Most highways in the U.S. are wide enough for three or four cars to travel side-by-side. Many areas require that slow drivers drive in the far-right lane. Faster moving traffic operates in the middle lanes. The fastest cars drive on the far-left side -- also called the fast lane.________________________美国大部分公路宽度足够三到四辆车并列通行.许多地区要求开得慢的司机在最右侧车道行驶,更快的车流在中间车道行驶,开得最快的司机在最左边车道也就是快车道行驶._____________________________