我作为美国空军人员分遣部队的一员驻扎在英国皇家空军某某地，那里有一条狭窄的马路蜿蜒穿过拥挤的居民区。因为多次出现汽车撞伤行人一类不甚严重的车祸，美国空军司令员决定将车速限制在每小时三英里。

　　新的车速限制公布后不久，一名骑警中士因一名吉普车司机开车时速达五英里而给他开了一张超速传票。

　　我很想知道骑警是怎样如此精确地知道那辆吉普车的速度的。“我遛达着要在邮局关门之前到达那里，”他解释道：“当我超过吉普车时，我注意到计速器指向了每小时五英里。”

Speed Limit

　　The British RAF base where I was stationed as part of a contingent of USAF personnel had one narrow road winding through the crowded residential area. After a rash of minor vehicle pedestrian accidents， the USAF commander decided to reduce the speed limit to three m.p.h.

　　Shortly after the new limit was posted， an MP sergeant issued a speeding citation to a jeep driver for going five m.p.h. I was curious to know how the MP had determined the jeep’s speed so exactly. “I was jogging to get to the PX before it closed，” he explained， “and as I passed the jeep， I noticed that the speedometer read five m.p.h.”