DEVELOPMENT OF COUNTY MOBILITY INDICES

As concerns for energy shortages and the environment mount, attention in transportation is being directed towards alternatives to the automobile. Few practical techniques can, however, be used by transportation planners and decision-makers for analyzing the tradeoffs that must be made between modes. One approach for understanding the relationship between transportation modes is to quantify each mode and to combine these values into measure of transportation mobility. The resulting indicator would serve as a tool in transportation decision-making. The primary objective of this article was to identify parameters characterizing transportation systems at the county level and to combine them, using stepwise linear regression, into an overall transportation index which included highway, railroad, air, and water modes of transportation. A secondary objective in compiling the index was to make use of readily available data sources. Rather than engaging in costly and time-consuming data collection, the engineer or planner could use statistics that have already been published by government agencies and trade associations.