Suchergebnisse

Children's school travel mode is changing, especially away from walking and bicycling and towards private automobiles. Simultaneously we see warning signs from a public health standpoint as children are becoming less active. It has been suggested that walking and bicycling to or from school could help shift this trend, moving it towards greater activity, and researchers are therefore exploring choices of school-trip mode in relation to the pedestrian friendliness of the built environment. Mode-choice models are generally framed as multinomial logit (MNL) models. However, the limitations of MNL models can cause unrealistic effects when walking and bicycling are included with motorized modes. In this paper the focus is on accounting for individual-specific heterogeneity, since different children or families may have very different tastes or tolerances, such as travel time, when it comes to choosing between driving a private automobile, taking the school bus, bicycling, or walking to or from school. The results show that such heterogeneity exists, and that it is more important for nonmotorized modes than for the motorized modes. The results show that accounting for correlation across modes leads to more realistic marginal rates of substitution (cross-elasticities) across modes—in particular, an increase in the walking distance negatively affects the probability both of walking and of bicycling.

Recent years have witnessed widespread expansion of state and regional planning programs in the United States. A major purpose of these efforts is to reduce urban sprawl—low density, discontinuous, suburban–style development, often characterized as the result of rapid, unplanned, and/or uncoordinated growth— by promoting jurisdictional cooperation and regulatory consistency across metropolitan areas. This paper evaluates the efficacy of this approach by examining the relationship between governmental fragmentation and several measurable outcomes of urban development: density, urbanized land area, property value, and public expenditures on infrastructure. The four dimensions are modeled in a simultaneous equations framework, providing substantive evidence on how fragmentation and other exogenous factors affect metropolitan growth patterns. Fragmentation is associated with lower densities and higher property values, but has no direct effect on public service expenditures; less fragmented metropolitan areas occupy greater amounts of land due to the extensive annexation needed to bring new development under the control of a central municipality. The findings of the analysis lend support to state and regional planning efforts aimed at increasing cooperation among local governments, but also suggest that further research is needed in order to evaluate whether or not they produce their intended effects.

Bicycle usage has been on the rise in Iceland and other western nations, in part due to government policies intending to increase bicycling as a transportation mode. As city planners and transportation engineers move forward with the development of sustainable transport policies and designing the infrastructure that supports bicycle utilization of all forms, safety is paramount. Unfortunately, often resources and funding for these types of projects may be limited, leaving those in charge of planning needing to prioritize projects that will maximize benefits while being cost effective. This paper reviews the literature to identify important factors that have been found to either promote or decrease bicyclist safety. Then this paper will investigate bicycle crashes in Iceland that resulted in an emergency room visit using emergency room data. In this way the paper is able to explore bicycle crashes that do not involve automobiles, but police recorded data generally only contains bicycle-automobile crashes. The aim of this study is therefore to further enhance understanding of bicycle safety in general based on hospital records from emergency room visits.