根据西方经济学,商品首先要具有物质性,即具有满足人类某种需求的某种物质特性,其次要具有可得性,即可用时间和可得地点,二者共同构成其使用价值。公路作为一种特殊商品,它的使用价值取决于消费者,也就是来往各地的司乘人员,因此公路质量成为左右其使用价值的关键因素, According to western economics, the commodity should first have materiality, that is, it has some kind of material characteristic that meets certain needs of mankind, and secondly it has availability, that is, the available time and the available place, and the two together constitute its use value. Highway as a special commodity, its value depends on the use of consumers, that is, to and from all over the crew, so highway quality has become a key factor in its use value,