The paper exposes some limitations of the abstract mode model based on the econometric theory as applied to transportation, and suggests modifications for improving its descriptive function as well as predictive capabilities for more accurate travel demand estimations. The modifications included model stratification by trip purpose, suggestions of significant forms of the explanatory variables entering the model, derivation of a time series model for travel forecasts, and the introduction of the dummy variable techniques for modal-split analysis. Habitual travel behavior which provides the theoretical background for the empirical analysis of any travel demand estimation, served as a basis for explaining the modifications. In order to illustrate the aforementioned proposals, versions of the abstract mode model were formulated by using a sample of city-pair data on the intercity passenger travel in West Virginia. A detailed discussion of model formulation procedures is presented. Thus, the aim of the proposed modifications to assist the accuracy of the abstract mode model is substantiated.