Hej. Jeg er her for at snakke om propper, nemlig trafikpropper. Trafikpropper er et gennemgående problem. Det findes i alle byer over hele verden, hvilket er lidt overraskende når man tænker over det. Jeg mener, tænk på hvor forskellige byer faktisk er. Jeg mener, vi har de typiske europæiske byer, med en tæt urban kerne, god offentlig transport ikke stor vejkapacitet. Men på den anden side har vi de amerikanske byer. Den går af sig selv, okay. Men de amerikanske byer: En masse veje spredt over store arealer, næsten ingen offentlig transport. Og så har vi byerne i udviklingslandene, med et blandet mix af køretøjer, blandet udnyttelse af land, også ret spredt men ofte med en meget tæt urban kerne. Og trafikplanlæggere over hele verden har prøvet en masse virkemidler: tætte byer eller spredte byer, masser af vej, masser af offentlig transport, masser af cykelstier eller mere information, og en masse andre ting, men intet ser ud til at virke.
Hi. I'm here to talk about congestion, namely road congestion. Road congestion is a pervasive phenomenon. It exists in basically all of the cities all around the world, which is a little bit surprising when you think about it. I mean, think about how different cities are, actually. I mean, you have the typical European cities, with a dense urban core, good public transportation mostly, not a lot of road capacity. But then, on the other hand, you have the American cities. It's moving by itself, okay. Anyway, the American cities: lots of roads dispersed over large areas, almost no public transportation. And then you have the emerging world cities, with a mixed variety of vehicles, mixed land-use patterns, also rather dispersed but often with a very dense urban core. And traffic planners all around the world have tried lots of different measures: dense cities or dispersed cities, lots of roads or lots of public transport or lots of bike lanes or more information, or lots of different things, but nothing seems to work.
Men alle disse forsøg har en ting til fælles. De er forsøg på at finde ud af hvad folk skal gøre istedet for myldretidskørsel. De er i grunden, til et vist punkt, forsøg på at planlægge hvad andre skal gøre, at planlægge livet for dem.
But all of these attempts have one thing in common. They're basically attempts at figuring out what people should do instead of rush hour car driving. They're essentially, to a point, attempts at planning what other people should do, planning their life for them.
At planlægge et komplekst socialt system er meget svært at gøre og lad mig fortælle en histore. Tilbage i 1989 da Berlinmuren faldt fik en byplanlægger i London en telefonopringning fra en kollega i Moskva som sagde "Hej, det er Vladimir. Jeg vil gerne vide hvem der styrer Londons brødforsyning?"
Now, planning a complex social system is a very hard thing to do, and let me tell you a story. Back in 1989, when the Berlin Wall fell, an urban planner in London got a phone call from a colleague in Moscow saying, basically, "Hi, this is Vladimir. I'd like to know, who's in charge of London's bread supply?"
Og byplanlæggeren i London siger "Hvad mener du med hvem der styrer, jeg mener, der er ingen der styrer." "Jo, men der må da være nogen der styrer. Jeg mener, det er et meget kompliceret system. Nogen må kontrollere alt dette."
And the urban planner in London goes, "What do you mean, who's in charge of London's — I mean, no one is in charge." "Oh, but surely someone must be in charge. I mean, it's a very complicated system. Someone must control all of this."
"Nej, nej, ingen bestemmer. Jeg mener, jeg har aldrig rigtig tænkt over det. Det organiserer sig selv."
"No. No. No one is in charge. I mean, it basically -- I haven't really thought of it. It basically organizes itself."
Det organiserer sig selv. Det er et eksempel på et komplekst socialt system som har evnen til selvorganisering, og det er en dyb indsigt. Når du prøver at løse rigtig komplekse sociale problemer, så er det rette at gøre oftest at skabe incitamenter. Du planlægger ikke detaljerne, og folk finder ud af hvad de skal gøre, for at tilpasse sig de nye betingelser.
It organizes itself. That's an example of a complex social system which has the ability of self-organizing, and this is a very deep insight. When you try to solve really complex social problems, the right thing to do is most of the time to create the incentives. You don't plan the details, and people will figure out what to do, how to adapt to this new framework.
Og lad os nu se hvordan vi kan bruge den indsigt til at bekæmpe trafikpropper.
And let's now look at how we can use this insight to combat road congestion.
Dette er et kort over min hjemby Stockholm. Stockholm er en mellemstor by med ca. 2 millioner mennesker, men Stockholm er også masser af vand og det betyder masser af broer - smalle broer, gamle broer - hvilket giver masser af trafikpropper. Og de røde prikker viser områder med mest trængsel, som er broerne ind til den indre by. Og så fandt nogen på at, parallelt med god offentlig transport, parallelt med investeringer i veje, så prøver vi at at afkræve et par euro af bilisterne ved disse flaskehalse.
This is a map of Stockholm, my hometown. Now, Stockholm is a medium-sized city, roughly two million people, but Stockholm also has lots of water and lots of water means lots of bridges -- narrow bridges, old bridges -- which means lots of road congestion. And these red dots show the most congested parts, which are the bridges that lead into the inner city. And then someone came up with the idea that, apart from good public transport, apart from spending money on roads, let's try to charge drivers one or two euros at these bottlenecks.
Nu er et par euro ikke så mange penge, sammenlignet med parkeringsafgifter og driftsudgifter så man skulle tro at bilisterne ikke ville reagere på en så lille afgift. Man måtte tro om igen. Et par euro var nok til at 20 procent af bilerne forsvandt fra myldretiden. Du ville måske sige at 20% er et stort tal, men vi har stadig 80% af problemet, ikke? For vi har stadig 80% af trafikken. Men det er også forkert, for trafikken er et ikke-lineært fænomen, som betyder at så snart man krydser en bestemt kapacitetsgrænse begynder trafikproppen at øge meget hurtigt. Men heldigvis gælder det modsatte også. Hvis du reducerer trafikken en smule, vil trafikpropper forsvinde hurtigere end du tror. Trængselsafgifter blev indført i Stockholm den 3. januar 2006 og det første billede er en typisk vej i Stockholm den 2. januar. Den første dag med trængselsafgift så sådan ud. Det er hvad der sker når du fjerner 20% af bilerne fra gaderne. Du reducerer virkelig trængselen.
Now, one or two euros, that isn't really a lot of money, I mean compared to parking charges and running costs, etc., so you would probably expect that car drivers wouldn't really react to this fairly small charge. You would be wrong. One or two euros was enough to make 20 percent of cars disappear from rush hours. Now, 20 percent, well, that's a fairly huge figure, you might think, but you've still got 80 percent left of the problem, right? Because you still have 80 percent of the traffic. Now, that's also wrong, because traffic happens to be a nonlinear phenomenon, meaning that once you reach above a certain capacity threshold then congestion starts to increase really, really rapidly. But fortunately, it also works the other way around. If you can reduce traffic even somewhat, then congestion will go down much faster than you might think. Now, congestion charges were introduced in Stockholm on January 3, 2006, and the first picture here is a picture of Stockholm, one of the typical streets, January 2. The first day with the congestion charges looked like this. This is what happens when you take away 20 percent of the cars from the streets. You really reduce congestion quite substantially.
Men, som jeg sagde, jeg mener, bilister tilpasser sig, ikke? Så efter et stykke tid ville de komme tilbage fordi de ville vænne sig til afgifterne. Forkert igen. Det er nu seks og et halvt år siden trængselsafgiften blev indført i Stockholm, og vi har stort set det samme lave trafikniveau.
But, well, as I said, I mean, car drivers adapt, right? So after a while they would all come back because they have sort of gotten used to charges. Wrong again. It's now six and a half years ago since the congestion charges were introduced in Stockholm, and we basically have the same low traffic levels still.
Men du ser at der er et interessant hul i tidsserierne i 2007. Sagen er at trængselsafgiften blev indført først som en forsøgsordning i januar og så afskaffet igen sidst i juli, fulgt af en folkeafstemning, og så genindført igen i 2007, og det var selvfølgelig en stor mulighed for forskning. Jeg mener, det var et sjovt eksperiment til at begynde med, og så fik vi lov til at gøre det to gange. Og personligt gjorde jeg det gerne en gang om året, men det ville de ikke lade mig gøre. Men det var sjovt alligevel.
But you see, there's an interesting gap here in the time series in 2007. Well, the thing is that, the congestion charges, they were introduced first as a trial, so they were introduced in January and then abolished again at the end of July, followed by a referendum, and then they were reintroduced again in 2007, which of course was a wonderful scientific opportunity. I mean, this was a really fun experiment to start with, and we actually got to do it twice. And personally, I would like to do this every once a year or so, but they won't let me do that. But it was fun anyway.
Så vi fulgte det op. Hvad skete? Dette er sidste dag med trængselsafgifter, 31. juli, og vi ser samme vej men om sommeren, og sommer i Stockholm er en skøn og let tid på året, og den første dag uden trængselsafgifter så sådan ud. Alle bilerne var tilbage igen og man må beundre bilisterne. De tilpasser sig ekstremt hurtigt. På den første dag var de alle tilbage. Og den effekt varede ved. Så 2007 tal så sådan ud.
So, we followed up. What happened? This is the last day with the congestion charges, July 31, and you see the same street but now it's summer, and summer in Stockholm is a very nice and light time of the year, and the first day without the congestion charges looked like this. All the cars were back again, and you even have to admire the car drivers. They adapt so extremely quickly. The first day they all came back. And this effect hanged on. So 2007 figures looked like this.
Disse trafiktal er meget spændende og lidt overraskende og meget nyttige at vide, men den mest overraskende slide jeg vil vise idag er ikke denne, men denne. Den viser opbakningen til trængselsafgift i Stockholm, og man ser at da afgiften blev indført i begyndelsen af 2006 var folk stærkt imod den. 70% af befolkningen ville ikke have det. Men det der skete da trængselsafgiften kom er ikke hvad man ville forvente, at folk hadede den mere og mere. Nej, tværtimod, de skiftede mening så langt at vi nu har 70% støtte til at beholde afgiften, som betyder, lad mig gentage at: 70% af befolkningen i Stockholm ønsker at beholde en pris for noget som før var gratis.
Now these traffic figures are really exciting and a little bit surprising and very useful to know, but I would say that the most surprising slide here I'm going to show you today is not this one. It's this one. This shows public support for congestion pricing of Stockholm, and you see that when congestion pricing were introduced in the beginning of Spring 2006, people were fiercely against it. Seventy percent of the population didn't want this. But what happened when the congestion charges were there is not what you would expect, that people hated it more and more. No, on the contrary, they changed, up to a point where we now have 70 percent support for keeping the charges, meaning that -- I mean, let me repeat that: 70 percent of the population in Stockholm want to keep a price for something that used to be free.
Okay. Så hvordan kan det være? Hvorfor det? Tænk på det sådan: Hvem skiftede mening? Jeg mener, de 20% af bilisterne som forsvandt, de må da være utilfredse. Og hvor forsvandt de hen? Hvis vi kan forstå dette kan vi måske forstå hvordan folk kan være så tilfredse. Så vi foretog en stor spørgeundersøgelse med mange rejsetilbud og prøvede at finde hvem der skiftede mening og hvor forsvandt de hen? Og det viser sig at de ikke selv ved det. (Latter) Af en eller anden grund er bilisterne overbevist om at de kører som de altid har gjort. Og hvordan kan det være? Det er fordi rejsemønstrene er meget mindre stabile end du tror. Hver dag tager folk nye beslutninger og de forandrer sig og verden omkring dem forandrer sig, og hver dag bliver alle disse valg skubbet en smule væk fra myldretidskørsel på en måde folk ikke mærker selv. De er ikke engang klar over det.
Okay. So why can that be? Why is that? Well, think about it this way. Who changed? I mean, the 20 percent of the car drivers that disappeared, surely they must be discontent in a way. And where did they go? If we can understand this, then maybe we can figure out how people can be so happy with this. Well, so we did this huge interview survey with lots of travel services, and tried to figure out who changed, and where did they go? And it turned out that they don't know themselves. (Laughter) For some reason, the car drivers are -- they are confident they actually drive the same way that they used to do. And why is that? It's because that travel patterns are much less stable than you might think. Each day, people make new decisions, and people change and the world changes around them, and each day all of these decisions are sort of nudged ever so slightly away from rush hour car driving in a way that people don't even notice. They're not even aware of this themselves.
Og det andet spørgsmål, hvem skiftede mening? Hvem ændrede holdning og hvorfor? Vi gjorde en anden spørgeundersøgelse for at finde hvorfor folk skiftede mening og hvilke grupper skiftede mening? Og efter at have analyseret svarene viste det sig at mere end halvdelen tror de ikke har skiftet mening. De er faktisk overbevist om at de altid har været glad for trængselsafgiften. Det betyder at vi nu har reduceret trafikken gennem bommene med 20% og reduceret trafikpropperne enormt, og folk er ikke klar over at de har ændret mening og tror at de har kunnet lide det hele tiden.
And the other question, who changed their mind? Who changed their opinion, and why? So we did another interview survey, tried to figure out why people changed their mind, and what type of group changed their minds? And after analyzing the answers, it turned out that more than half of them believe that they haven't changed their minds. They're actually confident that they have liked congestion pricing all along. Which means that we are now in a position where we have reduced traffic across this toll cordon with 20 percent, and reduced congestion by enormous numbers, and people aren't even aware that they have changed, and they honestly believe that they have liked this all along.
Dette er styrken i de små skub når man vil løse komplekse sociale problemer, og når du gør det, burde du ikke fortælle folk hvordan de skal tilpasse sig. Du burde kun skubbe dem lidt i rigtig retning. Og gør du det rigtigt, vil folk faktisk omfavne ændringen, og hvis gjort rigtigt vil folk elske det. Tak. (Applaus)
This is the power of nudges when trying to solve complex social problems, and when you do that, you shouldn't try to tell people how to adapt. You should just nudge them in the right direction. And if you do it right, people will actually embrace the change, and if you do it right, people will actually even like it. Thank you. (Applause)