Believe it or not, optical illusion（错觉）can cut highway crashes.
Japan is a case in point. It has reduced automobile crashes on some roads by nearly 75 percent using a simple optical illusion. Bent stripes, called chevrons（人字形）, painted on the roads make drivers think that they are driving faster than they really are, and thus drivers slow down.
Now the American Automobile Association Foundation for Traffic Safety in Washington D.C. is planning to repeat Japan's success. Starting next year, the foundation will paint chevrons and other patterns of stripes on selected roads around the country to test how well the patterns reduce highway crashes.
Excessive speed plays a major role in as much as one fifth of all fatal traffic accidents, according to the foundation. To help reduce those accidents, the foundation will conduct its tests in areas where speed-related hazards are the greatest—curves, exit slopes, traffic circles, and bridges.
Some studies suggest that straight, horizontal bars painted across roads can initially cut the average speed of drivers in half. However, traffic often returns to full speed within months as drivers become used to seeing the painted bars.
Chevrons, scientists say, not only give drivers the impression that they are driving faster than they really are, but also make a lane appear to be narrower. The result is a longer lasting reduction in highway speed and the number of traffic accidents.
The passage mainly discusses ________.
通读全文，我们可以知道，本文主要讲了“为了控制车速，减少交通事故，美国决定在公路上画人字形标志。”故选A。
On roads painted with chevrons, drivers tend to feel that ________.
第一段提到“But stripes, called chevrons, painted on the roads make drivers think that they are driving faster than they really are, and thus drivers slow down”，由此可知司机会感到应该减速。故选C。
The advantage of chevrons over straight, horizontal bars is that the former ________.
根据最后两段对比可知，人字形线比直线、平等线对控制车速 有更长久的影响。故选C。
The American Automobile Association Foundation for Traffic Safety plans to ________.
第三段提到“is planning to repeat Japan's success”，由此可知美 国计划复制日本成功的范本。故选A。
What does the author say about straight, horizontal bars painted across roads?
根据第五段“However, traffic often returns to full speed within months as drivers become used to seeing the painted bars”可知，当司机 习惯了路上的条形图后，不出几个月交通又恢复快速。故选B。