Welcome back to Sunday reading. This week, let’s start with a new research paper on complexity. Oxford University researchers ask, “are big-city transportation systems too complex for human minds?”
Many of us know the feeling of standing in front of a subway map in a strange city, baffled by the multi-coloured web staring back at us and seemingly unable to plot a route from point A to point B.
Now, a team of physicists and mathematicians has attempted to quantify this confusion and find out whether there is a point at which navigating a route through a complex urban transport system exceeds our cognitive limits.
After analysing the world’s 15 largest metropolitan transport networks, the researchers estimated that the information limit for planning a trip is around 8 bits. (A ‘bit’ is a binary digit — the most basic unit of information.)
Additionally, similar to the ‘Dunbar number’, which estimates a limit to the size of an individual’s friendship circle, this cognitive limit for transportation suggests that maps should not consist of more than 250 connection points to be easily readable.
Using journeys with exactly two connections as their basis (that is, visiting four stations in total), the researchers found that navigating transport networks in major cities — including London — can come perilously close to exceeding humans’ cognitive powers.
And when further interchanges or other modes of transport — such as buses or trams — are added to the mix, the complexity of networks can rise well above the 8-bit threshold. The researchers demonstrated this using the multimodal transportation networks from New York City, Tokyo, and Paris.
Humans deal poorly with complexity and counterintuitive results. That’s an important thing to keep in mind when designing and communicating urban policies.
However, technology can help people navigate complexity. I’ve found that Google Maps, online journey planners, and smartphone apps have made it much easier to use public transport when visiting new cities. But a reliance on GPS mapping can lead to some unintended consequences, as Greg Milner explores in this New York Times article:
Earlier this month, Noel Santillan, an American tourist in Iceland, directed the GPS unit in his rental car to guide him from Keflavik International Airport to a hotel in nearby Reykjavik. Many hours and more than 250 icy miles later, he pulled over in Siglufjordur, a fishing village on the outskirts of the Arctic Circle. Mr. Santillan, a 28-year-old retail marketer from New Jersey, became an unlikely celebrity after Icelandic news media trumpeted his accidental excursion.
Mr. Santillan shouldn’t be blamed for following directions. Siglufjordur has a road called Laugarvegur, the word Mr. Santillan — accurately copying the spelling from his hotel booking confirmation — entered in lieu of Laugavegur, a major thoroughfare in Reykjavik. The real mystery is why he persisted, ignoring road signs indicating that he was driving away from Iceland’s capital. According to this newspaper, Mr. Santillan apparently explained that he was very tired after his flight and had “put his faith in the GPS.”
[…] Could society’s embrace of GPS be eroding our cognitive maps? For Julia Frankenstein, a psychologist at the University of Freiburg’s Center for Cognitive Science, the danger of GPS is that “we are not forced to remember or process the information — as it is permanently ‘at hand,’ we need not think or decide for ourselves.” She has written that we “see the way from A to Z, but we don’t see the landmarks along the way.” In this sense, “developing a cognitive map from this reduced information is a bit like trying to get an entire musical piece from a few notes.”
And now, for a break from cognitive science, here’s an animated GIF of a bicycle-storage system in Japan. This certainly seems simple enough to use:
Complexity is not just an issue when getting around. It’s also a very serious issue for housing and urban planning policy. We saw that this week, with various people, including councillors, denying that enabling more housing would improve housing affordability.
Wayne's world of economics… #UnitaryPlan pic.twitter.com/hNgoMHqTF6
— Non-motorist (@ByTheMotorway) February 25, 2016
As an economist, I cannot disagree strongly enough with this bizarre analysis. But it’s fair to say that the workings of housing markets are extremely complex and often counterintuitive. As Daniel Hertz at CityObservatory discusses, with reference to recent research, new dwellings tend to be more expensive than old ones (duh!) but they gradually “filter” down to the rest of the market:
But very little private housing in the United States was originally built for low-income people. Instead, homes built for the middle or even upper classes gradually became cheaper as they aged, as people with high purchasing power moved into trendier, more modern homes in “better” neighborhoods. As higher income households move on, the now somewhat older homes or apartments they formerly occupied are sold or rented to people with more modest incomes.
This process is called “filtering.” While the evidence that filtering is a real phenomenon has been around for a long time—the core of nearly every American city contains neighborhoods with once-luxurious homes now occupied by people of modest incomes—the first study to provide a rigorous measure of how it happens was published only in 2013. In it, Stuart Rosenthal of Syracuse University uses nearly 40 years of data from the American Housing Survey to figure out the average pace of filtering across the country, and what makes housing filter more quickly in some places than others.
Rosenthal uses the AHS to compare the incomes of people living in the same units of housing over time. He estimates that nationwide, housing “filters” by roughly 1.9 percent a year—meaning that a 50-year-old home is typically occupied by someone whose income is about 60 percent lower than that home’s first occupant.
Filtering is complex but very real. By contrast, some urban issues are pretty simple. Take, for example, the role of urban trees in maintaining environmental quality and amenity. In the News Tribune, a newspaper in Washington state, Rosemary Ponnekanti reports on “why cities need trees: the science behind a 30 percent canopy“:
Trees are vital in keeping a city’s air and water healthy for people.
The American Forests study, called “Calculating the Value of Nature,” analyzed the Tacoma-Everett-Redmond triangle using images from 1972 to 1996.
Dollar values were placed on the ability of trees to control stormwater flooding ($2.4 billion annually) and filter air pollution ($95 million annually.)
The loss, over that period, of 600,000 acres of highly canopied land meant a 35 percent increase in stormwater runoff, which affects salmon populations, pollution in Puget Sound, flooding on city streets, soil erosion and more.
“Each tree absorbs hundreds of gallons of water, filtering it through the root system so clean water goes back to the ground,” said Pierce Conservation District’s Melissa Buckingham.
And by filtering greenhouse gases such as carbon dioxide out of the atmosphere, trees contribute over time to cooling the air, as well as cooling it in real time with shade during summer.
According to California nonprofit Canopy.org, evaporation from one tree can produce the same cooling effect as 10 room-size air conditioners. That lowers the average summer temperature in highly canopied cities such as Palo Alto, California (which has 37.6 percent canopy), by up to 8 degrees compared with neighboring areas.
We like trees. But they’re not the only thing that can make or break a place that are sometimes poorly understood by policymakers. Take the case of traffic studies, which often focus predominantly on movement of vehicles and ignore potential impacts on non-motorised travellers, surrounding properties, and the public realm. In an interesting blog post, Slow Streets points out that things left unmeasured by traffic studies are often important for understanding the value of bike lanes:
Don’t ignore the public space outside of your business. It’s an asset that should be cultivated and leveraged. This asset is often overlooked by the business community since it’s not directly indoors. Currently, the sidewalks of Commercial Drive do not offer a secure and pleasant place to stay or linger. Slow Streets found that Commercial Drive is a rather uncomfortable place for walking: sound volumes from traffic registered at 76DB, the equivalent of standing 15m from a highway. We also observed the activities of over 1,000 people and found that there was an apprehension to linger and socialize with only 14% of people observed doing so…
By inviting people to stay and linger on the sidewalks of Commercial Drive, businesses could see an increase in revenue. In short, traffic calming is good for business. The sidewalks and public space outside of your business are a critical asset that can serve as a magnet to attract people. A bike lane will encourage people to spend time on the sidewalks on Commercial Drive because the public space is more comfortable. Reductions in automobile speeds and volumes reduce the noise people experience at the sidewalk.
As an aside, I wonder about the degree to which changes to our cities are shaping the way we live. Take this chart, which shows how Americans have been meeting mates over the last 70 years.
Local networks – i.e. meeting people through neighbours or family – have steadily become less important, while friends and coworkers became more important before falling off a cliff over the last two decades. Online dating has risen up to supplant most other options – a sign of a time-poor society where opportunities for personal contact are increasingly limited?
A remarkable sociology of the last 70 years in one chart. Each line tells a big story.
HT @petrmisan pic.twitter.com/r4tjTb665e
— Paul Kirby (@paul1kirby) February 15, 2016
In other areas, the adverse impacts of urban form are much more clear. Take Houston, for example. According to Tom Dart in the Guardian, one in five Houstonians are expected to be diabetic by 2040. This is a slow-motion public health disaster brought on by cheap sugar and car dependence:
Large homes sprout in the shadow of recently opened sections, promising cheap middle-class living with a heavy cost: a commute to central Houston of up to 90 minutes each way during rush hour, with minimal public transport options.
“A lot of time in Houston is spent in a car,” says Foreman, assistant director of Houston’s Department of Health and Human Services. This informs one of the Cities Changing Diabetes study’s most notable findings: that “time poverty” is among the risk factors in Houston for developing type 2 diabetes.
This means that young, relatively well-off people can also be considered a vulnerable population segment, even though they might not fit the traditional profile of people who may develop type 2 diabetes – that is, aged over 45, with high blood pressure and a high BMI, and perhaps disadvantaged through poverty or a lack of health insurance.
“You generally think of marginalised, lower income communities in poverty as your keys to health disparities but I think what we learned from our data in Houston is that we now have to expand the definition of what vulnerable is and what at-risk means. Just because we live in an urban environment, we may all indeed be vulnerable,” says Foreman.
In other words, not only its residents’ dietary choices but the way Houston is constructed as a city appears to be contributing to its diabetes problem, so tackling the issue requires architects as well as doctors; more sidewalks as well as fewer steaks.
People occasionally go on about how Auckland should be more like Houston. But the truth is that our public health system couldn’t afford it. As of 2013, 5.4% of NZ’s population was diagnosed with Type 2 diabetes. An earlier (2008) study found that our public health system spent $600 million annually treating people with diabetes. Imagine doubling or tripling that, as Houston is going to have to do.
While we’re talking about oil-rich theocracies, here’s an amusing BBC video on a Saudi Arabian sheikh’s sweet ride (WARNING: contains Jeremy Clarkson):
Also on the subject of gigantism, a Reddit user has helpfully compared several definitions of “high rise” buildings:
Lastly, I’d like to highlight two important articles on the importance of politeness and kindness in debates.
First, Lindy West writes about her experience with internet trolling / online intimidation – in particular, “what happened when I confronted my cruellest troll“. Unfortunately, some people treat online anonymity as a license to bully and harass others, especially women who are speaking their minds. This is one of the reasons that Transportblog has strong user guidelines against disrespectful behaviour, ad hominem attacks, and bigotry:
For the past three years or so, at least one stranger has sought me out pretty much every day to call me a fat bitch (or some pithy variation thereof). I’m a writer and a woman and a feminist, and I write about big, fat, bitchy things that make people uncomfortable. And because I choose to do that as a career, I’m told, a constant barrage of abuse is just part of my job. Shrug. Nothing we can do. I’m asking for it, apparently.
Being harassed on the internet is such a normal, common part of my life that I’m always surprised when other people find it surprising. You’re telling me you don’t have hundreds of men popping into your cubicle in the accounting department of your mid-sized, regional dry-goods distributor to inform you that – hmm – you’re too fat to rape, but perhaps they’ll saw you up with an electric knife? No? Just me? People who don’t spend much time on the internet are invariably shocked to discover the barbarism – the eager abandonment of the social contract – that so many of us face simply for doing our jobs.
Others, of course, are willing to bully in person. When Auckland Council called a special session on its submissions to the independent Unitary Plan hearings panel on Wednesday, it invited along a range of people to speak. According to Hive News journalist Bernard Hickey, here’s what happened when youth group representatives got up to speak:
I watched this democratic deficit exposed most cruelly when the Council’s Youth Advisory Chair, Flora Apulu, spoke to the Council about how she felt the weight of the city’s half a million young people sitting on her shoulders as she argued for the affordable housing they desperately needed from this ‘up-zoned’ plan.
She was jeered and heckled by the dozens of rich, elderly and very Pakeha homeowners sitting just metres behind her. “Oh poor you,” they shouted.
Sudhvir Singh from Generation Zero was jeered even more loudly when he said the generation of home owners sitting behind him were ‘pulling up the ladder’ of home ownership on the young of today. “Poor you,” was the response again.
That’s it for the week. Go out and be kind to someone.