Over the course of many years, without making fuss about it, the authorities in New York disabled most of the control buttons that once operated pedestrian-crossing lights in the city. Computerized timers, they had decided, almost always worked better.

Initially, the buttons survived because of the cost of removing them. But it turned out that even inoperative buttons serve a purpose. Pedestrians who press a button are less likely to cross before the green man appears, says Tal Oron-Gilad of Ben-Gurion University of the Negev in Israel. Having studied behavior at crossings, she notes that people more readily obey a system which purports to heed their input.

Inoperative buttons produce placebo effects of this sort because people like an impression of control over systems they are using, says Eytan Adar, an expert on human-computer interaction at the University of Michigan, Ann Arbor. Adar notes that his students commonly design software with a clickable “save” button that has no role other than to reassure those users who are unaware that their keystrokes are saved automatically anyway.

However, Ralf Risser, head of factum, a Viennese institute that studies psychological factors in traffic systems, reckons that pedestrians’ awareness of their existence, and consequent resentment at the deception, now outweighs the benefits.

Something which happened in Lebanon supports that view. Crossing buttons introduced in Beirut between 2005 and 2009 proved a flop. Pedestrians wanted them to summon a “walk” signal immediately, rather than at the next appropriate phase in the traffic-light cycle, as is normal. The authorities therefore disabled them, putting walk signals on a preset schedule instead. Word spread that button-pressing had become pointless. The consequent frustration increased the amount of jaywalking.

Truth be told, though, the end may be nigh for all road-crossing buttons, placebo or real. At an increasing number of junctions, those waiting to cross can be detected, and even counted, using cameras or infrared and microwave detectors. Dynniq, a Dutch firm, recently equipped an intersection in Tilburg with a system that recognizes special apps on the smart phones of the elderly or disabled, and provides those people with 5 to 12 extra seconds to cross.

Words to Learn 相关词汇

【标榜】biāobǎng purport appear or claim to be or do something, especially falsely, profess

【失败】shībài flop a total failure

在很多年里，纽约市政部门逐步停用了该市控制人行横道信号灯的大部分按钮，但一直没怎么声张。他们认定，计算机控制的计时器更好用。

一开始，按钮不拆除是成本问题。后来却发现，即使无法控制信号灯的按钮也有用处。以色列本▪古里安大学的塔勒▪奥龙▪吉拉德表示，按下按钮的行人不太可能在绿灯亮起前就横穿马路。研究过人们在路口的行为后，她注意到大家更倾向于服从一个声称会听从他们指令的系统。

密歇根大学安娜堡分校的人机交互专家埃坦▪埃达表示，失效的按钮之所以会产生这种安慰剂效应，是因为人们喜欢对自己使用的系统有掌控感。

他指出，学生在设计软件时经常会加上一个可点击的“保存”按钮，但其实用户的输入都会自动保存，这个按钮仅仅是为了让对此不知情的用户放心而已。

但是，研究交通系统心理因素的维也纳FACTUM研究所的负责人拉尔

夫▪里瑟尔认为，行人意识到按钮无效进而感到被骗的怨怒，如今已让这种做法弊大于利。

黎巴嫩的情况可引为佐证。2005年至2009年间在贝鲁特引入的过街按钮最后被证明是失败的。行人希望按键后能立刻亮起“步行”信号，而不是像通常那样等待交通灯的周期性转换。因此市政部门停用了这些按钮，按预设的时间启动步行信号。过街按钮无用的消息传开，随之而来的懊恼导致更多人乱穿马路。

但事实上，无论是安慰剂还是真的过街按钮可能都离消亡不远了。越来越多的道路交汇处配备了摄像头或红外和微波探测器，可探测甚至统计等待过马路的行人。荷兰科技公司Dynniq近年在蒂尔堡市的一个十字路口安装了一套系统，能识别老年人或残疾人智能手机上的专门应用，为他们提供额外5到12秒的过马路时间。

(chinadaily.com.cn)