人口城市化是当今各国城市发展的客观规律。目前世界上有近300个人口超过百万的大城市,到本世纪末,将增加到400多个。随着城市人口密度的增长,原有市区势必向城市边缘地区急剧扩展。住宅区愈加远离商业区和工作单位,引起更多的人口流动。城市交通则应能最大限度地满足这种交 Population urbanization is an objective law of urban development in all countries. At present, there are nearly 300 large cities with a population of over one million in the world and will increase to more than 400 by the end of this century. With the growth of urban population density, the original urban area is bound to expand rapidly to the fringe of the city. The more remote residential areas are from business districts and work units, causing more population movements. City traffic should be able to meet the best to pay