventually Copenhagen is not a bad idea.
For some reason, German rail activists, including presumably the ones who pushed the Deutschlandtakt from the bottom up while the ministry of transport was run by pro-car conservatives, are just too conservative about the capabilities of trains. I’ve seen one of the D-Takt groups, I forget which one, criticize plans to build an NBS between Hanover and Bielefeld, a segment on which the existing line is fairly slow, on the grounds that it could never fit into a knot system. It is not possible to do the roughly 100 km between Hanover and Bielefeld (actually closer to 95 km) in less than half an hour to fit a knot, they say – average speeds higher than 200 km/h are only found on very long nonstop stretches of high-speed rail, as in France, they insist. Shinkansen trains achieve such speeds over such segments every day, and even with the slightly lower performance characteristics of the next-generation Velaro, Hanover-Bielefeld in 24 technical minutes and 26 minutes with 7% pad (and the Shinkansen only has 4% pad) is feasible.
I genuinely don’t know why there is such conservatism among German rail planners and advocates. It could be that Europeans don’t like learning from Asia, just as Americans don’t like learning from Europe. There are examples of faster trains than in Germany within Europe, but maybe German advocates discount French and Spanish examples because of genuine problems with French and Spanish rail operations, leading them to also make excuses like “the trains run nonstop for 500 km and that’s why they’re fast” to avoid adopting the things where France and Spain are genuinely superior to Germany.
Nothing about the integrated timed transfer schedule idea impedes high speeds. On the contrary, in some cases, like Hanover-Hamburg but also the planned Frankfurt-Stuttgart line (already in place south of Mannheim), high speeds are necessary to make the desired knots. Moreover, where distances between cities are long compared with desired frequency, as on Berlin-Hanover, it’s possible to build 300 km/h lines and cut entire half hours or even full hours from trip times. Germany could innovate in this and build such a network for an amount of money well within the limits of the corona recovery package, which includes €50 billion for climate mitigation.
But either way, Germany is about to make mistakes of underinvestment because it’s not quite willing to see where the frontier of rail transport technology is. This is not the American amateur hour, it’s not the sort of situation where I can spend a few hours with maps and come up with better timetables myself, but even so, the plans here are far too timid for Germany’s medium- and long-term transportation needs.
The D-Takt is a step forward, don’t get me wrong. None of the investments I’m seeing is bad. But it’s a small, hesitant step forward rather than a firm, bold walk toward direction of intercity rail modernization. A country that expects intercity rail ridership to double, putting Germany’s per capita intercity rail ridership in the vicinity of Japan’s, should have something similar to the Shinkansen network, with a connected network of NBS links between the major cities averaging 200-250 km/h and not 120-160 km/h.
It’s been a while since I last wrote this series, where I covered the American, Soviet, and British traditions of building urban rail. I’d like to return by focusing attention on the French tradition, which has been influential not just within France itself but also to some extent former French colonies, especially Quebec.
An issue I hope to return to soon is the extent to which France has not truly decolonized; former French colonies in Africa, especially the Maghreb, rely on French technical expertise for construction, and often outsource their monetary policy (as with the CFA franc, but Morocco too has a peg to a dollar and euro mix). This matters, because this means the French way of building urban transit is influential in former French colonies in Africa, whereas the British tradition’s impact on India, Nigeria, and so on is limited.
The history of Paris
Like Britain, the USSR, and the US, France has a dominant financial center that its smaller cities aim to imitate. This imitation has been much more extensive than in the US and UK – to the extent that secondary French cities diverge in design principles from the capital, they do things that were fashionable in Paris at the time they built out their rail networks rather than things that were fashionable in Paris when Paris built the Métro. Thus, it is especially valuable to look at the history of urban rail in Paris.
The Paris Métro opened in 1900, as the world’s fifth metro system. Already then, it had a critical feature that the previous four (London, Budapest, Chicago, Glasgow) lacked: it was a centrally planned multi-line system. The city planned a coordinated system of what would become Lines 1-6, in the shape of a # in a circle: Lines 1 and 3 would run east-west, Lines 4 and 5 would run north-south, and Line 2, eventually split into Lines 2 and 6, would run the trace of the wall that delineated the city’s pre-1860 boundary.
The Métro was a municipal effort run by the municipal CMP, designed around the city’s needs, which included not just good transportation but also separation from the working-class suburbs. Whereas the London Underground was mostly technologically compatible with the mainline system, the Métro was deliberately designed not to be, to protect the urban middle class from transport integration with the suburban poor. This led to the following features:
- The trains are extremely narrow, 2.4-2.44 meters wide, compared with about 2.9 m on the mainline; the deep Tube trains in London, held to have the narrowest loading gauge on a standard-gauge railway, are 2.68 m wide.
- The interstation distance is very short, 562 meters on average. Paris is compact and dense and the short interstations are only a real problem in the suburbs.
- The trains run on the right, like French road traffic, whereas French trains run on the left.
- No legacy lines were incorporated into the system, unlike in New York and London, and thus the shape of the network looks much more like how one would design a metro network from scratch and less like how old West London branches or Brooklyn excursion lines looked.
Like New York and Berlin and unlike London, Paris built the Métro cut-and-cover. The lines built before the 1990s all closely follow streets except when they cross the river – and in the 1900s the Line 4 river crossing was the hardest part of the system to build, opening in 1908 whereas the rest of the network had opened by 1906. This was done entirely by hand, forcing the lines to curve where the streets did, which led to two notable warts. First, while most of the system had a design standard of 60 meter curve radii, Line 1 goes down to 40 at Bastille. And second, Line 5, which crosses the Seine on a bridge, cannot serve Gare de Lyon; the engineers could not get it to curve that way while still running through to Gare d’Austerlitz and the Left Bank, so instead the transfer point between Lines 1 and 5 is Bastille, and more recently the RER A and Line 14 both cross Line 5 without a transfer as they run express from Gare de Lyon to Châtelet.
That said, the missed connection between Lines 5 and 14 is the only one in the system, though two more are under construction on Line 14 extensions. Only one among the major metro systems of the world runs entirely without missed connections, the Mexico City Metro, which has unusually low line density in the core and unusually many tangential lines.
The suburbs and the RER
The Métro’s deliberate exclusion of the suburbs made sense from the point of view of a middle-class Parisian in 1900 who was mortally afraid of the working class. But by the 1930s, it was leading to serious design constraints. Further Métro extensions both densified the network and extended it outward, and in the 1930s, lines began to extend past city limits, to such suburbs as Lilas, Issy, Neuilly, and Montreuil. The short interstations made longer extensions infeasible, and some solution involving regional rail was needed.
In 1938, CMP bought and electrified the Ligne de Sceaux, which alone among the Paris commuter lines had reached close to city center, terminating at Jardin du Luxembourg rather than at the farther away rail stations, which are located at or just inside the M2/M6 ring. Then after the war, as suburbanization intensified and commuter traffic at Gare Saint-Lazare grew increasingly congested, CMP’s successor RATP collaborated with SNCF on connecting regional rail branches to form an express system, that is the RER; the Ligne de Sceaux became the southern half of the RER B, while a similar branch going east paired with one of the Saint-Lazare lines to form the RER A. Through-service opened in 1977, roughly at the same time as the German S-Bahn through-tunnels, but the system grew much larger as Paris was and remains far larger than any German city.
But it is not exactly correct to view the RER as identical to a German S-Bahn, or to one of the RER’s inspirations, the Tokyo through-running system. A number of features characterize it, some shared with other urban regional rail systems, some not:
- There are multiple trunk lines through the city, which form something like a coherent network among themselves, and do not share rolling stock. The biggest warts are that the RER B and D share tracks (but no platforms) on one interstation, and that the RER C mostly stays on the Left Bank, legacy of when planning in Paris conceived of the area around Saint-Michel as a central area to be served, where in reality it is decidedly secondary to the CBD stretching from Les Halles to Champs-Elysées.
- It runs largely, though not entirely, on separate tracks from non-RER lines.
- It is locally viewed as deficient to Métro service – researchers who use the RER B to get to IHES think of it as lower-quality, lower-class service than the Métro in the city and its immediate suburbs. I suspect that this is why Grand Paris Express is designed around Métro standards rather than as intensification of RER service, while RER expansion has fallen to the wayside.
- RER-Métro integration is imperfect: the fares are integrated but there are still barriers between RER and Métro platforms, and there are many missed RER-Métro connections, whereas in Berlin the S-Bahn and U-Bahn have only one missed connection between them.
- The interstation is around 2-3 km, but it’s actually slightly longer on the new urban tunnels build for the RER A, B, D, and E than on the legacy lines in the inner suburbs; this feature also exists in a much more extreme form in the United States, but in Berlin and Tokyo it is completely absent.
Exporting Parisian ideas
Parisian metro planning influenced Montreal, Mexico City, and the smaller French cities, in chronological order. We see any of the following features in those cities:
- Rubber-tired metros. This technology was in vogue in postwar Paris, which converted Lines 1, 4, and 11 to it figuring this was just better than steel wheels, and also Line 6, figuring that an elevated line would benefit from a quieter propulsion system.
- Non-radial network design. London and the systems inspired by it, including all Eastern bloc systems, have radial design, with nearly all lines entering a relatively small city center. Paris expanded its #-in-a-circle system to a combination of a radial network and a grid, with a large number of pairs of parallel lines. Mexico City, the largest system inspired by Paris, is rich in tangential lines but has only three lines serving city center, which are by far the three busiest.
- Short interstations, though this is truer domestically than in Montreal and Mexico City.
- Driverless operations. This technology became popular in the 1980s, starting with the Lille Metro, and France has used it on new lines in Paris (M14) and elsewhere (Lyon Line D, both lines in Toulouse), also innovating in converting manual lines to automatic on Paris M1 and now M4. While the Parisian lines are full-size metro lines, the other ones are light metro running shorter vehicles, often with extensive elevated service.
- Separation between regional rail and metro service. Montreal is sufficiently North American to have given up on regional rail entirely, but Lyon and Marseille are investing in better regional rail, run separately from the local urban transit system but with some degree of integration.
- Light rail. France’s modern light rail systems do not originate in Paris – Nantes opened its system in 1985, suburban Paris only in 1992 – but Paris has a notable feature that isn’t common elsewhere in Western Europe: it is a mixed system with some Métro lines and some tram lines filling in the gaps. This mixed system is also present in Lyon, Marseille, and Toulouse, whereas Bordeaux, Strasbourg, and Nice have entirely tram-centric systems. But in no case is there any subway-surface running as in the United States or Germany: lines are either clearly trams or clearly metros, rather than mixtures, and it is the system that is mixed, not the individual line.
Has France decolonized?
Like Britain, France did not take its geopolitical disempowerment at the end of World War Two easily. Both countries have maintained superpower pretensions, decolonizing but trying to treat their former colonies as their spheres of influence as much as possible. In Britain, this relationship broke down – the ex-colonies were being too loud in the Commonwealth, leading the country to seek to join the EU instead. In France, this relationship remains in Africa, and notable not in Southeast Asia, where Vietnam is buildings its urban rail networks with Chinese and Japanese financing.
But France is not just providing financing to infrastructure projects in its former (or current?) African colonies. It has a permanent presence. In researching Arab rail infrastructure, Anan Maalouf has noted that Alstom has had a subsidiary operating in Algeria since 2002, which does not exist elsewhere in the Arab world. This way, French firms maintain close knowledge of the situation in the Maghreb, where incomes and productivity levels are much lower than in France, so that different methods are optimal from those common in rich countries.
Nonetheless, what they build remains noticeably French. For example, the Sfax tramway does not look too different from what Bordeaux or Nice has. The Tunis Métro looks rather like a French tramway system too, despite the name; of note, even though the Tunis Métro branches, and has some underground segments, those segments are not on line trunks and thus the system does not form a subway-surface or Stadtbahn network.
I haven’t gone too much into intercity rail, but it is worth mentioning that Morocco has a high-speed rail system, built with French technical assistance and running TGV equipment.
Does this work?
Yes and no.
The Paris system works. It is not perfect, and in particular the integration between the Métro and the RER could be better; at least one tram line should be a full metro line (a completed T3 ring), and suburban extensions should generally use the RER, with more investment in RER capacity within the city as well. That said, public transport usage is higher in Paris than in its closest comparison, that is London; Paris’s system is also superior in both overall usage and future prospects to that of another megacity in Europe, Moscow. Only Istanbul could potentially do better in the future, in the context of extremely low construction costs.
That said, Paris is a giant that casts a long shadow, which doesn’t always work well for secondary cities. Lyon, Marseille, Toulouse, and the other secondary French cities aren’t too different in modal split from similar-size British cities, and are behind Vancouver, a North American city with extensive postwar growth. German cities in the Lyon size class do a lot better. See for example data here and here.
The weird features of France, like the love for rubber tires, are not that relevant overall, but do point out that France is relatively insular, and mostly adopts domestic ideas developed in Paris rather than ideas from elsewhere in Europe, let alone Asia. (Yes, I know about Japanese influence on the initial RER; however, there have been 50 years of divergence since, same as with German tram-trains and American light rail.) This has been especially problematic with regional rail. France does not have frequent takts anywhere – even Paris only has takt timetables off-peak, running a separate schedule at rush hour, whereas the German takt plan is repeated throughout the day and the peak can only have supplemental service.
The issue is that Paris does not need to think in terms of repeating schedules, because it is so big that the RER trunks run every 5 minutes off-peak. It thinks of the RER as mostly separate trunk lines with dedicated fleets, because the primary problem is train capacity through city center. In Lyon, let alone smaller cities, this is not the main issue. There do exist a handful of individual lines running an off-peak takt elsewhere in France, but integration with urban rail remains imperfect and a comparison with Vienna, Copenhagen, Zurich, Stuttgart, and Hamburg would not be favorable. It matters that, like Britain, France has such a dominant capital that it doesn’t know how to scale down to provide rail service in a metropolitan area where if the transfers aren’t perfectly timed, people won’t ride.