Marlon G. Boarnet

How the Built Environment Affects Physical Activity Views from Urban Planning

The link between the built environment and human behavior has long been of interest to the field of urban planning, but direct assessments of the links between the built environment and physical activity as it influences personal health are still rare in the field. Yet the concepts, theories, and methods used by urban planners provide a foundation for an emerging body of research on the relationship between the built environment and physical activity. Recent research efforts in urban planning have focused on the idea that land use and design policies can be used to increase transit use as well as walking and bicycling. The development of appropriate measures for the built environment and for travel behavior is an essential element of this research. The link between the built environment and travel behavior is then made using theoretical frameworks borrowed from economics, and in particular, the concept of travel as a derived demand. The available evidence lends itself to the argument that a combination of urban design, land use patterns, and transportation systems that promotes walking and bicycling will help create active, healthier, and more livable communities. To provide more conclusive evidence, however, researchers must address the following issues: An alternative to the derived-demand framework must be developed for walking, measures of the built environment must be refined, and more-complete data on walking must be developed. In addition, detailed data on the built environment must be spatially matched to detailed data on travel behavior.

CAN LAND-USE POLICY REALLY AFFECT TRAVEL BEHAVIOUR? A STUDY OF THE LINK BETWEEN NON-WORK TRAVEL AND LAND-USE CHARACTERISTICS

Planners are increasingly viewing land-use policy as a way to manage transport demand. Yet the evidence on the link between land use and travel behaviour is inconclusive. This paper uses travel diary data for southern California residents to examine the link between land-use patterns at the neighbourhood level and non-work trip generation for a sample of 769 individuals. The number of non-work automobile trips that an individual makes in a two-day period is modelled as a function of socio-demographic variables and land-use characteristics near the persons place of residence. The land-use variables are statistically insignificant in all but one of the specifications. The results suggest that choices about how to measure the variables and how to specify the regressions can influence the conclusions from these studies in potentially important ways. This underscores the need for continued careful attention to these research issues.

Spillovers and the Locational Effects of Public Infrastructure

This paper examines the possibility of negative output spillovers frompublic infrastructure. A model of productive public capital shows that when input factors aremobile, public infrastructure investments in one location can draw production away from otherlocations. In a linear production-function framework, this effect would be manifested as anegative output spillover from public capital. Using data for California counties from 1969through 1988, such negative spillover effects are shown to exist in the case ofstreet-and-highway capital. The data show that changes in county output are positivelyassociated with changes in street-and-highway capital within the same county, but outputchanges are negatively associated with changes in street-and-highway capital in other counties.

The influence of land use on travel behavior: specification and estimation strategies

While the relationship between urban form and travel behavior is a key element of many current planning initiatives aimed at reducing car travel, the literature faces two major problems. First, this relationship is extremely complex. Second, several specification and estimation issues are poorly addressed in prior work, possibly generating biased results. We argue that many of the latter problems are overcome by systematically isolating the separable influences of urban design characteristics on travel and then properly analyzing individual-level data. We further clarify which results directly follow from alternative land use arrangements and which may or may not, and thus identify the specific hypotheses to be tested against the data. We then develop more-reliable tests of these hypotheses, and explore the implications of alternative behavioral assumptions regarding travel costs. The measured influence of land use on travel behavior is shown to be very sensitive to the form of the empirical strategy.

Built Environment as Determinant of Walking Behavior: Analyzing Nonwork Pedestrian Travel in Portland, Oregon

Much has been written about the connection between land use/urban form and transportation from the perspective of affecting automobile trip generation. This addresses only half the issue. The theoretical advances in land use–transportation relationships embodied in paradigms such as the jobs-housing balance, neotraditional design standards, and transitoriented development rely very heavily on the generation of pedestrian traffic to realize their proposed benefits. The present analysis uses models and data sets similar to those used in previous work for the Portland, Oregon, area but applies them toward analysis of nonwork walking travel. The results suggest that regardless of the effects that land use has on individual nonwork walking trip generation, the impacts take place at the neighborhood level.

California's Safe Routes to School program: impacts on walking, bicycling, and pedestrian safety

Abstract This article evaluates Californias pioneering Safe Routes to School (SR2S) program, which funds traffic improvement projects designed to improve safety for childrens walking and bicycling to school and to increase the number of children who do so. Through surveys of parents and observations of vehicle and pedestrian traffic before and after project construction, we examined the impacts of 10 traffic improvement projects funded through the SR2S program. We measured changes in perceived safety and in safety-related behaviors associated with childrens trips to school, and examined changes in the number of children walking and bicycling following these improvements. Five of the 10 traffic improvement projects we evaluated showed evidence of a successful impact. The findings have implications for Californias SR2S program and for similar initiatives throughout the country.

A Broader Context for Land Use and Travel Behavior, and a Research Agenda

Problem: Planning studies of land use and travel behavior focus on regression analysis of travel as a function of traveler demographics and land use near study subjects’ residences. Methodological debates have tended to focus almost exclusively on the possibility that persons choose their residence based on how they wish to travel. This longer view steps back from the confines of the regression-based literature to explain the historical roots, methods, and results of the literature, and to assess how the land use–travel literature must be transformed to be more relevant to planning. Purpose: There are many summaries and meta-analyses of the impact of land use on travel. The goal here is not to understand how we might better specify a regression or summarize the results of past studies, but rather to explain how a literature that has become fundamental to planning scholarship is failing to be sufficiently planning focused. At the same time, this longer view describes how the literature can be transformed to address the planning challenges of today and tomorrow. Methods: This longer view summarizes over 100 articles, covering transportation methods from the dawn of the interstate highway era to topics that include program evaluation, land development, and cognitive aspects of travel behavior. The primary focus is on the land use and travel literature, but the review and analysis is broad ranging and places the literature and its challenges within the broader context of recent developments in the social sciences, planning, policy, and electronic data collection. Results and conclusions: This longer view elucidates three research frontiers that will be necessary to move the land use–travel literature forward. First, behavioral models of land use and travel must expand to consider how land is developed, how places are planned, and how cities are built. Second, the land use–travel literature should build a robust retrospective program evaluation tradition, which is currently almost completely absent in a scholarly field dominated by cross-sectional hypothesis tests and forecasting models. Third, economic social welfare analysis must be carefully researched, including questions of preferences for neighborhood types and whether such preferences are fixed or malleable. Takeaway for practice: Planning is about city building, and the literature and practice on land use and travel behavior should adapt to better support city building. This requires both a serious commitment to social science research and plannings characteristically broad view of context, problem, and place. In an era of climate change, and amidst debates about sustainability, the land use–travel literature must more aggressively examine the process of plans and place making, evaluate the increasingly innovative transportation policies being implemented at the local level, and develop methods that allow more informed discussion about the costs and benefits of transportation policies. Research support: None.

New highways, house prices, and Urban development: A case study of toll roads in orange county, Ca

Abstract We examine the link between highways and urban development by employing both hedonic analysis and multiple sales techniques to study the impact of the construction of toll roads in Orange County, California, on house prices. Urban economic theory predicts that if highways improve accessibility, that accessibility premium will be reflected in higher land prices. Our empirical analyses of house sales prices provide strong evidence that the toll roads, the Foothill Transportation Corridor Backbone in particular, created an accessibility premium; home buyers are willing to pay for the increased access that the new roads provide. Such willingness to pay influences both development patterns and, potentially, induced travel (the association between increases in highway capacity and increases in vehicle miles of travel). The results are consistent with the idea that induced travel is caused, in part, by changes in urban development patterns that are linked to increases in highway capacity.

Walking, Urban Design, and Health Toward a Cost-Benefit Analysis Framework

The authors examine the magnitude of health benefits from urban design characteristics that are associated with increased walking. Using geocoded travel diary data from Portland, Oregon, regression analyses give information on the magnitude and statistical significance of the link between urban design variables and two-day walking distances. From the coefficient point estimates, the authors link to the health literature to give information on how many persons would realize health benefits, in the form of reductions in mortality risk, from walking increases associated with urban design changes. Using a cost-benefit analysis framework, they give monetized estimates of the health benefits of various urban design changes. The article closes with suggestions about how the techniques developed can be applied to other cost-benefit analyses of the health benefits of planning projects that are intended to increase walking.

Highways and Economic Productivity: Interpreting Recent Evidence:

This article reviews the recent literature on public infrastructure and economic productivity, with special attention to the particular case of highway infrastructure. Recent evidence suggests that, at the margin, highway infrastructure contributes little to state or national productivity. This is consistent with studies that show relatively small land-use impactsfrom modem highways. Yet the idea that highways enhance economic health is common in the policy and planning communities. Two explanations can help reconcile this divergence between academic research and popular perception. First, some of the economic development observed near highways might not actually be caused by the highway. Second, some of the economic development near highways might be a shift of economic activity awayfrom other areas. Either explanation implies the need for reforms in highway project analysis and funding. This article suggests appropriate policy reforms and directions for future research.