Author Archive | Jarrett

the slate.com review

Today at Slate.com, Tom Vanderbilt, author of How We Drive, reviews my book Human Transit.  It's a friendly review and I much appreciate it.  Followup thoughts on the review in a day or two.  Meanwhile, for the record, I do believe in pleasure!  

portland: balance the budget yourself

Portland's Tri-Met faces another horrible funding shortfall this year, but they've come up with a good survey tool to engage the public in their decisions about what services to cut.  It's one of those "balance the budget yourself" tools that's becoming increasingly necessary to bring voters into contact with reality about government budgets.  

If you live in Portland, you should definitely work through the survey and send them your own balanced budget and comments.  If you're not in Portland, is your transit agency communicating about its trade-offs this well?

sydney: monorail soon to be scrap metal?

DSCF4148

The state government that rules Sydney is giving signs that it's ready to tear down the city's monorail, ostensibly for a rebuild of the convention centre but also to remove some obstacles to surface light rail, including game-changing new line down the middle of Sydney's CBD spine, George Street.  Jake Saulwick has the story in today's Sydney Morning Herald.

A source from one consortium [bidding to build a new convention centre] said no decision had been made ''but the word from the government is 'don't let the monorail constrain your thinking' ''.

''Conversely they say the light rail is quite important.''

This could be read as a story about big bad developers destroying a crucial transit resource, but it's not. The Sydney Monorail, opened in 1988, is the red line in the map below: a one way loop connecting the CBD to the nearby tourism-entertainment-convention district of Darling Harbour:

Sydney_metro_map
Map by discoversydney.com.au

Like many transit toys, it was built cheaply on the assumption that the joy of the technology itself would transcend its lack of usefulness.  Its most obvious use is for travel between the convention/exhibition area on the west side of the loop to the city centre in the east, but the key stations on the west side of the loop, serving the convention/exhibition area and Paddy's Markets, are attached to parking structures, offering an unattractive walk to the destination itself.   The fare is $5.00.  Meanwhile, it's less than 1.5 km (1 mile) walk from one side of the loop to the other, mostly along reasonably pleasant paths that lead to the front door of your destination, though to be fair there is one elevated waterfront freeway in the way.

I lived and worked in inner city for five years, crossing the monorail's service area on foot several times a week.  Twice in that time, in very bad weather, using the monorail made sense to me.

The monorail is a barrier to light rail, indirectly, because its pillars form a bottleneck in a potential north-south traffic lane on Pitt Street, and this lane could be useful in rearranging street uses to create room for a light rail line the whole length of George Street, the largest continuous north-south street in the city's core.  Light rail is being designed to be useful.  It will be in an exclusive lane (which is why it's not being called a "tram") and it will form the common CBD segment for several lines branching out in several directions, serving high-demand corridors in the inner city.  Its high capacity (in the sense of passengers per driver) and its two-way service in high-demand places will make it a real transit service, unlike the tiny one-way loop of the monorail.

Next time someone wants to introduce a fun new technology into your city using a one-way loop, remember: 

  1. Very few people really want to travel in circles.
  2. Except for tourists and others travelling for pleasure, most people need direct service in both directions, which loops don't do well, and …
  3. Loops are intrinsically closed, turned inward on themselves, impossible to extend without disrupting existing travel patterns.  That's why one-way loops are never a good starter project for a technology that's expected to expand its relevance in the future.

For more on those principles, see Chapter 4 of Human Transit.

Finally, monorails are fun to ride, but most people experienced this one from being underneath it.  This was just a single beam for one-way loop service, causing all the problems above, but it was still much-disliked, especially in the narrow streets of the highrise core where it added to the sense of overhead weight above the pedestrian.

DSCF4171

DSCF4174

To be fair, it's less oppressive than, say, the Chicago "L" or many other downtown viaducts.  A transit advocate might fight hard for exactly this kind of visual impact if it was the only way to get useful two-way service through a high-demand area.  In fact, one of the best uses of monorail is in historic and very crowded areas where the combination of archeological and ground-plane impacts of any transit service simply mandates elevated as the least bad solution — parts of New Delhi, for example.  But the Sydney monorail had few of these benefits.  Perhaps it was just a toy, and Sydney has outgrown it.

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:

Traveltime-1

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

Dc-metro-map2

and a spatial one

  Washington-dc-metro-map-with-city1

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.  

Bad-tube-map
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 …

 

Iowa-GOP-vote-map

… 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.  

Statecartredblueakhi

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.

new york ferries: the first smartphone payment system for transit?

Ny waterway

That's what I'm being told about the new fare system at the Hudson River ferry operator New York Waterway.  You can now buy a ticket using your smartphone and then use the phone itself to present the ticket to the fare reader, similar to the "digital boarding passes" already used by airlines.  No paper required.  Expect this to spread in high-end commuter markets.

It would be great to see this spread in urban bus transit, where boarding times are still a dominant problem, but that will rely a very easy-to-use app and compatibility with smartcard media now under development.  My guess is that we'll get a ubiquitous commercial smartcard-creditcard first, which will do the same job.

Photo: Hoboken Condos

singing the metro

UK reader Adham Fisher, who recently visited all 301 Paris Metro stations and wrote a song about the quest, announces a musical project:

[I asked] different musicians to submit songs about various metro systems around the world. The result is the Metro EP under the collective name 1000 Stations. We toured it to Paris last month and hope to release it early next year. The project may be followed here: twitter.com/1000stations .

It would be great to see more musicians trying capture the beauty of networks in musical form.  Music is mostly math anyway — especially electronic music — and as many composers have discovered, you can make great music simply by exploring music's mathematical structure.  Geographic networks have structures too, that could be explored by analogy at various degrees of abstraction or popularization.  

Storing and transmitting geographical information in songs is not a new idea, especially for premodern cultures.  That's part of what Australian Aboriginal songlines are, for example.  

how frequent is freedom?

“Frequency is freedom” is one of the slogans I’ve used on this blog and in my book.  Charles Montgomery, author of the forthcoming book Happy City (Farrar, Straus, and Giroux 2012), asks “how frequent is freedom?” and goes on …

I’m writing in hopes you can answer a particularly vexing question. … I have tried and failed to find empirical evidence showing the transit frequency at which users can simply show up without consulting schedules or feeling anxious. All I have found are dense reports about ‘elasticity’ and then a range of planners’ ‘gut feelings’ suggesting anywhere from 5 to 15 minutes.

Have you found any evidence suggesting a certain headway crosses a threshold of reducing the friction and perceived difficulty of transit enough to change the game at any stop?

Elasticity is the ratio between an outcome and the variable that’s supposedly affecting it.  We say that the “elasticity of frequency is 1.0” if every time you double a frequency, ridership also doubles.  If ridership goes up only 80% when you double a frequency, that’s called an elasticity of 0.8.  Obviously, modelers of elasticity have to sort out a lot of different variables and seek elasticities for each.  You’ll find discussions of elasticity of frequency, fare, travel time, and a range of other transit variables in the literature.
 
But the concept of elasticity implies that there’s some linear relationship between frequency and ridership outcomes, describable by a ratio.  This in turn implies that frequency affects ridership in the same way at all levels of frequency.  Most transit planners know that isn’t right, that there’s a “phase-shift” in the relationship at the point where the customer stops planning their life around a timetable.  

 

It’s very tough to make a hard case, because the only “hard” data on these things comes from observing the effects of frequency changes, and as you can imagine, other things are usually happening at the same time as a frequency change.  It also takes a year to see the results of any service change fully manifest, and by then other stuff has happened that muddies the data.

 

So I’m in the “planner with a hunch” category.  I can tell you that the top-performing all-day routes in most networks I’ve studied (top performing in riders per unit of service) are mostly high-frequency routes in dense areas.  Both the frequency and the density are important.  And in most cases, the threshold of “high frequency” is around every 15 minutes all day.  Lower frequencies are usually associated with much lower performance.

 

One big caution, though, is that our tolerance for frequency varies with trip distance.  A 15-minute wait for a one-hour ride feels a lot different from a 15-minute wait for a three-minute ride.  So we generally aim for higher frequencies where we’re aiming for shorter trips.  However, frequency is so expensive that it’s often affordable only where the capacity is required.  

 

If any other reader has seen the definitive study on this phase-shift let me know.  My hunch is the case will be made by comparing different frequencies of service through similar land use, rather than by comparing the results of frequency changes.  But again, that’s a hunch, and defining “similar land use” presents its own thicket of difficulties.

 

switzerland: making “when” visible

Much of transit's complexity arises from the difficulty of saying and remembering when it runs.  Route maps can be made pretty simple, but most urban North Americans (and Australians) have been taught that schedules are intrinsically complicated.  You either bypass them using trip planners or realtime information, or learn to enjoy wading through vast tables of times glittering with footnotes ("deviates via Hilltop Community Center on Thursdays").

Schedules are intrinsically complicated if running times change throughout the day, as is the case in many transit services that are stuck in mixed traffic.  But when you have an exclusive right of way, like a busway or separated train track, and you want the network to be simple, you can achieve beautiful repeating patterns like, well, this … (click to sharpen)

Swiss rail slice

It's a slice of this new diagram of the entire Swiss railway network, showing the repeating hourly patterns on which the entire network runs.   [Download PDF]    The notation takes a while to figure out, but there's a legend in English, French, and German that will talk you through it with typical Swiss clarity.  But for example, suppose you're at Grenchen Süd on the left side of the image, and you take an eastbound local train (the black line that runs across the middle of the image).  It arrives Grenchen Sud at :30 after every hour departs a minute later.  You'll then stop at Solothurn West at :42 after the hour and arrive Solothurn at :44.  Stay on the train and you'll get to Niederbipp, but if you want to go to Wiedlisbach, on the local line north out of Solothurn, you'll have a nice connection.  That train leaves at :48, only four minutes after you arrive.

This regular pattern happens every hour, all day, every day, and similar patterns cover the entire country.  The whole rail network is an interconnected structure of times, not just lines, with schedules built around each other to optimize connections as much as possible.  The core enabling idea is the regular hourly pattern of almost everything. That's what assures that (a) you can remember the schedule and use it regardless of when you decide to travel and (b) the connection timing is the same regardless of which trip you're on.

Download the full map if you dare.  The legend itself is a work of art.  I stared at it happily for half an hour, but I'm a fallen geek.  A true geek could kill an afternoon.  

And of course, the Swiss do the same thing at the urban transit scale.   Here you can download a similar map for the Zurich S-Bahn. (Legend only in German, but it's similar to the main map, which has English.)

No, I'm not saying that all public information should look like this, only that regular patterns in a timetable are a radical act of simplification, one that suddenly makes the whole day's service graspable in a couple of numbers.  Where these regular patterns are possible, they're worth fighting for.

happy holidays

It will be quiet here over the holidays, as I get (semi-)(re-)settled in Portland.  Back just after New Years, if not sooner.