“Phantom” Traffic Jams Are Real—and Scientists Know How to Stop Them[A] Traffic jams are a common problem of most big cities, either in developed or in developing countries, but one kind of traffic jams in particular can be especially frustrating. These are generally known as “phantom” traffic jams, in which dense traffic crawls to a halt for no apparent reason at all.[B] “When caught in such a traffic jam, it is common for drivers to assume that there must be an accident, or construction or something,” said Massachusetts Institute of Technology (MIT) computer science professor Berthold Horn. “And then you drive and drive and drive … and there isn’t anything there.”[C] The exact cause of these phantom traffic jams has long remained a mystery. But now, new research has found the cause and researchers may have come up with a solution for this frustrating traffic pattern: maintaining equal spacing between cars on the road, rather than driving so closely behind another vehicle that a collision (碰撞) is likely if that vehicle brakes suddenly.[D] Horn said phantom traffic jams are an emergent property of the flow of vehicles down a highway. A phantom jam begins when a car in dense traffic slows down even slightly, which causes the car behind that vehicle to slow even more—and the slowing action spreads backward through the lane of traffic like a wave, getting worse the farther it spreads. Eventually, the cars far behind are forced to stop completely or risk hitting the slower vehicles ahead—and so the traffic grinds to a halt over nothing, Horn said.The age-long mystery has now been resolved as to how phantom traffic jams are caused. ____12____
“Phantom” Traffic Jams Are Real—and Scientists Know How to Stop Them [A] Traffic jams are a common problem of most big cities, either in developed or in developing countries, but one kind of traffic jams in particular can be especially frustrating. These are generally known as “phantom” traffic jams, in which dense traffic crawls to a halt for no apparent reason at all. [B] “When caught in such a traffic jam, it is common for drivers to assume that there must be an accident, or construction or something,” said Massachusetts Institute of Technology (MIT) computer science professor Berthold Horn. “And then you drive and drive and drive … and there isn’t anything there.” [C] The exact cause of these phantom traffic jams has long remained a mystery. But now, new research has found the cause and researchers may have come up with a solution for this frustrating traffic pattern: maintaining equal spacing between cars on the road, rather than driving so closely behind another vehicle that a collision (碰撞) is likely if that vehicle brakes suddenly. [D] Horn said phantom traffic jams are an emergent property of the flow of vehicles down a highway. A phantom jam begins when a car in dense traffic slows down even slightly, which causes the car behind that vehicle to slow even more—and the slowing action spreads backward through the lane of traffic like a wave, getting worse the farther it spreads. Eventually, the cars far behind are forced to stop completely or risk hitting the slower vehicles ahead—and so the traffic grinds to a halt over nothing, Horn said. The age-long mystery has now been resolved as to how phantom traffic jams are caused. ____12____
题目解答
答案
解析
本题考查对文章中关于“phantom traffic jams”成因相关信息的理解。解题思路是仔细阅读文章中与“phantom traffic jams”成因相关的段落，提取关键信息，然后判断题目表述是否与文章内容相符。
- 首先，在文章C段中，明确提到“new research has found the cause and researchers may have come up with a solution for this frustrating traffic pattern”，这表明新的研究已经找到了“phantom traffic jams”的成因，并且研究人员可能已经提出了解决方案。
- 接着，D段进一步解释了“phantom traffic jams”的形成机制：“A phantom jam begins when a car in dense traffic slows down even slightly, which causes the car behind that vehicle to slow even more—and the slowing action spreads backward through the lane of traffic like a wave, getting worse the farther it spreads. Eventually, the cars far behind are forced to stop completely or risk hitting the slower vehicles ahead—and so the traffic grinds to a halt over nothing”。即当一辆车在密集车流中稍微减速时，后面的车会减速更多，这种减速像波浪一样向后传播，传播得越远情况越糟，最终导致后面的车完全停止，交通陷入停滞。
- 综合C段和D段的内容，可以确定“phantom traffic jams”的成因已经被揭示，且有了解决方法，题目表述与文章内容相符。