文档介绍：1 Urban transportation Planning An urban transportation system is ponent of an urban area's social , econom ic, and physical structure. Not only does the design and performance ofa transportation sys tem provide opportunities for mobility ,but over the long term , it influences patterns of growth and the level of economic activity through the accessibility it provides to land. Planning for the development or maintenance of the urban transportation system is thus an important activity , both for promoting the efficient movement of people and goods in an ur ban area and for maintaining the strong supportive role that transportation can play in attaining munity objectives. There are several basic concepts about an urban transportation system that should be kept in mind. Most important , a transportation system in an urban area is defined as consisting of the facilities and services that allow travel throughout the region , providing opportuni ties for:(I)mobility to residents of an urban area and movement of goods and (2) accessibil ity to land .Given this definition , an urban transportation system can be further character ized by three ponents: the spatial configuration that permits travel from one location to another; the transportation technologies that provide the means of moving over these distances; and the institutional framework that provides for the planning, construction, operation, and maintenance of system facilities. The Spatial Configuration ofa Transportation System One way to describe the spatial dimension of an urban transportation system is to consider the characteristics of individual trips from anor igin toa destination. For example, a trip can consist of several types of movement undertaken to achieve different objectives. Travelers leaving home might use a local bus system to reach a suburban subway station(a trip collection process) , proceed through the station to the subway platform (a transfer process) , ride the subway toa downtown station (