Simple Mathematical Law Predicts Movement In Cities Around the World (scientificamerican.com) 54
An anonymous reader quotes a report from Scientific American: The people who happen to be in a city center at any given moment may seem like a random collection of individuals. But new research featuring a simple mathematical law shows that urban travel patterns worldwide are, in fact, remarkably predictable regardless of location -- an insight that could enhance models of disease spread and help to optimize city planning. Studying anonymized cell-phone data, researchers discovered what is known as an inverse square relation between the number of people in a given urban location and the distance they traveled to get there, as well as how frequently they made the trip. It may seem intuitive that people visit nearby locations frequently and distant ones less so, but the newly discovered relation puts the concept into specific numerical terms. It accurately predicts, for instance, that the number of people coming from two kilometers away five times per week will be the same as the number coming from five kilometers twice a week. The researchers' new visitation law, and a versatile model of individuals' movements within cities based on it, was reported in Nature.
The researchers analyzed data from about eight million people between 2006 and 2013 in six urban locations: Boston, Singapore, Lisbon and Porto in Portugal, Dakar in Senegal, and Abidjan in Ivory Coast. Previous analyses have used cell-phone data to study individuals' travel paths; this study focused instead on locations and examined how many people were visiting, from how far and how frequently. The researchers found that all the unique choices people makeâ"from dropping kids at school to shopping or commuting -- obey this inverse square law when considered in aggregate. One explanation for this strong statistical pattern is that traveling requires time and energy, and people have limited resources for it.
The researchers analyzed data from about eight million people between 2006 and 2013 in six urban locations: Boston, Singapore, Lisbon and Porto in Portugal, Dakar in Senegal, and Abidjan in Ivory Coast. Previous analyses have used cell-phone data to study individuals' travel paths; this study focused instead on locations and examined how many people were visiting, from how far and how frequently. The researchers found that all the unique choices people makeâ"from dropping kids at school to shopping or commuting -- obey this inverse square law when considered in aggregate. One explanation for this strong statistical pattern is that traveling requires time and energy, and people have limited resources for it.
Well, in the US... (Score:4, Funny)
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That seems like a lot of coffee joint visits per day. Do you do any work or on-task thinking on the way to/from the coffee joint? Has your employer considered putting a decent coffee joint closer to you? Perhaps even going so far as to put a coffee maker in the break room?
Re:Well, in the US... (Score:5, Interesting)
One place I worked we had half decent coffee making facilities on-site, but I preferred to walk into the village anyway. Getting a bit of exercise is good for you and also helps clear the mind a bit. When I was stuck on a difficult problem or having trouble making a technical decision I'd often go for a walk to ponder it.
I do the same now I work from home, although there aren't many good walks around here. There's a very friendly cat who lives nearby so I usually go see if he wants some fuss.
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I think people who live in tract homes enjoyed their pre-COVID commutes because they gave them a change of scenery.
As working from home becomes permanent, people may start to demand both urban amenities and also nature trails within walking distance of home. It will be interesting to see how COVID affects city planning. Perhaps newer communities will look more like the kinds of towns that we used to build before the autom
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The biggest issue I have is that the UK is largely a soulless clone town and there is little point going to most places. It's hard to find the motivation to do stuff because there isn't much stuff to do.
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Sure, maybe the local theater that was built before WWII closed down because there's a better one within driving distance. Basically, small towns outsourced their "things to do" to bigger cities because those things no longer needed to be local. It would be nice to bring some of them back.
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And what's next? I suppose you'll want free coffee for the free coffee maker too? And free electricity to power it? And free sugar and substitutes while we're at it? Why not free milk and substitutes on top of that? And then I suppose you'll want a free fridge to keep those milk and substitutes refrigerated? And who's going to pay for the power to run that fridge? And you can fully expect people to start stuffing their lunch in that fridge too, leaving shit there for weeks until it turns bad and stink up th
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Aimed for funny, got marked as a troll. Some people need to recalibrate their sarcasm detector.
Re:Well, in the US... (Score:5, Funny)
Missing comma, should be:
coffee, joint, job, coffee, joint, job... then you don't care how shitty the food is, or the job...
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"It's the repetitive movement from job, coffee joint, job, coffee joint, job, shitty food joint, job, coffee joint, job, go home. Repeat."
The French have a shorter motto : "Métro, Boulot, Dodo"
(subway, work, sleep)
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In the US it's dealing with brain-dead transportation planning. In many US cities it is often necessary to take a car for a trip of under a 1000 feet. You sometimes can't even cross the street without getting in a car.
This is not the way US cities *evolved*. They actually evolved to be walkable and used to have efficient last-mile transit. Cities were *re-engineered* to prioritize traveling *through* neighborhoods over traveling *within* neighborhoods [youtube.com]. This has further been exacerbated by zoning codes t
Re: Well, in the US... (Score:2)
This study just demonstrated that people travelling less than a mile are only 25x the number of people traveling 5 miles. But if you go out 5 miles vs 1, you have about 25x the potential number of people. So, you would actually not expect most of the people who are there to have travelled less than a mile.
I spy with my science eye. (Score:5, Insightful)
Studying anonymized cell-phone data, researchers discovered what is known as an inverse square relation between the number of people in a given urban location and the distance they traveled to get there, as well as how frequently they made the trip.
One of the few times data-collection is beneficial. Aid in map-making for another.
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Studying anonymized cell-phone data, researchers discovered what is known as an inverse square relation between the number of people in a given urban location and the distance they traveled to get there, as well as how frequently they made the trip.
One of the few times data-collection is beneficial. Aid in map-making for another.
More likely, your regular information sources are heavily weighted towards complaining about things, rather than learning about things. If nobody is complaining about some collected data, you're less likely to hear about it.
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And it's called... (Score:2)
Sim City.
Or maybe it's step one in psychohistory.
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We definitely want to get these algorithms right before we retreat into the eco-bubble city-states of the post-warming future.
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I was thinking step one in Psychogeography, the Situationists had some cool ideas
How has lockdown affected the stats? (Score:2)
Just taking myself as an example, I have hardly ventured further than a twenty minute walk from home for a couple of years. Working from home means I don't need my four week bus pass any more.
Another interesting point on the stats is an observation by a work colleague from Spain, that he had to travel much further to work in Birmingham, UK, than he would have done in his native Seville.
When I was looking for work a number of years ago, I was obliged to apply for jobs with a travel time of up to 90 minutes.
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Had a coworker some years ago, who took the bus from the West side of the city, to work on the outer edge of the East side. Said trip took 2 hrs, each way. The same trip by car takes ~25 minutes.
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I am blessed with a good bus service in Birmingham. The 50 bus that goes to the city centre is I believe the most frequent running bus service in the UK. You don't look up the timetable. You just walk to the bus stop when you want to. A big contrast is my sister's place in rural Herefordshire. We got the bus into Hereford, to do a pub tour. I think the car journey would have been about 15 minutes, but the bus had to chunter around all the villages, so it took nearly an hour. But I was on holiday, so it was
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A large part of the problem is that public transport here in the US is an absolute joke if it even exists at all -- and the distances involved are non-trivial. And of course the moment you try to raise any funding for some social benefits, the Right starts screaming bloody murder.
Try to be clear, not clever, when explaining (Score:5, Insightful)
the number of people coming from two kilometers away five times per week will be the same as the number coming from five kilometers twice a week
There is nothing "inverse square" about that. That just makes the product of visitation frequency and distance a constant: 5*2=2*5. In other words, frequency is proportional to the inverse of distance: f=c*(1/d) <=> f*d=c, where c is a constant. Please choose examples which actually exemplify the key point you're making.
Re:Try to be clear, not clever, when explaining (Score:4, Interesting)
I was going to say the same thing, but then I noticed that there are *two* independent variables, not just one, and if both have the same inverse-square relationship to distance, wouldn't they just cancel eachother out?
Assuming an inverse square relationship to both distance *AND* the frequency of travel, the number of people coming in from 2km a given number of times per week could still be 6.25 times the number of people who travel 5km the same number times a week, and the number of people who come in twice per week could be 6.25 times the number who come in five times per week at a given distance.five times per week, for example, illustrating the inverse square relationship explicitly.
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You can't determine the mathematical relationship between variables by two datapoints because multiple families of curves can be drawn through those points.
Now f*d = c *does* work with the two points chosen in the SciAm article. But any equation in which f*d appears as a parameter could also work, for example the published equation from the actual paper (paraphrased):
rho(f,d) = mu/(f*d)^eta
where rho is the number of people visiting with a given distance and frequency, mu
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The two parameters only appear as their product in that formula, so one is proportional to the inverse of the other.
They actually have no relationship to each other in this context because they're *independent* variables. However if you fix the result (rho -- the number of people) then they do have an inversely proportional relationship.
So? (Score:1)
most car accidents happen close to home (Score:2)
my claim: "90% of the time people are driving 10 miles from their home, so statistically that's where they will most likely get into a fender bender".
Just in time for the Foundation series (Score:4, Insightful)
This is a bit like elementary psychohistory, remember to catch up on the Foundation novels before the Apple TV premiere on the 24th ;)
PS. Yes, I know the series will probably have little to do with the books as the books have almost zero "action". Still we can hope for something good...
Re: Just in time for the Foundation series (Score:1)
This is very old news (Score:5, Interesting)
I read about Reilly's theory of retail gravitation in the 70's, and have used it (combined with A*) for modelling my fantasy world's trading routes for years and years. Reilly's theory is an inverse square law too.
If they've refined, i particular, how to measure the draw of an area and the best way to measure distance (time, effort, etc.) then great, but this is not "super striking".
5*2=2*5 creates more questions than it answers (Score:1)
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It is not a mathematical law. (Score:1)
General public seem to have a perception "law" has higher level of trustworthiness than "theory". But highest level of trustworthiness are for theorems that are proved mathematically. Pythagoras theorem springs to one's mind immediately. But "The sum of two even numbers can never be an odd number" is the level of trust one can have in mathematical theorems.
Laws, on the other hand, are observations made nu
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Colloquially there is no or very little distinction between 'theory' and 'hypothesis'. And if you bring 'law' into the mix people get even more confused. Here I've observed in many works of fiction that there's a trope that if you 'break' a 'law of nature' that nature is going to punish you in some kind of way, making it analogous to the laws that human societies come up, which are not observed in nature but more or less an arbitrary construct by our respective societies.
Though some little add
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If we explain this to a journalist, we might see a
How anonymous is it when they know so much? (Score:2)
how many people were visiting, from how far and how frequently.
Even if all identifiers are replaced, they would still need to be related in order to determine frequency, duration and locations. Location, duration and frequency can result in identifying factors that can determine an individuals identity. I would say given enough data you could identify who the individual is by just 2 of the three.
Scale (Score:1)
One of the co-authors, Geoffrey West, wrote a book previously (Scale, 2017) in which he mentions this already. Not only travel patterns are similar, but a lot of things scale in a predictable way with the size of a city, like number of gas stations, criminality and number of innovations. And actually in a similar way that mammals scale.
Also, people tend to walk faster in bigger cities because they need to traverse a bigger distance and apparently want to always do this in the same amount of time.
incidentall
Obvious, but explains why more highways are bad (Score:2)
If you put in more highways, you get a small increase in speed, which quickly vanishes as more people move into the area that now has a quicker commute. No amount of more highways can remove traffic. Honestly, often the best way is to remove highways, thereby convincing people to not live so far away.
The honest truth is the way to decrease traffic is to remove highways and instead put in more vertical housing and mass transit. That is, sky scrapers in walking distance to work and light rail (or high q
Power laws used my market researchers for decades (Score:3)
Hari Seldon, is that you? (Score:1)
Pretty sure this is evidence Asimov could be as predictive as Jules Verne....
So, are they setting up the foundations? (Score:2)
I hope they factored in (Score:1)
Foundation equations 1.0 (Score:1)
Harry Seldon would be proud.