looking for structure: the metro maps of Jug Cerovic

Paris-based Serbian designer Jug Cerovic tipped me off a month ago to his remarkable work on subway maps, collected at his website and since hailed at Atlantic Citylab.    If you want to geek out on beautiful detail, go to his website now.  Here, I'm interested in looking from a fuzzier distance.



His work interests me because I'm always trying to help people see underlying principles of network structure, such as the high-frequency grid in all its forms, and often contending with the seductive allure of its opposite, the seemingly endless loop.  

Cerovic's eye has picked out these forms, and fondles their contrast expertly:  He picks out a central loop in every city that provides a hint of one, organizing map after map around a geometrically perfect circle or oval.   Berlin:


His maps of comprehensive East Asian metros call out the circle line in most of them.  Beijing and Shanghai are both rigidly circle-and-spoke like Moscow, but Beijing's outer circle is far enough out to create orthogonal grid effects in relation to the straight lines it crosses.  Cerovic, perhaps sensing this, renders the loops as rectangles:


But it's hard to resist the beauty of the circle.  Tackling Paris, Cerovic seizes on the ellipsoid loop formed by Metro lines 2 and 6, rendering them as a perfect circle that seems to unify the image.  Only the color change signals that you can't go around forever.


I have long argued that the Paris metro is mostly an orthogonal grid system, with most routes in north-south or east-west paths that intersect to form logical L-shaped travel opportunities.  In fact, it's a great example of a grid system fitted to a gridless city.  Lines 2 and 6, and the more recent T3 tram that Cerovic renders as a quarter-circle, are really the only predominantly arc elements and even they function like east-west grid elements in the actual geography, 

In Madrid, Cerovic reveals the Expressionist quality of the metro network:  lots of emotive scribbles and personality quirks but without a clear structuring idea.  


The gently collapsed loop at the center reminds me of a Jean Arp sculpture.

In London, he ignores the obviously potential of the Circle Line, which despite its new tadpole shape could easily have been made into a perfect circle or oval.   Instead, the perfect circle that anchors his map is an emerging, ghostly London Overground, bristling with spurs:


I like Cerovic's maps for their stripped-down emphasis on the drama of line vs. loop.  Lines are from Mars and loops are from Venus.  They will never understand each other.  The challenge — in all the dimensions of design — is in making them dance, and helping both impulses succeed.


the economist and the “redundancy” fallacy

Today's unsigned piece in the Economist "Democracy in America" blog picks up on Tom Vanderbilt's Slate item reviewing my book.  I'm certainly grateful for the publicity, though for the record, I do believe in pleasure!

But the Economist's writer ends his piece with a commonplace of old-inner-city thinking that can do real harm when taken outside those bounds:

Ultimately, what makes public transit work is massive redundancy: lots of different systems layered on top of each other, all running at high frequencies, providing you clear information on when the next one arrives. The world's best cities, New York, Paris, London, Hong Kong, Berlin, all do this pretty well. For cities that aspire to greatness, the road map doesn't seem so hard to follow.

"Lots of different systems layered on top of each other" begs the question of whether these systems are working together — for example by encouraging connections from one to the other — or simply duplicating each other.  That is the distinction that matters.  

Yes, if you're in "New York, Paris, London, Hong Kong and Berlin" you may perceive a layering of "redundant" services, but one of two very different things is happening:

  1. The services are truly redundant in the sense of duplicating (or even competing) but the demand is so intense that they're all full, so the duplication isn't much of a waste.  This is the case with many big-city commute markets, but often not with all-day patterns.
  2. The services are actually fitting together into an integrated network, through some mix of planned connectivity and complementarity.  An example of complementarity is the simultaneous presence of services in one corridor that differ in the speed/access tradeoff.  A major Manhattan avenue, for example, may have an "express" train stopping only every mile or less, a "local" train stopping less than every half-mile, and a bus on the surface stopping even more frequently.  That isn't redundancy unless the market isn't strong enough to support all three.

Praising these super-dense cities for "massive redundancy" sends exactly the wrong message to less-dense and smaller cities.  Tell them to plan for redundancy, when their markets are insufficiently developed, and they'll spread their resources out in tangles of overlapping services none of which are frequent or attractive enough to be worth waiting for.  This is the lesson of inner Sydney, discussed in Chapter 12 of my book.

You need massive agglomeration for true redundancy to work.  Without that, you dissipate service quality too much.  This was a key failing of the privatization of the British bus industry, which gave private companies control over transit planning and prohibited them from working together to create rational connective networks, by declaring that to be collusion.  The result was a generation of frustrated riders who had to let Jim's bus go by because they had a ticket for Joe's bus, even though the two bus lines together might add up to enough frequency to actually be useful.  The last Labour government finally removed this prohibition on "collusion," allowing simple, obvious, and mutually beneficial plans to go forward, like this one in Oxford.

"Massive redundancy" may be fine if you're a megacity, though even there, its effectiveness may be a feature of the peak that doesn't translate to the rest of the day.  Anywhere else, services need to work together as a network.  Even in London, New York, Paris, Hong Kong and Berlin, that's really what's happening. 

connection-activated civic squares

A few days back I asked for examples of connection-activated civic squares, public squares that serve as both a symbolic and functional heart of the community, but where people connecting between transit lines form part of the square's activity.  I was looking for a real-world example of something like this, which is a design for a (non-existent) square in Surrey, an outer suburb of Vancouver:

  Surrey Central Plaza-1

The idea arises from the desire to have bus-rail connections happen in an interesting urban setting, rather than a typical suburban bus interchange that features an area where only bus passengers would be. 

First, I should answer this comment

Isn't the idea to reduce transfer penalties, not to deliberately increase them for other ends? Getting off the train on a cold, stormy night, I think I would resent being made to animate an otherwise deserted public square – running 200m for my bus, with my umbrella blown inside out, dodging puddles. Even worse if it was on the way to work in the morning!

Indeed it is.  I always want connection walking distances to be as short as possible.  The square above is 100m wide, so maximum walks would be no more than that, and that's not out of line compared to what you'll do in tunnels in many of the great subway systems of the world.  But I'm not sure that walking across a square is more onerous than walking along corridors or tunnels, so long as there's some reasonable alternative in bad weather.  And of course the urban designers are always telling us that visual interest makes walks feel shorter.  When walking along a typical subway tunnel lined with shops, I feel reduced to the status of consumer.  I would much rather walk across a square on a nice day.

One reason that these arrangements are unusual, and that I should have noted, is that they require buses to be organized in an inverted couplet.  In a country that drives on the right, you would expect that a westbound one-way street would be north of its eastbound partner.  That's the way two-way streets normally divide.  In this Surrey proposal, we set up the car traffic to do that but the buses to do the opposite in contraflow lanes.  That's how we got the bus stops to be on the square rather than across the street from it.  This is a great trick in situations where you already have one-way couplets of streets.  It gets buses out of traffic and puts them with their doors facing each other so that they can stop at opposite sides of a square (or even just at opposite ends of a pedestrian street or lane). 

(Portland's transit mall is a famous example of an inverted couplet — the northbound street is west of the southbound street — and if the Pioneer Courthouse Square were one block further east, it would be a spectacular example of a connection-activated square.  The mall couplet does help create an effective square at PSU Urban Center Plaza, where the mall and the streetcar intersect.)

It was quickly clear from the reader suggestions that really large connection-activated squares have to be in pretty big cities.  Even there, size can be a problem.  Note how Lyon's Place Bellecour, below, is reduced in width by a bit of landscaping.  The whole block is 250m x 170m, but the trees reduce the purely open space to about 100m wide.  At that, it's still the largest clear square in Europe, says Wikipedia.  There's room for two soccer fields in the remaining open space, three if that guy on the horse would get out of the way.

Place bellecour lyon

Place Bellecour does have a bus stop facing onto the square on the east side, but the main east-west bus movement is east on the south side, west on the north side, which in France puts the stops across the street from the square.

Many readers pointed to Berlin's Alexanderplatz, a vast and intense area that includes Berlin's iconic tower, the Fernsehturm.  Alexanderplatz is technically the northeast part of this image, but it's all intimately connected.


The interaction here is between rapid transit ("U") at the center of the image and tram and bus lines.  One of the tram lines extends northeast and northwest from just south of the rapid transit station.  As I recall some of these trams turn to stop alongside the station (so are not activating the plaza) but others do not, so some people do walk across parts of the plaza.  Also relevant are buses on both the far northeast corner of the image and on Spandauerstrasse, which is the street cutting across the southwest corner.  Greater Alexanderplatz is a series of spaces where the interaction of transit and urban life is quite intricate.

A clearer big-city example is Syntagma Square, Athens.  It's about 110m on a side, and seems to work well, though Google is a little fuzzy there:


Syntagma has an underground metro station on the east side of the image, including entrances right into the square.  Buses are organized as a couplet, and in this case, it appears to be an inverted couplet so that the buses open into the square, but I can't quite be sure.  The Athens Tram also terminates there.  The position next to the Greek parliament building ensures that the square is a symbolic center of the city and nation.

Several readers suggested Piccadilly Gardens, Manchester, UK.  I had in mind hardscaped plazas, but this one is interesting as an example of how much transit work a grassy park with a fountain can do.  It's about 120m x 90m at its widest points.

Piccadilly gardens manchester"

This is clearly a major tram+bus terminal, with lots of space taken up by end-of-line storage as opposed to just stops.  That's part of why the transit operations seem to dominate the space to a degree that urbanists are likely to find objectionable.  Note that the main pedestrian links between connecting services are paved paths across the gardens.  The landscaping is a nice way of saying "this is a park, not just a transit interchange," even as the paths serve the interchange volume.

Last among big-city examples, I'm intrigued by Insurgentes station plaza in Mexico City, which is in a roundabout roughly 120m in diameter. 

Plaza insurgentes mex

Note that the red buses appear to cycle the circle in a contraflow lane, i.e. clockwise where all other traffic is counter-clockwise, so that they open onto the central plaza.  (UPDATEI am now advised that they are operating with-flow, counter-clockwise, but in their own lanes, and have doors on the left that enable them to open onto the plaza.  The two silver-roofed structures are their main stops).  Obviously, this is a massive bus-rail connection point.  The red buses are from the city's Bus Rapid Transit system.  This is certainly enough pedestrian volume to activate a space, and indeed it looks as though some kind of merchant activity is going on.  But of course a roundabout is inevitably more of an island than a heart, as you'll need to go underground, through the subway station, to cross safely to any part of the surrounding district.

But when we step down to smaller cities, or to outer locations that aren't major transit hubs, the successful squares are quite a bit smaller.  Several readers praised Mont Royal station plaza in Montréal.  The subway station is on the west side, with bus stops on the east and north sides.  This looks like a case where terminating buses are actually looping around the square. 

  Mont royal, montreal

But it's only about 50m wide.  Many readers suggested connection-activated squares on this scale, often in secondary nodes of big cities or in suburban areas, especially in Europe.  Many such squares were mentioned, but Stockholm's Odenplen is typical.  And even in North America, small open spaces, usually  less than 50m on a side, are common at some subway stations; Vermont/Santa Monica station in Los Angeles and the two Mission BART stations in San Francisco come to mind.  Another example, at a simiar edge-of-downtown scale, is the PSU Urban Center plaza in Portland, which handles interactions between an inverted couplet of north-south buses and an east-west streetcar.  The open space there, too, is less than 50m on a side.

So to sum up:

  • An obvious larger design point is that civic squares have to be scaled to their catchment area.  The bigger the city and the more central their role in it, the bigger they can be.  For squares that aim to serve a smaller suburban or neighborhood node, the squares are smaller, usually less than 50m on a side.  The plaza we sketched for Surrey (at the beginning of this entry) was probably too big.  Place Bellecour in Lyon a totally open space of 200x100m with only a statue as furniture, probably is too big.
  • At all scales, these squares can work as multiple-purpose plazas while also serving transit connections, and there seem to be many examples of these two functions supporting each other.
  • Inverted couplets are rare but work well with public squares.  The inverted couplet is a key unappreciated feature of the Portland transit mall. 

Thanks to everyone for contributing to this adventure!  I'm sure there are many other great examples I haven't mentioned. 

This work is important to me because many designs for great highrise urban nodes at rail stations collide with the needs of connecting and terminating buses, and it's often tempting to push the buses away.  These examples, at a range of scales, capture how transit connections and urban life can happen in the same place, and indeed support each other.  Links to other great examples are welcome!

Berlin: Serene Images for a Hiatus

DSCF1431 It’s going to be quiet the rest of this week on Human Transit.  I’m in Canberra all week doing full days of meetings to brief various stakeholders about the Strategic Public Transport Network Plan that I have been doing for them over the last two years.

While waiting for new material, these images from Berlin’s Märkisches Museum U-bahn station may serve as a calming visual hold-music.  (Click to enlarge and sharpen.)  They’re a series of artworks clearly based on maps of Berlin from different times of in its history.  German Wikipedia tells me that they’re the work of Jo Doese, Karl-Heinz Schäfer, and Ulrich Jörke, and that they were completed in 1988, under communist rule, the year before the wall came down.  I enjoy their Deco-like cool and serenity.  (click below to continue)

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Viaduct Love in Berlin

The current generation of urban designers may like to complain about NIMBYs, but urban designers and NIMBYs can be counted on to agree on one thing:  Elevated transportation infrastructure is a bad thing in an urban setting.  Urban design today focuses on activating the ground plane and maintaining its visual connection to the sky.  Even pedestrian bridges are out of fashion, while a new continuous elevated structure would be hard sell in the urban core of almost any major city.  The Seattle Monorail Project (1996-2005) proposed a very thin elevated structure, but even this was a flashpoint of controversy when it got close to existing buildings.

It may be true that we don’t know how to build viaducts anymore and that the freeway era has traumatized a whole generation into reacting badly to absolutely anything new up in the air.  And I’m not sure that’s a bad thing, but …

But before we decide for sure, take a walk with me along Berlin’s Stadtbahn.

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Berlin’s New Micro-Subway: A Short Architectural Tour


Earlier this year, Berlin’s U-Bahn opened its newest segment of subway, a 1.1 mile three-station line connecting the main rail station to the Brandenburg Gate.  It’s temporarily called the U55, but it will ultimately become part of the expanded U5 (see network map here).  From the Gate, the line will continue east under Unter den Linden, Berlin’s main processional boulevard, to Alexanderplatz, the former East Berlin downtown and one of Berlin’s most important hubs.  (From there it will continue to the eastern suburbs as the U5 that already exists.)  This is such an important segment for Berlin, both practically and symbolically, that it´s remarkable it´s only now being built.  (The Transport Politic reviewed the political history here.)

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Transit in the Fast Lane: The Access Challenge

When you’re trying to run quality transit in a mixed-traffic situation, and you have a street with two lanes of traffic in each direction, the best practice is for transit to run in the faster lane, the one further from the sidewalk.  We see this most commonly with streetcars, but it’s true of any mode of street-running transit.  That’s because the lane closer to the curb is often delayed by random car movements, including cars turning, or trying to parallel-park, or doing pickup and dropoff.  So long as the fast lane is separate from any turning lanes, it’s the lane where you’ll get the best travel time in mixed traffic.

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