On a typical weekday evening in downtown Washington recently, motorists inched along in stop-and-go traffic, pedestrians braced themselves against a blustery wind, trying to make their way home.

• 最近某个平常的工作日夜晚，华盛顿市中心的车辆艰难地往前挪动，行人们努力在大风中站稳，费劲地往家中走去。