a line of vehicles that have stopped or are moving only very slowly, because of an accident or other problem on the road in front of them(路上因受阻而形成的)车辆长队,长龙
Yesterday there was a four-mile tailback on the main road into the city after a crash.昨天在一起交通事故以后,进城的干道上排起了4英里的长龙。