Value of Life Cycle in Explaining Trip Making Behavior and Improving Temporal Stability of Trip Generation Models

摘要

Travel demand models are valuable tools in the transportation planning process; based on sound theory theybring a quantitative element to what is predominantly a political process. The forecasts output from thesemodels guide decision makers in the evaluation and selection of transportation programs and projects.Developing a better understanding of the factors that influence travel behavior, the changes in travelbehavior over time, and the variables that best capture these changes may lead to the development ofmodels that are more stable over time, increasing the analyst’s confidence in model results and leading tomore cost effective investment decisions.This paper investigates life cycle as one such class of variables. In this context life cycle is defined as thestage at which a family is in at a given point in time as it relates to factors such as the number and age ofadults in the household, the presence, number, and age of children, and worker status. Using variousstatistical tests to evaluate its usefulness, the paper presents evidence to indicate that life cycle has a stronginfluence on trip making behavior while also improving stability in trip rates over time. These findingssuggest that advanced trip generation models that accommodate more independent variables may lead toimproved models are more temporally stable and better capture the dynamics that influence trip making.