EVALUATION OF ROAD AND TRANSIT SYSTEM REQUIREMENTS FOR ALTERNATIVE URBAN FORMS

Research was performed for the purpose of evaluating the road and transit system requirements of a range of cities that have different density and spatial patterns and thereby assessing the effects of varying urban forms on transportation investment and service measures. The assessment is conducted in the context of a proposed policy evaluation framework that uses the end-state transportation and land-use plan for policy guidance and the time stream of benefits and costs as the object of evalaution. For the analysis of the transportation implications of a number of urban forms, a two-mode network generation model is developed and applied to six hypothetical city types of 2 million population. The comparison of the transportation requirements for these urban forms indicates a range of transit use among the city types of from 8 to 24 percent and wide differences in the need for high-capacity service routes. In terms of person hours of travel and mean trip length, the multicentered city in particular and the centrally oriented cities in general have the lowest requirements. These conclusions have important implications for the use of horizon-year transportation and land-use plans within the proposed framework of dynamic evaluation. /Author/