Hi. I'm here to talk about congestion,

嗨，我今天要談的是塞車

namely road congestion.

也就是所謂的交通擁塞

Road congestion is a pervasive phenomenon.

塞車非常普遍

It exists in basically all of the cities all around the world,

世界各地的城市都有這個問題

which is a little bit surprising when you think about it.

仔細想想其實令人驚訝

I mean, think about how different cities are, actually.

畢竟城市之間不同之處甚多

I mean, you have the typical European cities,

像典型的歐洲城市

with a dense urban core, good public transportation

都有稠密的都市中心，良好的公共交通

mostly, not a lot of road capacity.

但大部分道路狹小

But then, on the other hand, you have the American cities.

另一方面，我們看看美國城市

It's moving by itself, okay.

它自己動起來了，好

Anyway, the American cities:

言歸正傳，美國的城市裡

lots of roads dispersed over large areas,

許多道路散佈在大片土地上

almost no public transportation.

幾乎沒有公共交通工具

And then you have the emerging world cities,

再來是初嶄頭角的世界級城市

with a mixed variety of vehicles,

當中混雜各種交通工具

mixed land-use patterns, also rather dispersed

各種土地使用模式，而且相當分散

but often with a very dense urban core.

市中心卻多數人口稠密

And traffic planners all around the world have tried

世界各地的交通規劃人員

lots of different measures: dense cities or dispersed cities,

採用過不同措施：以密集或分散形式規劃城市

lots of roads or lots of public transport

建大量道路，或大力發展公共交通

or lots of bike lanes or more information,

規劃很多單車徑，或提供更多資訊

or lots of different things, but nothing seems to work.

措施不勝枚舉，但似乎都不得要領

But all of these attempts have one thing in common.

這一切努力都有一個共同點

They're basically attempts at figuring out

就是嘗試找出

what people should do instead of rush hour car driving.

人們避免在尖峰時間開車的方法

They're essentially, to a point, attempts at planning

基本上這些方法旨在影響人該做什麼

what other people should do, planning their life for them.

替別人規劃生活

Now, planning a complex social system

規劃一個複雜的社會系統相當困難

is a very hard thing to do, and let me tell you a story.

讓我給你說個故事

Back in 1989, when the Berlin Wall fell,

早在1989年，柏林圍牆倒下時

an urban planner in London got a phone call

一位倫敦的都市規劃師接到電話

from a colleague in Moscow saying, basically,

是莫斯科的同事打來的，他說

"Hi, this is Vladimir. I'd like to know,

“嗨，我是維拉迪摩，我想知道

who's in charge of London's bread supply?"

倫敦的麵包供應是誰管的？”

And the urban planner in London goes,

那位都市規劃師回應道

"What do you mean, who's in charge of London's —

“甚麼意思? 誰管理倫敦的...

I mean, no one is in charge."

沒人管啊。”

"Oh, but surely someone must be in charge.

“但總有個人管吧

I mean, it's a very complicated system. Someone must control all of this."

這個系統極其複雜，一定要有人管理運作。”

"No. No. No one is in charge.

“不，不，真沒人管

I mean, it basically -- I haven't really thought of it.

我意思是，我真的沒想過這問題

It basically organizes itself."

系統會自我管理吧。”

It organizes itself.

自我管理

That's an example of a complex social system

這例子說明複雜的社會系統

which has the ability of self-organizing,

擁有自我管理的能力

and this is a very deep insight.

這洞見發人深省

When you try to solve really complex social problems,

當你試圖解決非常複雜的社會問題

the right thing to do is most of the time

很多時候

to create the incentives.

正確的做法是製造誘因

You don't plan the details,

不需要規劃細節

and people will figure out what to do,

大家自會知道該做甚麼

how to adapt to this new framework.

如何適應這個新框架

And let's now look at how we can use this insight

讓我們現在看看如何應用這洞見

to combat road congestion.

來解決塞車問題

This is a map of Stockholm, my hometown.

這是我家鄉斯德哥爾摩的地圖

Now, Stockholm is a medium-sized city, roughly two million people,

中型城市，現時大約住了兩百萬人

but Stockholm also has lots of water and lots of water

但斯德哥爾摩除了水還是水

means lots of bridges -- narrow bridges, old bridges --

即是說城裡有很多橋，古老的，狹窄的

which means lots of road congestion.

亦即是說交通經常擁塞

And these red dots show the most congested parts,

這些紅點代表最擁塞的區域

which are the bridges that lead into the inner city.

也就是通往內城的橋

And then someone came up with the idea that,

後來有人想出解決方法

apart from good public transport,

不是改善公共運輸

apart from spending money on roads,

不是大費金錢興建道路

let's try to charge drivers one or two euros at these bottlenecks.

而是在瓶頸位置向司機徵收一兩歐元

Now, one or two euros, that isn't really a lot of money,

一兩二歐元不是甚麼大錢

I mean compared to parking charges and running costs, etc.,

相對於停車費和日常開支而言

so you would probably expect that car drivers

所以你可能以為司機們

wouldn't really react to this fairly small charge.

對這種小額收費無動於衷

You would be wrong.

你錯了

One or two euros was enough to make 20 percent of cars

一兩歐元足以令百分之二十的汽車

disappear from rush hours.

在尖峰時間從路上消失

Now, 20 percent, well, that's a fairly huge figure, you might think,

百份之二十，你或許覺得這是個大數字

but you've still got 80 percent left of the problem, right?

但仍有百份之八十的問題未解決，對嗎？

Because you still have 80 percent of the traffic.

因為仍然有百份之八十的汽車在路上

Now, that's also wrong, because traffic happens to be

這也是錯的

a nonlinear phenomenon, meaning that

因為交通問題不是綫性現象

once you reach above a certain capacity threshold

當你超過一個容量臨界點之後

then congestion starts to increase really, really rapidly.

交通擁塞會開始很快地惡化

But fortunately, it also works the other way around.

幸運的是，反之亦然

If you can reduce traffic even somewhat, then congestion

如果你可以稍為減少交通量

will go down much faster than you might think.

擁塞問題減輕的速度比你想像中更快

Now, congestion charges were introduced in Stockholm

道路收費於2006年1月3號在斯德哥爾摩實施

on January 3, 2006, and the first picture here is a picture

這裏第一張是斯德哥爾摩

of Stockholm, one of the typical streets, January 2.

一條典型街道的照片，在2號拍的

The first day with the congestion charges looked like this.

開始收費的第一天它變成這樣

This is what happens when you take away

這就是路上減少百分之二十的車輛以後

20 percent of the cars from the streets.

看起來的樣子

You really reduce congestion quite substantially.

實際上，塞車情況大為改善

But, well, as I said, I mean, car drivers adapt, right?

但正如我所說，汽車司機會適應的，對嗎？

So after a while they would all come back because they

所以不久之後，他們會回到路上

have sort of gotten used to charges.

因為他們已適應了收費

Wrong again. It's now six and a half years ago

又錯了，六年半前

since the congestion charges were introduced in Stockholm,

斯德哥爾摩開始徵收道路費

and we basically have the same low traffic levels still.

到了今天，路上的汽車流量依然偏低

But you see, there's an interesting gap here in the time series

但大家看，在時間序列上有個有趣的間縫

in 2007.

時為2007年

Well, the thing is that, the congestion charges,

實情是這樣的

they were introduced first as a trial, so they were introduced

道路收費最初引入時屬試驗性質

in January and then abolished again at the end of July,

故此在一月引入後，七月尾便被廢除

followed by a referendum, and then they were reintroduced

接着舉行全民投票，然後在2007年再次引入道路費

again in 2007, which of course was a wonderful scientific opportunity.

這當然是一次極好的研究機會

I mean, this was a really fun experiment to start with,

我意思是開始時它已是個有趣的實驗

and we actually got to do it twice.

而我們有機會兩次進行這實驗

And personally, I would like to do this every once a year or so,

對我來說，我希望大約一年進行一次

but they won't let me do that.

但他們不許我這樣做

But it was fun anyway.

無論如何這是有趣的實驗

So, we followed up. What happened?

我們跟進之後，有甚麼發現？

This is the last day with the congestion charges, July 31,

這是7月31日，徵收道路費的最後一天

and you see the same street but now it's summer,

你看到的是同一條街，而這正是夏季

and summer in Stockholm is a very nice

斯德哥爾摩的夏季

and light time of the year,

是年中非常天朗氣清的日子

and the first day without the congestion charges

取消道路收費的第一天

looked like this.

是這樣的

All the cars were back again, and you even have to admire

所有汽車都返回路上，你真的要佩服那些司機

the car drivers. They adapt so extremely quickly.

他們的反應真的很快

The first day they all came back.

他們第一天就回來了

And this effect hanged on. So 2007 figures looked like this.

情況持續下去，所以2007年的數據是這樣的

Now these traffic figures are really exciting

這些交通數據真的令人興奮

and a little bit surprising and very useful to know,

有點出人意表，但同時十分有用

but I would say that the most surprising slide here

但今天給大看的幻燈片中

I'm going to show you today is not this one. It's this one.

最令人驚奇的不是這張，而是這張

This shows public support for congestion pricing of Stockholm,

它顯示了市民支持在斯德哥爾摩實施道路收費

and you see that when congestion pricing were introduced

你看到當引入道路收費之時

in the beginning of Spring 2006, people were fiercely against it.

即2006年初春，人們激烈反對收費

Seventy percent of the population didn't want this.

百份之七十的市民反對收費

But what happened when the congestion charges

當道路收費實施後，出現的情況並不如你想像的那樣

were there is not what you would expect, that people hated it more and more.

人們會越來越憎惡它

No, on the contrary, they changed, up to a point

正好相反，他們改變了

where we now have 70 percent support for keeping the charges,

現時有百份之七十的市民支持繼續收費

meaning that -- I mean, let me repeat that:

我是說，讓我再說一次

70 percent of the population in Stockholm

斯德哥爾摩百份之七十的人口

want to keep a price for something that used to be free.

希望對一樣一向可免費使用的東西繼續收費

Okay. So why can that be? Why is that?

怎會這樣？有甚麼原因？

Well, think about it this way. Who changed?

試循這方向想。誰改變了？

I mean, the 20 percent of the car drivers that disappeared,

那百份之二十消失了的司機

surely they must be discontent in a way.

肯定會在某方面感到不滿

And where did they go? If we can understand this,

他們去了那裏？如果我們明白這點

then maybe we can figure out how people can be so happy with this.

或許便可以明白為何人們喜愛這措施

Well, so we did this huge interview survey

我們很多交通工具上

with lots of travel services, and tried to figure out

進行大型的訪問調查

who changed, and where did they go?

目的是要找出誰改變了，和這些人去了那裏？

And it turned out that they don't know themselves. (Laughter)

原來受訪者自己也不知道

For some reason, the car drivers are --

由於某些原因

they are confident they actually drive the same way that they used to do.

那些司機都認為他們按自己一貫的方式駕駛

And why is that? It's because that travel patterns

為甚麼會這樣？這是因為人們的駕駛路線

are much less stable than you might think.

並非如你想像那般穩定

Each day, people make new decisions, and people change

每一天，人會做新的決定，人會變

and the world changes around them, and each day

環繞他們的世界也在變

all of these decisions are sort of nudged ever so slightly

每一天這些決定會產生細微作用

away from rush hour car driving

促使他們避開繁忙時間駕車

in a way that people don't even notice.

人往往不會覺察這些作用

They're not even aware of this themselves.

他們自己甚至不知道自己已改變

And the other question, who changed their mind?

另一個問題是，誰改變了他們的心思？

Who changed their opinion, and why?

誰改變了他們的想法，和為甚麼？

So we did another interview survey, tried to figure out

我們為此做了另一個訪問調查

why people changed their mind, and what type of group changed their minds?

為了要了解人為何改變想法，和那些群組的人改變了想法？

And after analyzing the answers, it turned out that

分柝了數據之後，我們發現

more than half of them believe that they haven't changed their minds.

超過一半的人認為他們的想法沒有變

They're actually confident that they have

他們真的以為

liked congestion pricing all along.

他們一直都喜歡道路收費

Which means that we are now in a position

這即是說現在的情況是

where we have reduced traffic across this toll cordon

我們透過收費界線減少了百份二十交通流量

with 20 percent, and reduced congestion by enormous numbers,

同時大幅減少了塞車情況

and people aren't even aware that they have changed,

而人們甚至不為意他們已改變了

and they honestly believe that they have liked this all along.

並且他們誠實地相信他們一直都喜歡這個情況

This is the power of nudges when trying to solve

這就是我們解決複雜的社會問題時

complex social problems, and when you do that,

輕推所產生的力量，你那樣做的時候

you shouldn't try to tell people how to adapt.

你不應該試圖告訴人他們要如何適應

You should just nudge them in the right direction.

你只要輕輕把他們往對的方向推

And if you do it right,

如果你做得對

people will actually embrace the change,

人們會支持改變

and if you do it right, people will actually even like it.

並且如果你做得對，人們甚至會喜歡它

Thank you. (Applause)

謝謝大家。（拍掌）