为什么搜不到cmcc信号:我们走路的学问

行人的行走模式正逐渐成为新兴的研究领域。

The study of walking around the city is usually tied to safety. Research suggests that people who talk on the phone while cruising the sidewalk fail to process their surroundings as fully as those walking undistracted, as we previously reported. People who walk and talk cross the street with less time to spare than those who don't; they even have less time to spare than people who walk and solve a complex math problem. Other work has found that drunk walking can be potentially as dangerous as drunk driving, at least statistically speaking.

对城市中走路的研究通常与安全联系在一起。我们之前的研究发现，相比于不受干扰的时候，人们边走边讲电话时对周围环境的处理较为无效。而人们边交谈边过马路时，较少有空闲的时间来处理周围的环境；他们的空闲时间甚至少于边走边解决复杂的数学问题的人。其他的研究发现，醉酒后走路的潜在危害与酒醉驾驶相等，至少统计上如此。

But even silent, sober strolls are starting to catch the eyes of scientists. Last month the Economist published a great piece about the emerging science of typical pedestrian behavior — a field that combines elements of physics, engineering, statistics, and cognition to understand just how we'll take that next step:

但是安静的、清醒的走路也开始吸引研究者的注意。上个月，《经济学人》发布了一篇文章，讲的就是典型人行道行为科学研究的兴起。这是一个结合了物理、工程、统计和认知学的领域，试图弄清楚我们如何踏出下一步：

More than any other way of getting around—such as being crushed into a train or stuck in a traffic jam—walking appears to offer freedom of choice. Reality is more complicated. Whether stepping aside to avoid a collision, following the person in front through a crowd or navigating busy streets, pedestrians are autonomous yet constrained by others. They are both highly mobile and very predictable.

相比其他与人呆在一起的方式—比如挤进火车或堵在车流中，行走似乎提供给我们更多选择的自由。事实却更为复杂，不管是走向路边从而避开冲撞，在人潮中跟随前面的人，行人们是自主的，不过也被其他人所制约。他们虽然具有很高的移动性，其行为却高度可预测。

Much of the piece focuses on the research of Mehdi Moussaid, a crowd scientist at the Max Planck Institut for Human Development in Berlin. A great deal of Moussaid's work looks at how pedestrians respond to sidewalk traffic. When a person is walking straight toward another, for instance, a decision occurs whether to go right or left to avoid a collision. The decision has nothing to do with driving customs; inBritain, walkers avoid to the right despite driving on the left. Still people end up choosing the proper side through the some sort of implicit social understanding, Moussaid concluded in a 2009 study [PDF]:

许多此类的研究聚焦于Mehdi Moussaid，他是柏林的Max Planck人类发展研究所的群体学科学家。Moussaid对行人处理人行道上的交通状况做了大量研究。比如说，当一个人直走向另一个人的时候，就有一个问题—他往左走还是往右走来避免碰撞。Moussaid在2009年得出的研究结论是，人们最后会依据某种社会暗示来选择正确的边：

[W]e suggest that the left/right bias can be interpreted as a behavioural convention that emerges because the coordination during evading manoeuvres is enhanced when both pedestrians favour the same side (Bolay 1998; Helbing 1991). It is therefore advantageous for an individual to develop the same preference as the majority of people. Through a self-reinforcing process, most people would use the same strategy in the end. As both sides are equivalent in the beginning, the theory predicts that different preferences emerge in different regions of the world, as it is actually observed.

我们认为左/右偏见可以被视作一种行为传统，因为双方都选择同一个方向时，正确的选择被加强（Bolay 1998; Helbing 1991）。因此，与大多数人具备相同的偏好是有益于个体的。通过自我强化过程，大多数人最后都会选择同样的方法。而由于左右两边在一开始的时候并无区别，这一理论认为在不同的地区会出现不同的偏好，这也是为观察所证实的。

Not every society reacts to pedestrian congestion the same way. A recent comparison of Germans and Indians revealed that although people from both cultures walk "in a similar manner" when alone, their behavior varies greatly in the presence of others. As one might expect given the densities of their respective countries, Indians need less personal space than Germans do, according to the researchers. As a result, when Germans encountered traffic during a walking experiment, they decreased speed more rapidly than Indians did. "Surprisingly the more unordered behaviour of the Indians is more effective than the ordered behaviour of the Germans," the study concludes [PDF].

并不是每个社会都以同种方式处理人行道堵塞。最近一个对德国和印度人的研究发现，这两种文化中的人在独自行走的时候走路方式类似，但与他人一起时，他们的行为有很大的区别。也许是由于这两个国家不同的人口密度，研究发现印度人需要较少的人际距离。因此，当德国人在行走实验中遇到交通堵塞时，他们更快地放慢速度。该研究得出一个“令人吃惊”的结论—德国人较为有序的行为反而不及印度人无序的行为有效。

Moussaid has found that it's a natural tendency to clump together on the sidewalk. In a 2010 study published in PLoS One, Moussaid and colleagues reported that 70 percent of walkers travel in groups — a custom that slows down pedestrian flow by about 17 percent. That's because when pedestrian groups encounter space problems on the sidewalk they flex into V-shaped clusters that "do not have optimal 'aerodynamic' features" just so they can continue to talk, according to the researchers.

Moussaid发现一种在人行道上聚集在一起的自然趋势。在2010年发表于PloS One的一个研究中，他和同事们发现有70%的行人与别人一起行走，而这一习惯会大约降低人行道流动速度的17%。因为当一个群体在人行道上碰到状况时，他们弯曲成V型从而能够继续行走，但是这种形态并不是空间动力学的最优。

Other scientists are more interested in the course of an urban journey. In the January issue of Transportation Research Part F, Greek engineer Eleonora Papadimitriou presents a model of typical street-crossing behavior by city pedestrians. Papadimitriou found that people tend to cross major streets either at the beginning or the end of long trips through the city. People who walk fast tend to postpone crossings as long as possible; they're also more likely to cross in the middle of the block. Mid-block crossing rises in frequency with the length of a trip, one-way roads, and curbside parking. As the number of traffic lanes increases, however, we become more likely to cross at an official juncture. 

其他的科学家更为关注郊区旅行的过程。一月份的Transporation Research Part E杂志中，希腊的工程学家Eleonora Papadimitriou提出了一个典型的城间旅行者过交叉路的行为模式。他发现人们在长途旅程的开始和最后阶段，更倾向于穿过城市中的主要街道。走得快的人，更倾向于尽可能的推迟过交叉路口，更可能横穿街区中间。横跨街区的频率随旅程的长度、单向路和路边停车的数量增加而增长。随着行车线的数目增加，人们反而更可能交叉在同一路口。

In the end the study of basic pedestrian behavior still comes back to public safety. Understanding how we walk can increase the safety of crowd movements: it can help architects design more effective building exits and help event planners prepare for mass gatherings like the Olympics or the World Cup. While Moussaid began his work from a physicist's perspective, he has since adjusted his views to include cognitive factors of pedestrian behavior [PDF]; as a result, he now suspects that changes to the visual field, such as lighting systems, could help direct people through crowds in an emergency. Papadimitriou, meanwhile, believes that a better understanding of urban crossing behavior will ultimately help city road networks — too often "oriented towards motorists' needs" — adjust to the needs of pedestrians.

最后，这一领域的研究仍然要回到关于公共交通的问题。理解我们如何走路，能够提高在群体中行动的安全性，帮助设计师更有效地设计出口，帮助活动策划人员更好地准备大规模的人群聚集（如奥林匹克和世界杯）。当Moussaid以物理学家的角度开展他的研究时，他开始将行人行为的认知因素纳入研究中；而现在，他开始考虑从可视化的角度（如照明系统），来改善群体中产生突发状况时人们的反应能力。而Papadimitriou认为，更好的理解郊区的马路行为，能够最终帮助城市道路网络的建设更加以行人为导向，而不是现在的以机动车司机为导向。