联合国环境保护机构最近的调查报告指出,无论是工业化国家还是发展中国家,在制定其交通政策时,无不受到以下因素的制约,即人口、环境、能源和道路。从总体环境以及长远角度来考虑,越来越多的国家认为,应将长远发展方向定位在公众交通上,“公交优先”应成为本国实施城市交通改革的政策基础。调查表明,自20世纪90年代以来,世界上许多国家的财政预算对发展公共交通均持优先支持的政策。1991～2000年,北美、欧洲和日本在公共交通方面的投资 According to a recent survey by the United Nations Environmental Protection Agency, both industrialized and developing countries are constraining their population, environment, energy and roads in formulating their transport policies. Considering the overall environment and the long-term perspective, more and more countries think that the long-term development orientation should be positioned on public transport and “public transport priority” should become the policy basis for implementing urban transport reform in their own countries. Surveys show that since the 1990s, the fiscal budgets of many countries in the world have given priority to the development of public transport. 1991-2000, North America, Europe and Japan in public transport investment