Some claim that cardependent cities contribute to obesity by discouraging walking and bicycling. In this article, we use household activity data from the San Francisco region to study the links between urban environments and nonmotorized travel.

We used factor analysis to represent the urban design and land-use diversity dimensions of built environments. Combining factor scores with control variables, like steep terrain, that gauge impediments to walking and bicycling, we estimated discrete-choice models. Builtenvironment factors exerted far weaker, although not inconsequential, influences on walking and bicycling than control variables.

Stronger evidence on the importance of urban landscapes in shaping foot and bicycle travel is needed if the urban planning and public health professions are to forge an effective alliance against cardependent sprawl.

A good study looking at the factors influencing cycling and walking. The perspective is Cervero's usual framework, the three Ds: density, diversity and design. All three are found to have significant influences on bicycle usage, with the residential end being slightly more important. Of the urban form variables, the presence of neighbourhood retail is found to be the strongest predictor of walking.

From an evaluation standpoint, I wish these authors would standardize/normalize the coefficients of their models! After limiting to statistically significant variables, normalization would allow me to compare the relative influence of each variable on bicycle usage. It would also be extremely useful to include the mean and standard deviation of all input variables, to allow some rough comparisons to other study areas. If the input data has low variance (e.g., a uniformly low-density suburb), meaningful patterns could be missed.

Finally, the bicycle model seems pretty shoddy-the rho-squared value is only 0.13! Since it only considers factors at origin and destination, I imagine it's missing a massive amount of valuable data, like the topography, safety and quality of the route itself.

Keywords: active transportation, pedestrian planning, bicycle planning, urban form, bicycle modelling

After a quick read, my main criticism regards their choice of neighbourhood variables. I am not convinced that they are capturing “walkability” in their coarse residential sprawl index or “mixed-use” index. While these two variables are intended to capture density and diversity (ignoring design), they ignore the work environment and probably do a poor job of measuring the residential environment. They also tried using the Smart Growth America sprawl index, but this index is not local enough to capture the necessary neighbourhood-scale effects.

Additionally, I have to wonder about their sample-how many walkable environments were actually sampled? In the US, an unstratified sampling strategy would not include many walkable locations.

Finally, I have to wonder about time lags: their model only captures a change in BMI in the year following a move (when a change in sprawl/mixed use is observed). What about subsequent years?

That said, these weaknesses are present in many other papers in the literature, and they do bring some interesting perspectives and methodology to the table. The inclusion of occupation variables associated with strength and strenuousness was a valuable addition to modelling in this area. I'd need to read the paper more closely before I'd be prepared to defend my complaints, really.

Keywords: urban planning, active transportation, land use transport link

Keywords: bicycle planning, pedestrian planning, active transportation

Increases in per capita vehicle usage and associated emissions have spawned an increased the examination of the ways in which our communities and regions are developing. Associated with increased vehicle usage are decreased levels of walking and biking, two valid forms of physical activity. The Surgeon General's 1996 report, Physical Activity and Health, highlights the increasing level of physical inactivity as a growing cause of mortality. The costs and benefits of contrasting land development and transportation investment practices have been the subject of considerable debate in the literature. Findings have been refuted based on methodological grounds and inaccurate interpretation of data. Several of these studies, their methodological approaches, and their critiques are analyzed. While most agree that the built environment influences travel, considerable disagreement exists over the likely impacts of increased density, mix, and street connectivity on air quality, transportation system performance, and household activity patterns.

Keywords: urban planning, transport planning, active transportation, land use transport link

Obesity is a major health problem in the United States and around the world. To date, relationships between obesity and aspects of the built environment have not been evaluated empirically at the individual level. Objective

To evaluate the relationship between the built environment around each participant's place of residence and self-reported travel patterns (walking and time in a car), body mass index (BMI), and obesity for specific gender and ethnicity classifications.

Body Mass Index, minutes spent in a car, kilometers walked, age, income, educational attainment, and gender were derived through a travel survey of 10,878 participants in the Atlanta, Georgia region. Objective measures of land use mix, net residential density, and street connectivity were developed within a 1-kilometer network distance of each participant's place of residence. A cross-sectional design was used to associate urban form measures with obesity, BMI, and transportation-related activity when adjusting for sociodemographic covariates. Discrete analyses were conducted across gender and ethnicity. The data were collected between 2000 and 2002 and analysis was conducted in 2004.

Land-use mix had the strongest association with obesity (BMI>=30 kg/m^2), with each quartile increase being associated with a 12.2% reduction in the likelihood of obesity across gender and ethnicity. Each additional hour spent in a car per day was associated with a 6% increase in the likelihood of obesity. Conversely, each additional kilometer walked per day was associated with a 4.8% reduction in the likelihood of obesity. As a continuous measure, BMI was significantly associated with urban form for white cohorts. Relationships among urban form, walk distance, and time in a car were stronger among white than black cohorts.

Measures of the built environment and travel patterns are important predictors of obesity across gender and ethnicity, yet relationships among the built environment, travel patterns, and weight may vary across gender and ethnicity. Strategies to increase land-use mix and distance walked while reducing time in a car can be effective as health interventions.

A very useful addition to the debates on urban form. I'm a fan of anything bring active transportation into the debate, rather than just trying to reduce SOV trips. I'm curious about why they found land-use mix and walking distance to be statistically independent influences on obesity. Their speculation that it may be related to nutrition (and so-called “food deserts”) is an interesting idea.

Keywords: urban planning, transport planning, active transportation, urban form, land use transport link

Keywords: urban planning, transport planning, active transportation, urban form, land use transport link, urban planning

An increasing body of evidence suggests that moderate forms of physical activity (such as walking and bicycling), when engaged in regularly, can have important beneficial effects on public health. This article reviews current public health, planning, and urban design research to determine, first, how walking and bicycling might be critically important exercise behaviors for improving public health, second, how urban form affects the frequency of walking and bicycling as a form of physical activity, and third, how the public health considerations outlined in this article might reorient planners' thinking toward the realization of health-promotive environments. The current lack of emphasis on the interdependencies between built form and overall quality of life, as measured by health, safety, and welfare considerations, suggests the need for a rethinking of public policy approaches to transportation investment and land development.

Keywords: active transportation, urban planning, transport planning, urban form, land use transport link

Keywords: active transportation, urban planning, transport planning, urban form, land use transport link

Keywords: active transportation, urban planning, pedestrian planning, bicycle planning, urban form, transport planning, land use transport link

Keywords: urban planning, transport planning, active transportation, land use transport link, urban form

Findings from an empirical analysis to test the impacts of land-use mix, population density, and employment density on the use of the single-occupant vehicle (SOV), transit and walking for both work trips and shopping trips are presented. The hypothetical relationships tested focused on whether there is a relationship between urban form and modal choice, whether this relationship exists when controlling for non-urban form factors, whether this relationship is linear or nonlinear, and whether a stronger relationship exists between modal choice and urban form when they are measured at both trip ends as opposed to either the origin or the destination. A review of the literature and experiences suggested that a fair amount of information is known about the impacts of density on mode choice. However, considerable debate exists over whether density itself is actually the causal stimulus or a surrogate for other factors. To address this issue a data base was developed with a comprehensive set of variables for which density may be a proxy, for example, demographics and level of service. This analysis employed a correlational research design in which mode choice was compared among census tracts with differing levels of density and mix. Findings from this research indicate that density and mix are both related to mode choice, even when controlling for non-urban form factors for both work trips and shopping trips. Furthermore, the relationship between population and employment density and mode choice for SOV, transit and walking is nonlinear for both work and shopping trips. Transit usage and walking increase as density and land-use mix increase, whereas SOV usage declines. The findings from this research suggest that measuring urban form at both trip ends provides a greater ability to predict travel choices than looking at trip ends separately. The findings also suggest that increasing the level of land-use mix at the trip origins and destinations is also related to a reduction in SOV travel and an increase in transit and walking.

Solid research, with more convincing methodology than Sch96 (which I read at about the same time).

Overall, the most interesting result of the paper is the demonstration of nonlinearity. Figures 2 and 3 of their paper show a graph of modal share vs. employment density, and vs. population density. These graphs show that major increases in bus/walk modes only happen at employment densities greater than 125 employees/acre (work trips), or 13 residents/acre (shopping trips). The implications for policy are obvious: if you aren't going to reach those thresholds, you're wasting your time. Also, the employment graph shows substantial nonlinearity: between 75 and 125 employees/acre, there is essentially no change in mode share.

They also had some predictable results: walking trips were the most sensitive to increases in population density; it's worth considering densities at both trip ends (i.e., both residential population density and employment population density); etc.

Keywords: urban planning, transport planning, urban form, transit, active transportation, land use transport link

Keywords: active transportation

Keywords: active transportation

Keywords: active transportation, urban planning, pedestrian planning, bicycle planning, urban form, transport planning

Keywords: active transportation, urban form

Keywords: urban form, land use transport link, urban planning, active transportation

Some interesting stats on cycling and walking rates among the elderly in Germany and the Netherlands

Keywords: active transportation

Keywords: active transportation, urban form

Research in transportation, urban design, and planning has examined associations between physical environment variables and individuals' walking and cycling for transport. Constructs, methods, and findings from these fields can be applied by physical activity and health researchers to improve understanding of environmental influences on physical activity. In this review, neighborhood environment characteristics proposed to be relevant to walking/cycling for transport are defined, including population density, connectivity, and land use mix. Neighborhood comparison and correlational studies with nonmotorized transport outcomes are considered, with evidence suggesting that residents from communities with higher density, greater connectivity, and more land use mix report higher rates of walking/cycling for utilitarian purposes than low-density, poorly connected, and single land use neighborhoods. Environmental variables appear to add to variance accounted for beyond sociodemographic predictors of walking/cycling for transport. Implications of the transportation literature for physical activity and related research are outlined. Future research directions are detailed for physical activity research to further examine the impact of neighborhood and other physical environment factors on physical activity and the potential interactive effects of psychosocial and environmental variables. The transportation, urban design, and planning literatures provide a valuable starting point for multidisciplinary research on environmental contributions to physical activity levels in the population.

Keywords: active transportation, urban planning, urban form

Keywords: finance, pedestrian planning, bicycle planning, active transportation

Physically inactive lifestyles are a major public health challenge, and research in the transportation field on influences on the choice to walk and bike may provide guidance toward solutions. In the interests of promoting effective collaboration among the transportation, planning, and health fields, the current paper was written to fulfill three purposes. The first purpose was to summarize the transportation and planning studies on the relation between community design and non-motorized (“active”) transport and to interpret these studies from a health perspective. The second purpose was to summarize studies from the health literature that examine the relation between physical environmental variables and leisure-time physical activity that have relevance for transportation research. The third purpose was to promote more collaboration among transportation, planning, and health investigators by identifying opportunities for trans-disciplinary research.

Keywords: active transportation, transport planning

Keywords: active transportation

Keywords: active transportation, history, urban planning

Keywords: bicycle planning, pedestrian planning, active transportation