美国交通工程师的工作对象包括:道路使用者(机动车及非机动车驾驶员,行人);车辆(各种机动车与非机动车);道路系统本身(路面、路口、信号、标志等)。实际上交通工程师应主要在道路系统本身发挥自己的作用。其次,他要和各种各样的道路使用者打交道。而他们在年龄、性别、职业等 US traffic engineers work for: road users (motor vehicles and non-motorized drivers, pedestrians); vehicles (all kinds of motor vehicles and non-motor vehicles); and the road system itself (roads, intersections, signals, signs, etc.). In fact, traffic engineers should play their part mainly in the road system itself. Second, he has to deal with a wide variety of road users. And they are in age, gender, occupation and so on