Human Transit

redistorting maps: the virtue of cartograms

M. V. Jantzen has designed a fun tool that let's you rearrange a subway map to show actual travel times from where you are.  It's featured today at Greater Greater Washington.  Here's Washington DC Metro viewed from Ballston station in Virginia:

Jantzen calls this a "distortion," and with that I would disagree.  It's a redistortion, because as Mark Monmonier explains in his classic book, all useful maps are distorted.  Here's a whole page of Washington Metro maps, including the classic diagram ...

and a spatial one ...

 

Spatial maps are about spatial distance, and that's often, but not always, what matters.  The classic London Tube map is useful as a diagram, for example, but it can also undermine people's actual mental understanding of the geography of London.  

Source: Transport for London

Of the above image, Kerwin Datu writes: 

Bayswater and Queensway are 190 metres apart on the same street, Regent's Park and Great Portland Street 230 metres apart on the same street. But anyone going from Oxford Circus to either Bayswater or Great Portland Street would be persuaded that they had to take two trains to complete their trip.  ... This is unacceptable in a low-carbon age, and with trains packed to the gills in peak hour ... 

Back to the biggest picture point:

Maps that show one useful geography correctly seem so naturally authoritative that we can easily overvalue them when we really care about something else.  

Consider the way spatial geography is misused -- by almost all media -- to represent population.  If you think this is a useful map of the recent Iowa Republican caucuses ...

 

... then you're misreading space as population.  The visual impression of dominating such a map arises from appealing to sparse rural voters who influence large spaces on the map.  Winning an election is something else.  The guy who won the orange counties did as well as the guy who won the purple ones, because the orange counties are where most people live.

(Updated) Back in the 2004 election, some smarter cartographers attempted maps (technically cartograms) in which each bit of area represented a fixed number of voters.  (Thanks to Niralisse for finding them for me!)  The US was reshaped into something looking like an angry cat wearing a corset, the mountain states reduced to almost nothing while the West and Northeast were enormous blobs.  

It took a while to get into, but it was an accurate visualization of what voters did.  It was a useful redistortion, arguably a net reduction in distortion, because when describing population-based data, a spatial map like the Iowa caucus map above is a distortion too.

Inevitably, as technology customizes everything around our individual narcissism perspectives and preferences, we'll get more used to "just for me" maps, maps that show how the universe really does revolve around ourselves.  These are crucial for their purpose.  I've especially praised this one, which shows where you can get to on transit, in a given time, from a point that you select.  

Ultimately, a clear vision of your city, your transit system, and your place in the world can only come from being able to move quickly between different kinds of maps, so that you're reminded at each moment that no map tells the whole story.  We must be able to redistort for ourselves, in real time.  If everyone had the tools to toggle quickly among different kinds of diagrams, they might even get over the notion that a spatial map tells you anything about an election.

sydney: new efforts at frequency mapping (guest post)

Kevin McClain is currently a Project Officer at Easy Transport, the Regional Coordination Office for Community Transport in Northern Sydney.  He holds a masters degree in Transport Management from the University of Sydney.

Recently there has been a lot of discussion about Frequency Mapping on Human Transit starting with this post. Here in Australia we have seen frequency maps for Melbourne and Brisbane, but other than this map, we haven’t seen one for Sydney. Inspired by the efforts so far, I set out to try and make a frequency map of the services in Northern Sydney, the region where I currently live and work.  This effort was also driven by the desire to reduce the number of resources a transport user would need to consult in order to plan a trip.  Currently there are seven different system maps for services in the Northern Sydney Area alone: five bus maps (each covering different areas), one rail map and one ferry map.  Ultimately I ended up developing two maps: One frequency map of all of the services in Northern Sydney and one map of all frequent services across all of Sydney.

I work for Easy Transport , which provides transport information for seniors and people with disabilities. We also serve as the regional coordination office for Community Transport in the Northern Sydney Region and provide travel training to residents.  Our Northern Sydney map was developed to be a tool that could be used by the travel training program and potentially help promote our service. 

One of the challenges I have struggled with is the fact that there are a variety of service types in Sydney (buses, trains, ferries, and light rail) and people seem to want to be able to tell the difference between the service types when they look at a public transport map.  This makes frequency mapping more difficult.  In the Spokane map, all services are provided by bus.  There is no need to show service types.  Creating a map that shows service types and then shows frequency within each of those service types quickly gets complicated. 

For the Northern Sydney map I started by showing bus, train and ferry frequencies at the following levels 1-15 min, 16-30 min and 31-60 minutes.  This quickly proved to be too much, therefore the train lines were modified to show only stations that had frequent services (1-15 minutes) and stations that didn’t (Click here to download high resolution PDF.)

One alternative is to show only frequent and infrequent services (1-15 minutes and 16-60 minutes). While this reduces the amount of information available, it also makes the map more legible.  (Click here to download high resolution PDF.)

The map of all frequent services across all of Sydney is less complicated.  Only the suburban train services and frequent bus services are shown.  [JW:  Sydney has no frequent all-day ferry services.]  Train frequency was again shown on a station by station basis.  This version has the same colours for the train lines as are used in the CityRail map.  (Click here to download high resolution PDF.) 

While this alternative does not have the colours of the train lines.  (Click here to download high resolution PDF.)

One of the main points of both maps is to show where the frequent bus services are in Sydney.  While train frequency is also important, there has been a recent expansion of frequent bus services across Sydney with the introduction of the Metro bus services (in red on the map of all frequent services).  I think that it is important to show how these new services, along with existing frequent bus services, fill in some of the gaps.

Each of the maps show the trade-off between providing more information and a clear map that emphasizes the frequent services.  Try planning a trip on one version of the map and then the other.  Does the level of information provided affect the routes you chose?  Are you able to figure out where the routes are going?  Are there areas that are particularly confusing? Which version of each of the maps do you prefer?

These maps are still in draft form and I would welcome comments and suggestions about how the maps might be improved.  And yes, there are errors on both of the maps.  Corrections or any frequent routes that I might have missed are also welcome.   You can send me feedback either by commenting on this post or by emailing me at kevin@easytransport.org.au. 

 

walkscore's new apartment search functions

Walk Score, an admirable Seattle company that invented the "Walk Score" now widely used in the US real estate business, now has an improved app for their transit travel time tool.  That tool, which I use in my own definition of "personal mobility," shows you how far you can travel on transit from a chosen point in a fixed amount of time.  For example, here's how far you can go in 15, 30, or 60 minutes from San Francisco Civic Center, at least on agencies that participate in Google Transit:

You can find something similar at Mapnificent.net.

Walkscore now has a fine new set of presentation tools that combine this information with real estate listings, so that you can search available apartments based on commute time to a destination of interest.  Couples can even search for locations that optimize both of their commutes.  For example, if one of you works in downtown Seattle and the other across the lake in downtown Bellevue, Walk Score discovers that if you want to equalize your commutes, you should live in the University District, where the blobs of access from the two workplaces overlap. Walk Score will even show you available apartments there.

(Of course this service needs to be expanded beyond rentals.  Some people who are buying a home may care about similar criteria.)

All this is a step toward a more universal use of this tool that allows anyone (people, businesses, institutions, government services) to see the transit access consequences of where they choose to locate.  Many places are simply inaccessible by any efficient form of transit, so people need tools for avoiding those places if they want transit to be part of their lives, or that of their employees, customers, or clients.  That's especially important because some of these places are cheap, but may not be as cheap as they look when you consider the transport costs they impose.

I'm also interested in using this tool to generate a more factual two-digit "Transit Score" than the one Walk Score currently promotes.  More on that here.

transit planning for fictional universes

As longtime readers know, I would reject the claim -- repeated today by Benjamin Kabak at Second Avenue Sagas -- that "in fictional universes, subway systems do not have to make much sense."  So I would not be as quick as he to excuse the incoherences of the newly announced Gotham Transit Authority Map:

While Batman himself has other transport options, many fictional people are going to need transit to assemble the necessary crowds and populate the alleys and crevices of his plots, and those people certainly need better than this. 

Perhaps I nitpick because I was raised on higher-grade science fiction and fantasy, in an era when authors felt compelled to think about every relevant dimension of their world.  In those days, you didn't worry so much, while exploring the fictional world, that if you leaned on a tree it might collapse like a flimsy cardboard set, revealing a blank space that the author hadn't seen fit to imagine.  JRR Tolkein knew all the personalities and travails of every king for the last several millennia, and of many mythical ages before that.  You could at least expect an urban imaginer to be sure the transport system made credible sense.

Even more important than the fictional universe, of course, is the hypothetical one, where even more care is required!

Are you an aspiring science fiction writer or screenwriter?  If so, have you hired a transit planner yet?

san francisco: frequent network map refined

SF Cityscape has done a refinement of their excellent frequent network map for San Francisco, one that highlights the basic structure of the network that's useful for impatient people at all times of day.  You can download the full GIF and or PDF here.  A slice:

The map is so cool that I feel liberated to nitpick.  Some other basic principles for maps of this type, worth considering:

• Limited stop service (numbers with an L suffix in San Francisco) is substantially faster than local-stop, so I think it deserves its own color, possibly shading gradually to the local color when the limited segment ends, as 71L does west of Masonic.  A separate color would also clue in the viewer that those lines stop only at the points indicated, while locals stop at more stops.
• To further clarify the previous point, I'd come up with a really tiny stop symbol to mark all stops on local-stop services -- maybe labeling them in smaller print or not labeling them at all.  This would give a visual indication of frequency of stops that would give an accurate view of relative speed.  You really do not want to ride all the way across the city on Line 1, which stops every block or two.  Such a notation would help the limited stop services -- which really are useful for going all the way across the city -- stand out more effectively.
• The mapmaker has followed the transit agency's practice of marking only wheelchair-accessible stops on the surface streetcars such as N.  In fact, these line stop every 2-3 blocks, so I would be inclined to mark all stops, maybe using a notation like that above.  I'd also advocate separate maps highlighting issues that matter to disabled persons.  (Has any transit authority published special maps or online map layers specifically for people in wheelchairs etc, as an alternative to including all this information on a main system map?)
• I would also be inclined to emphasize that surface stops around a rapid transit station are indeed AT that station, so for example I would extend the Van Ness and Civic Center station bullets to encompass the adjacent bus stops rather than giving those stops separate coordinate names.  This is especially important on schematic maps because the user is wary that a small space on the map might be a large distance.

But again, I can nitpick usefully only because it's a really great map!

the metro as metaphor

Now and then, advertising seizes on the image of a classic subway map, using it to organise some other set of ideas.  From the Metro Wine Map of France:

The Metro station stands for some distinct thing that we should learn to distinguish from other things nearby -- fine-grained appellations in this case.  The brightly colored subway lines are categories that we should also understand -- in this case, the wine regions of France. Somehow this metaphor seems to satisfy, over and over, as a way to bring a certain je ne sais quoi to a topic. 

(Absentmindedly, I begin to sketch a radial metro network converging on a central station complex called "Plants in my garden."  A bright blue line called "Heather Family" departs from the Cassiope platform and heads outward via stations called Vaccinium (blueberries/cranberries) and Gaultheria before swerving toward a terminal loop of scenic Rhododendron stations.  A bright red line called  "Rose Family" departs from a platform called "Rosa" and heads outward via stations called Rubus (alight here for blackberries and raspberries), Fragaria (strawberries), Pyrus (pear) and Malus (apple) [those last two stations too closely spaced, really] before reaching its terminus: Prunus, the cherries, plums, apricots and peaches.)

Why does the metro line serve as  such an excellent selling or organizing metaphor?  Conjecture: it suggests speed, order, power, reliability, a larger design that gives meaning to experience, and an urban(e) sense of excitement (as opposed to the rural excitement of the "open road").

Of course, a true transit network functions only through the interdependence of its lines, like the lines of Daniel Huffman's transit-map of the Mississippi River system. 

 

 But the metro-as-metaphor doesn't seem to need that.  The "wine-metro" map at the top of this post is all disconnected but still seems to sing, at least to its intended crowd.

What is it about the rail transit as a metaphor?  How could we corral this metaphorical power to get some of the real thing built?

good network maps: clear without color?

As I mentioned two days back, the new Spokane, Washington network map [Full PDF], designed by CHK America, is exceptionally clear in presenting the layers of the network so that you can see all of the following at a glance;

• The network of frequent services, useful to you if you aren't willing to wait long.
• The network of all all-day services (frequent or not), which is the total network if you're travelling midday.
• Supplementary express services, mostly peak-only, that are likely to be useful only to the regular peak hour commuter.  These always contain a high degree of complexity, so they must be presented in a way that visually recedes from the rest of the network, so that the all-day network is clearly visible.

The key point is that each layer is never allowed to distract from the ones above it. 

But it has one other important feature that I should mention: If you look closely, you'll see that its content is still there if you copy it to black-and white. Line widths and styles distinguish all the service categories from each other.  The only exception is the distinction between "Shuttles" and "Frequent Routes", both wide lines, and this matters less than it seems because the shuttles are frequent too.

All this is relevant not just because the world is still full of black-and-white photocopiers, but also because of color-blindness.  Matt comments: 

Recently I noticed playing around with Scribus, the Open Source Desktop Publisher (http://www.scribus.net) that "Scribus has a well developed tool, the Color Wheel plug-in, which helps to guide you selecting complementary colors, as well as visualize colors seen by folks with certain kinds of color-blindness.". So turning on an option for the three or four different types of colour-blindness lets you see what the colours look like for someone with each type.

Perhaps there is a chance that in the future a pdf viewer could incorporate something like that, such that bus maps (mostly they're rendered into pdf) and anything else in pdf could be seen as if you were colour-blind. Then the bus companies could experiment and release colourblind friendly maps.

All good, but the simplest solution for color-blindless issues is to design maps so well that the information is all there in line weights and styles, so that the color is supplementary -- very, very helpful for those who can see it but not essential.  The Spokane map does this. 

The current Portland map also tries to do this, with a different line-weight for each of its four layers.  The four layers are:

• Light rail:  colored line with black outline.
• Frequent Bus: heavy solid colored line (and, if you look really closely, a yellow-shaded line number)
• Basic Bus: slightly thinner colored line.
• Peak-only: dashed line.

Portland's TriMet uses different colors for different lines, but if you copy it to black-and-white you should still be able to make out these four line weights (though not, of course, the feeble yellow shading of frequent line numbers). 

I agree with many observers that the distinction between frequent bus and basic bus is insufficiently strong on the Portland map, whereas the Spokane map shows this distinction dramatically.  In the past, when I've tried to use the Portland map as an example of clear delineation of network layers, I've been told that the distinction just isn't clear enough, so now I'll use the Spokane map instead.  Still, Portland's intention is clear enough.

 

spokane: a very clear network map

Spokane Transit (Washington USA) has a new network map out that is one of the clearest I've ever seen. It carefully delineates not just frequent services from infrequent ones, but also presents cases where basic infrequent lines combine to form frequent segments, and ensures that peak commuter express services are visible but can't distract from the clear all-day pattern. The whole thing in its full glory is here: Download Spokane 2011 map.  The legend, too, is both clear and wonkish at the same time.

Congrats to Spokane Transit for designing this map for the public. 

Full disclosure: I was the lead planner on a restructuring study for Spokane Transit back around the turn of the century, and if I remember right, our project invented the continuous two-way frequent loop of Lines 33 and 44.  (The loop is closed on the west side as Line 20, as shown on the full PDF.)  Despite many excellent improvements (and some sad service cuts) since then, it's great to see it still operating.  

This kind of two-way loop is often useful as a way to combine radial lines and grid elements into a single service.  Line 33, for example, intersects Line s 24, 25, and 90 in a grid manner, one line north-south and the other east-west, allowing for a range of L-shaped trips via a connection at this point.  However, Line 33 also flow through so that the same segments can also be experienced as radial; if you stay on the bus, you'll get downtown eventually, and to a lot of other useful destinations. 

I sometimes caution against excessive attachment to loops.  In some contexts, with far more financial resources, I might applaud the breaking up of this loop, as I did of London's Circle Line.  Given the extreme financial pressure on US transit agencies, though, I would contend that Spokane's frequent loop was an efficient solution, maybe even an elegant one.

UPDATE:  The next post on the Spokane map, looking at colorblindness issues and comparing the map to Portland's, is here.

maps and aesthetics: washington's hidden spiral

Transit maps always express a choice about how you see the city.  Do you want to show the city in its geographical detail?  Or do you want to be able to show the structure of the transit system, which involves expanding some areas and reducing others, often leading to distortions of scale that mislead the geographically-minded rider?  Like many, the classic Washington DC Metro map does this, shrinking outer distances and exploding inner ones.

Structure can be rendered many ways, and once you're free of literal geographic scale, it's tempting to create some other visual logic.  Do you want to emphasise the concentric quality of your city, or do you want it to display many equally important points?  Which is bigger, the lines or the stations?  Do lines meekly serve stations, or are stations mere decorations on lines? 

Even more basic, what kind of structure makes you happy?  The designers of the Wellington, New Zealand transit map like diagonals, rounding all routings off to the nearest 45 degree angle.

 

It sacrifices certain geographical information to show the system in a certain pleasing way, which is fine. 

Point is, you can find any balance of geographical accuracy, systemic clarity, and sheer visual pleasure, and still be accurate.  As for whether it's useful, that depends on the audience and purposes.

So there's nothing technically wrong with mapping Washington DC's metro system like this (follow link for sharper one):

... as Andrew Bossi does.  As a system map, it's a strong visual choice, but it's not inaccurate!

what maps should be at stops and stations?

Yesterday I linked to a fine polemic by Kerwin Datu of the Global Urbanist, regarding London's much-imitated wayfinding system.  Datu reserved particular scorn for the "spider maps" presented at certain stops and stations, which show you only the bus lines that emanate from there.  Maps like this one.  (This is actually the west half of a map showing bus routes from the bright yellow area where the map would be posted.)

 

Datu's quip again:

These maps, which TfL call 'spider maps', fail at the very first task: helping you identify your destination. Normally, once you've found where you're going on a map, you work backwards to where you are. But not here. On these spider maps, you are only shown where the closest bus routes want to take you, not where you want to go. It's like the old joke they tell beyond the Pale: when asking a local for directions one is told, 'well, if that's where you want to go, I wouldn't start from here!'

The maps have many defenders, however, so I should expand on why Datu's polemic resonates with me.

First of all, of course, the London maps only make sense at all in a network where all bus lines can be assumed to be frequent.  That's true in inner London but not in many of the systems that imitate it.   If we show the customer a big, bright line direct from their location to their destination, we're conveying an impression of physical existence.  The bright line looks like a physical thing, like a road, not just the site of an occasional service event.  The whole point of Frequent Network mapping, of frequent buses and rapid transit, is that we want people to make exactly that association, to see frequent services as always there ready for them to use.

But when we use such a bright line to refer to an hourly or peak-only or nighttime-only service, we undermine that message and give a misleading impression.  Strong lines on the map suggest continuous existence on analogy with rapid transit lines, but these infrequent and short-span lines don't exist most of the time. They are probably not there when you need them.

All that, of course, is part of the case for transit maps that reflect frequency/span categories, both emphasising frequent and long-span services and specifically de-emphasising ephemeral ones like peak-only or night-only services.

But there's a more specific issue with spider maps or "buses from here" maps.  They promote single-seat rides while concealing connection opportunities.  More generally, they discourage people from discovering how to navigate the complete network.

There are contexts where this is fine.  At an outer suburban station where the only bus services are local circulators and links to a few nearby suburbs, the "spider map" allows the customer to see the complete local network without having to find it in a massive map of the whole system.

But there's a different way to organize mapping at stops/stations that might be both more truthful and would help people see more clearly (a) the structure of frequent services that are easy to use even with connections and (b) the necessary detail for all services in a local area.  That would be to provide two maps:

• A Frequent Network map for the entire city (or if the city is as big as London, maybe a large subarea of the city).   This map would have a prominent "you are here" mark, but its function would to say "here's everywhere you can go from here, on service that's available right now."  (You could simplify this map by deleting some Frequent services that would not conceivably be useful on any possible trip from "here," but if you think broadly there usually aren't many of those.)  This map would also convey a very useful subliminal message: "here is where you are in your city, and in your network."   At least for spatial navigators, this map has a useful long-term value in helping people internalize the network so that they can navigate it more freely and spontaneously in the future. 


• A local area map, showing all routes emanating from "here" (or perhaps all routes with those from "here" highlighted) but just out to a radius of several km.  The ideal radius is the distance beyond which you should usually be looking for rapid line, possibly with a connection, rather than a local bus line from "here."  The local area map should be strongly coded to highlight Frequent services and downplay peak-only and other short-span services. 

In both cases, lines exiting the map area should be labelled at the edge with any more distant destinations that you would logically use that line, from "here," to reach.  (That may not be all the places the line goes.)

This approach would not lead the customer as precisely as a spider map or "buses from here" map does, but nor would it mislead the customer as much as those maps can sometimes do.  Sometimes, the fastest way to get from here to there involves making a connection, but the connection may be very easy and very frequent, and we should resist mapping styles that conceal those opportunities. 

That's my instinct, but maybe it's just my prejudice.  What do you think?