摘要: |
A growing number of parents accompany their children to and from school, to make sure they travel with the best care and minimum stress. Policies that aim at promoting nonmotorized modes of transportation or at least discouraging auto driving solely for the purpose of picking up or dropping off the kids may not be successful in practice unless primary concerns of parents are treated appropriately. School escorting decisions need to be investigated, as a decreasing trend in students' travel freedom also decreases the tendency toward the use of active modes of travel, complicates intrahousehold activities that need to be considered in travel demand models, and increases externalities (e.g., safety, energy, and environmental risks) of the transportation systems. Two separate three-level nested logit models are developed to explore escort decisions in trips to and from school. In addition to addressing escort model misspecification, the authors' models encompass a wide range of parental reservations such as safety and comfort that are typically ignored in previous research. A few policy sensitive variables, including commute distance, car ownership, income, and safety, were explicitly looked into and their influence on student escort behaviors was explained. Elasticities of the nested and multinomial logit models are compared to elaborate the consequences of model misspecification in terms of general conclusions and policy assessments. In some cases, the elasticities are even different in sign, and in some other cases elasticities of the nested logit are 16 times more than that of multinomial logit. Commute distance to school, which has a fundamental role in land-use decisions, for instance, is found to be sensitive to the model specification. |