Attitudinal Market Segmentation Approach to Mode Choice and Ridership Forecasting: Structural Equation Modeling

The San Francisco Bay Area Water Transit Authority is evaluating expanded ferry service, as required by the California Legislature. As part of this process, Cambridge Systematics developed forecasts using a combination of market research strategies and the addition of nontraditional variables into the mode choice modeling process. The focus of this work was on expanding the mode choice model to recognize travelers' attitudes and different market segments. Structural equation modeling was used to simultaneously identify the attitudes of travel behaviors and the causal relationships between traveler's socioeconomic profile and traveler attitudes. Six attitudinal factors were extracted, and three of these were used to partition the ferry-riding market into eight segments. These market segments were used to estimate stated preference mode choice models for 14 alternative modes, which separated the travelers' reactions to time savings by market segment and which recognized that mode choices are different for market segments that are sensitive to travel stress or the desire to help the environment. The new mode choice models were applied within the framework of the Metropolitan Transportation Commission's regional travel model and calibrated to match modal shares, modes of access to each ferry terminal, ridership by route and time period, and person trips by mode at screening line crossings. Additional validation tests of significant changes in ferry service in recent years were used to confirm the reasonableness of the stated preference model. The model has been applied for three future year alternatives and to test the sensitivities of pricing, service changes, and alternative transit modes.