Logit Models for Forecasting Nationwide Intercity Travel Demand in the United States

Nested and mixed logit models were developed to study national-level intercity transportation in the United States. The models were used to estimate the market share of automobile and commercial air transportation of 3,091 counties and 443 commercial service airports in the United States. Models were calibrated with the use of the 1995 American Travel Survey. Separate models were developed for business and nonbusiness trip purposes. The explanatory variables used in the utility functions of the models were travel time, travel cost, and traveler's household income. Given an input county-to-county trip demand table, the models were used to estimate county-to-county travel demand by automobile and commercial airline between all counties and commercial-service airports in the United States. The model has been integrated into a computer software framework called the transportation systems analysis model that estimates nationwide intercity travel demand in the United States.