WEBVTT 00:00:01.725 --> 00:00:04.642 Hi. I'm here to talk about congestion, 00:00:04.642 --> 00:00:05.996 namely road congestion. 00:00:05.996 --> 00:00:08.257 Road congestion is a pervasive phenomenon. 00:00:08.257 --> 00:00:11.117 It exists in basically all of the cities all around the world, 00:00:11.117 --> 00:00:13.065 which is a little bit surprising when you think about it. 00:00:13.065 --> 00:00:16.028 I mean, think about how different cities are, actually. 00:00:16.028 --> 00:00:17.790 I mean, you have the typical European cities, 00:00:17.790 --> 00:00:20.782 with a dense urban core, good public transportation 00:00:20.782 --> 00:00:23.237 mostly, not a lot of road capacity. 00:00:23.237 --> 00:00:25.686 But then, on the other hand, you have the American cities. 00:00:25.686 --> 00:00:28.477 It's moving by itself, okay. 00:00:28.477 --> 00:00:31.483 Anyway, the American cities: 00:00:31.483 --> 00:00:34.411 lots of roads dispersed over large areas, 00:00:34.411 --> 00:00:35.870 almost no public transportation. 00:00:35.870 --> 00:00:38.080 And then you have the emerging world cities, 00:00:38.080 --> 00:00:39.606 with a mixed variety of vehicles, 00:00:39.606 --> 00:00:42.148 mixed land-use patterns, also rather dispersed 00:00:42.148 --> 00:00:44.747 but often with a very dense urban core. 00:00:44.747 --> 00:00:47.149 And traffic planners all around the world have tried 00:00:47.149 --> 00:00:50.803 lots of different measures: dense cities or dispersed cities, 00:00:50.803 --> 00:00:53.354 lots of roads or lots of public transport 00:00:53.354 --> 00:00:56.140 or lots of bike lanes or more information, 00:00:56.140 --> 00:00:59.934 or lots of different things, but nothing seems to work. NOTE Paragraph 00:00:59.934 --> 00:01:02.937 But all of these attempts have one thing in common. 00:01:02.937 --> 00:01:05.288 They're basically attempts at figuring out 00:01:05.288 --> 00:01:08.615 what people should do instead of rush hour car driving. 00:01:08.615 --> 00:01:11.727 They're essentially, to a point, attempts at planning 00:01:11.727 --> 00:01:14.929 what other people should do, planning their life for them. NOTE Paragraph 00:01:14.929 --> 00:01:17.381 Now, planning a complex social system 00:01:17.381 --> 00:01:20.456 is a very hard thing to do, and let me tell you a story. 00:01:20.456 --> 00:01:23.183 Back in 1989, when the Berlin Wall fell, 00:01:23.183 --> 00:01:25.805 an urban planner in London got a phone call 00:01:25.805 --> 00:01:28.355 from a colleague in Moscow saying, basically, 00:01:28.355 --> 00:01:30.873 "Hi, this is Vladimir. I'd like to know, 00:01:30.873 --> 00:01:33.895 who's in charge of London's bread supply?" NOTE Paragraph 00:01:33.895 --> 00:01:35.548 And the urban planner in London goes, 00:01:35.548 --> 00:01:37.518 "What do you mean, who's in charge of London's — 00:01:37.518 --> 00:01:38.789 I mean, no one is in charge." 00:01:38.789 --> 00:01:40.671 "Oh, but surely someone must be in charge. 00:01:40.671 --> 00:01:44.327 I mean, it's a very complicated system. Someone must control all of this." NOTE Paragraph 00:01:44.327 --> 00:01:47.433 "No. No. No one is in charge. 00:01:47.433 --> 00:01:50.034 I mean, it basically -- I haven't really thought of it. 00:01:50.034 --> 00:01:52.623 It basically organizes itself." NOTE Paragraph 00:01:52.623 --> 00:01:55.200 It organizes itself. 00:01:55.200 --> 00:01:58.043 That's an example of a complex social system 00:01:58.043 --> 00:02:00.771 which has the ability of self-organizing, 00:02:00.771 --> 00:02:03.359 and this is a very deep insight. 00:02:03.359 --> 00:02:06.672 When you try to solve really complex social problems, 00:02:06.672 --> 00:02:08.388 the right thing to do is most of the time 00:02:08.388 --> 00:02:09.979 to create the incentives. 00:02:09.979 --> 00:02:11.923 You don't plan the details, 00:02:11.923 --> 00:02:14.543 and people will figure out what to do, 00:02:14.543 --> 00:02:16.403 how to adapt to this new framework. NOTE Paragraph 00:02:16.403 --> 00:02:19.894 And let's now look at how we can use this insight 00:02:19.894 --> 00:02:21.530 to combat road congestion. NOTE Paragraph 00:02:21.530 --> 00:02:23.762 This is a map of Stockholm, my hometown. 00:02:23.762 --> 00:02:27.403 Now, Stockholm is a medium-sized city, roughly two million people, 00:02:27.403 --> 00:02:30.192 but Stockholm also has lots of water and lots of water 00:02:30.192 --> 00:02:33.469 means lots of bridges -- narrow bridges, old bridges -- 00:02:33.469 --> 00:02:36.504 which means lots of road congestion. 00:02:36.504 --> 00:02:40.144 And these red dots show the most congested parts, 00:02:40.144 --> 00:02:42.721 which are the bridges that lead into the inner city. 00:02:42.721 --> 00:02:45.247 And then someone came up with the idea that, 00:02:45.247 --> 00:02:47.084 apart from good public transport, 00:02:47.084 --> 00:02:49.685 apart from spending money on roads, 00:02:49.685 --> 00:02:53.900 let's try to charge drivers one or two euros at these bottlenecks. NOTE Paragraph 00:02:53.900 --> 00:02:56.824 Now, one or two euros, that isn't really a lot of money, 00:02:56.824 --> 00:02:59.481 I mean compared to parking charges and running costs, etc., 00:02:59.481 --> 00:03:02.199 so you would probably expect that car drivers 00:03:02.199 --> 00:03:04.637 wouldn't really react to this fairly small charge. 00:03:04.637 --> 00:03:05.937 You would be wrong. 00:03:05.937 --> 00:03:09.965 One or two euros was enough to make 20 percent of cars 00:03:09.965 --> 00:03:12.349 disappear from rush hours. 00:03:12.349 --> 00:03:15.900 Now, 20 percent, well, that's a fairly huge figure, you might think, 00:03:15.900 --> 00:03:18.107 but you've still got 80 percent left of the problem, right? 00:03:18.107 --> 00:03:19.976 Because you still have 80 percent of the traffic. 00:03:19.976 --> 00:03:23.243 Now, that's also wrong, because traffic happens to be 00:03:23.243 --> 00:03:25.935 a nonlinear phenomenon, meaning that 00:03:25.935 --> 00:03:29.076 once you reach above a certain capacity threshold 00:03:29.076 --> 00:03:32.244 then congestion starts to increase really, really rapidly. 00:03:32.244 --> 00:03:34.704 But fortunately, it also works the other way around. 00:03:34.704 --> 00:03:38.035 If you can reduce traffic even somewhat, then congestion 00:03:38.035 --> 00:03:41.664 will go down much faster than you might think. 00:03:41.664 --> 00:03:44.555 Now, congestion charges were introduced in Stockholm 00:03:44.555 --> 00:03:49.159 on January 3, 2006, and the first picture here is a picture 00:03:49.159 --> 00:03:53.142 of Stockholm, one of the typical streets, January 2. 00:03:53.142 --> 00:03:56.955 The first day with the congestion charges looked like this. 00:03:56.955 --> 00:03:59.875 This is what happens when you take away 00:03:59.875 --> 00:04:01.940 20 percent of the cars from the streets. 00:04:01.940 --> 00:04:04.650 You really reduce congestion quite substantially. NOTE Paragraph 00:04:04.650 --> 00:04:08.308 But, well, as I said, I mean, car drivers adapt, right? 00:04:08.308 --> 00:04:10.810 So after a while they would all come back because they 00:04:10.810 --> 00:04:12.758 have sort of gotten used to charges. 00:04:12.758 --> 00:04:16.434 Wrong again. It's now six and a half years ago 00:04:16.434 --> 00:04:18.417 since the congestion charges were introduced in Stockholm, 00:04:18.417 --> 00:04:22.406 and we basically have the same low traffic levels still. NOTE Paragraph 00:04:22.406 --> 00:04:24.677 But you see, there's an interesting gap here in the time series 00:04:24.677 --> 00:04:26.140 in 2007. 00:04:26.140 --> 00:04:28.529 Well, the thing is that, the congestion charges, 00:04:28.529 --> 00:04:31.625 they were introduced first as a trial, so they were introduced 00:04:31.625 --> 00:04:35.594 in January and then abolished again at the end of July, 00:04:35.594 --> 00:04:38.188 followed by a referendum, and then they were reintroduced 00:04:38.188 --> 00:04:42.388 again in 2007, which of course was a wonderful scientific opportunity. 00:04:42.388 --> 00:04:46.525 I mean, this was a really fun experiment to start with, 00:04:46.525 --> 00:04:48.306 and we actually got to do it twice. 00:04:48.306 --> 00:04:50.415 And personally, I would like to do this every once a year or so, 00:04:50.415 --> 00:04:51.903 but they won't let me do that. 00:04:51.903 --> 00:04:54.088 But it was fun anyway. NOTE Paragraph 00:04:54.088 --> 00:04:57.473 So, we followed up. What happened? 00:04:57.473 --> 00:05:01.339 This is the last day with the congestion charges, July 31, 00:05:01.339 --> 00:05:03.117 and you see the same street but now it's summer, 00:05:03.117 --> 00:05:04.861 and summer in Stockholm is a very nice 00:05:04.861 --> 00:05:07.111 and light time of the year, 00:05:07.111 --> 00:05:09.954 and the first day without the congestion charges 00:05:09.954 --> 00:05:11.321 looked like this. 00:05:11.321 --> 00:05:13.984 All the cars were back again, and you even have to admire 00:05:13.984 --> 00:05:16.894 the car drivers. They adapt so extremely quickly. 00:05:16.894 --> 00:05:19.141 The first day they all came back. 00:05:19.141 --> 00:05:24.491 And this effect hanged on. So 2007 figures looked like this. NOTE Paragraph 00:05:24.491 --> 00:05:26.822 Now these traffic figures are really exciting 00:05:26.822 --> 00:05:29.473 and a little bit surprising and very useful to know, 00:05:29.473 --> 00:05:32.232 but I would say that the most surprising slide here 00:05:32.232 --> 00:05:36.262 I'm going to show you today is not this one. It's this one. 00:05:36.262 --> 00:05:39.593 This shows public support for congestion pricing of Stockholm, 00:05:39.593 --> 00:05:42.262 and you see that when congestion pricing were introduced 00:05:42.262 --> 00:05:46.579 in the beginning of Spring 2006, people were fiercely against it. 00:05:46.579 --> 00:05:49.607 Seventy percent of the population didn't want this. 00:05:49.607 --> 00:05:51.255 But what happened when the congestion charges 00:05:51.255 --> 00:05:54.716 were there is not what you would expect, that people hated it more and more. 00:05:54.716 --> 00:05:57.869 No, on the contrary, they changed, up to a point 00:05:57.869 --> 00:06:01.570 where we now have 70 percent support for keeping the charges, 00:06:01.570 --> 00:06:03.411 meaning that -- I mean, let me repeat that: 00:06:03.411 --> 00:06:06.218 70 percent of the population in Stockholm 00:06:06.218 --> 00:06:10.211 want to keep a price for something that used to be free. NOTE Paragraph 00:06:10.211 --> 00:06:13.837 Okay. So why can that be? Why is that? 00:06:13.837 --> 00:06:16.837 Well, think about it this way. Who changed? 00:06:16.837 --> 00:06:19.463 I mean, the 20 percent of the car drivers that disappeared, 00:06:19.463 --> 00:06:21.408 surely they must be discontent in a way. 00:06:21.408 --> 00:06:23.742 And where did they go? If we can understand this, 00:06:23.742 --> 00:06:27.872 then maybe we can figure out how people can be so happy with this. 00:06:27.872 --> 00:06:30.274 Well, so we did this huge interview survey 00:06:30.274 --> 00:06:32.109 with lots of travel services, and tried to figure out 00:06:32.109 --> 00:06:33.864 who changed, and where did they go? 00:06:33.864 --> 00:06:38.278 And it turned out that they don't know themselves. (Laughter) 00:06:38.278 --> 00:06:43.126 For some reason, the car drivers are -- 00:06:43.126 --> 00:06:46.622 they are confident they actually drive the same way that they used to do. 00:06:46.622 --> 00:06:48.878 And why is that? It's because that travel patterns 00:06:48.878 --> 00:06:51.277 are much less stable than you might think. 00:06:51.277 --> 00:06:54.108 Each day, people make new decisions, and people change 00:06:54.108 --> 00:06:56.533 and the world changes around them, and each day 00:06:56.533 --> 00:06:59.786 all of these decisions are sort of nudged ever so slightly 00:06:59.786 --> 00:07:01.753 away from rush hour car driving 00:07:01.753 --> 00:07:04.337 in a way that people don't even notice. 00:07:04.337 --> 00:07:06.382 They're not even aware of this themselves. NOTE Paragraph 00:07:06.382 --> 00:07:09.183 And the other question, who changed their mind? 00:07:09.183 --> 00:07:11.149 Who changed their opinion, and why? 00:07:11.149 --> 00:07:13.675 So we did another interview survey, tried to figure out 00:07:13.675 --> 00:07:18.051 why people changed their mind, and what type of group changed their minds? 00:07:18.051 --> 00:07:20.944 And after analyzing the answers, it turned out that 00:07:20.944 --> 00:07:24.829 more than half of them believe that they haven't changed their minds. 00:07:24.829 --> 00:07:27.116 They're actually confident that they have 00:07:27.116 --> 00:07:29.805 liked congestion pricing all along. 00:07:29.805 --> 00:07:31.524 Which means that we are now in a position 00:07:31.524 --> 00:07:34.517 where we have reduced traffic across this toll cordon 00:07:34.517 --> 00:07:37.728 with 20 percent, and reduced congestion by enormous numbers, 00:07:37.728 --> 00:07:41.275 and people aren't even aware that they have changed, 00:07:41.275 --> 00:07:45.186 and they honestly believe that they have liked this all along. NOTE Paragraph 00:07:45.186 --> 00:07:48.660 This is the power of nudges when trying to solve 00:07:48.660 --> 00:07:51.292 complex social problems, and when you do that, 00:07:51.292 --> 00:07:54.922 you shouldn't try to tell people how to adapt. 00:07:54.922 --> 00:07:57.109 You should just nudge them in the right direction. 00:07:57.109 --> 00:07:58.831 And if you do it right, 00:07:58.831 --> 00:08:00.883 people will actually embrace the change, 00:08:00.883 --> 00:08:03.945 and if you do it right, people will actually even like it. 00:08:03.945 --> 00:08:07.270 Thank you. (Applause)