THE IMPACT OF ENERGY-RELATED TRANSPORTATION POLICIES ON TRAVEL DEMAND: METHODOLOGY AND CASE STUDY

This study is a first step in providing the analytic methodology for assessing the transportation impacts of energy and energy conservation policies. The methodology is designed to be used by transportation planning agencies which already have the capacity to produce travel demand estimates unconstrained by energy shortages or energy policies. The models estimate the incremental changes to those demand estimates which are expected to result from the policies. The modeling structure includes four components: (1) a Total Travel Model; (2) a Trip Rate/Trip Length Model; (3) a Trip Distribution Model; and (4) a Mode Choice Model. Model 1 uses an elasticity formulation to convert the price effect of an energy policy into a revised estimate of total household travel. Model 2 converts the latter into revised estimates of household trip rates and average trip length. Model 3 develops statistical relationships between average trip length and trip length distribution function, and uses them to distribute the total number of trips from each zone among all of the potential destination zones. Model 4 is applied to each interchange on the trip table to allocate trips between origin-destination pairs among the available travel modes. The application of the entire modeling structure to a sample of municipalities in New Jersey to test the impact of an illustrative set of energy conservation policies proved successful. It generated relatively small differences in travel behaviors reflecting roughly comparable policies, yet was able to handle the more radical impact of rationing policy. Only the latter had a substantial impact on total travel consumption.