Yingling Fan

Neighborhood green, social support, physical activity, and stress: Assessing the cumulative impact

We estimate the cumulative stress mitigating impact of neighborhood greenness by investigating whether neighborhood green mitigates stress directly, and indirectly by encouraging physical activity and/or fostering social support. Using data from a recent community health survey in Chicago and two-stage instrumental variables regression modeling, we find that different components of neighborhood green play distinct roles in influencing stress. Park spaces are found to indirectly mitigate stress by fostering social support. Overall neighborhood vegetation is found to have direct stress mitigation impact, yet the impact is counteracted by its negative effect on social support. When comparing the effect size, park spaces show a more positive impact on health and well-being than the overall neighborhood vegetation level. Policy makers are recommended to focus on creating structured green spaces with public recreation and socialization opportunities rather than simply conserving green spaces in the neighborhood. Previous studies, as they often investigate the direct impact only and rarely use multiple measures of greenness, may have mis-estimated health benefits of neighborhood green.

Urban Form, Individual Spatial Footprints, and Travel: Examination of Space-Use Behavior

Physical planning can benefit from deeper insight into the space-use options that individuals have. This paper examines how individuals’ uses of space are related to urban form factors at their residences, after controlling for traffic congestion, weather, and individual or household characteristics. The behavioral data analyzed came from the 2006 Greater Triangle Region Travel Study in North Carolina. Individuals’ uses of space were measured by daily activity space–the minimum convex polygon that contains all the daily activity locations–and daily travel distance, and were estimated by the use of spatial regression models. The results showed that the residents of densely developed neighborhoods with more retail stores and better-connected streets generally have a smaller area of daily activity space and a shorter daily travel distance. In addition, urban form factors were compared in terms of their importance in explaining individuals’ space-use behavior. It was found that retail mix and street connectivity are key factors relating to individuals’ uses of space, whereas building density was less important. The findings shed light on possible land use solutions toward the better coordination of services in space.

Winners or Losers: Resident Perceptions of Transit-Induced Neighborhood Change

Existing research rarely goes beyond individual dimensions of neighborhood change to explore the broader neighborhood impacts of transit investments as perceived by neighborhood residents. To fill gaps in this knowledge, the residents of selected neighborhoods along four transit corridors in the Twin Cities area of Minnesota were surveyed. Survey results show that residents of the study neighborhoods had generally positive perceptions of transit-induced neighborhood change. However, significant differences existed between urban and suburban areas and between individual neighborhoods. In addition, African-Americans, immigrants, frequent transit users, carless residents, and new residents in general had more positive perceptions of transit-induced neighborhood change than did whites, nonimmigrants, infrequent or nontransit users, residents with access to a motor vehicle, and longtime residents. Asian urbanites had more negative perceptions. Implications of these findings are discussed.

Family functioning as a mediator between neighborhood conditions and children's health: Evidence from a national survey in the United States

This study examines whether the associations between neighborhood conditions and childrens health can be indirect and operate through aspects of family functioning. We use data from the 2007 National Survey of Childrens Health in the United States with the interviewed parents/guardians as the only source of the data. Our study sample includes 53,023 children aged between 6 and 17 years. Using structural equation modeling, we test both direct and indirect relationships between a family functioning index, a general indicator of childrens health status, and three neighborhood factors: neighborhood physical resources, environmental threats, and collective efficacy. Covariates in the analysis include gender, age, income, race, family structure, parental education, and health insurance coverage. All the three neighborhood factors show direct associations with childrens general health status, as well as indirect associations mediated by aspects of family functioning. Among the three neighborhood factors, collective efficacy and environmental threats are found to have much stronger associations with childrens general health than physical resources. When designing health-promoting neighborhoods for children and families, it may be more efficient for urban planners and health professionals to focus on community programs that reduce environmental stressors and foster neighborhood cohesion than programs that solely improve physical infrastructure. This study also verifies that aspects of family functioning mediate the associations between neighborhood conditions and childrens health. It is recommended that both family and neighborhood are critical points for child health intervention.

The Planners’ War against Spatial Mismatch: Lessons Learned and Ways Forward

Most existing reviews on spatial mismatch have focused on its causes and consequences rather than the successes and failures of planning practices for addressing this problem. This review article contributes to the literature by classifying spatial mismatch mitigation strategies into four groups and evaluating the successes and failures of each strategy group. The evaluation finds that empirical evidence on most strategies is inconsistent and the effectiveness of those strategies remains unclear, yet research examining car ownership programs consistently shows positive effects. The article concludes by recommending planners to expand their support for car ownership programs, test the effectiveness of the more recent, coordinated policy programs, and pay attention to nonspatially related employment barriers such as discrimination, social support, and human capital factors.

Drive or Walk? Utilitarian Trips Within a Neotraditional Neighborhood

An extensive body of literature has developed on the relationship between the physical environment and travel behavior. Although many studies have found that neotraditional neighborhood development supports nonautomobile travel by providing good street connectivity, pedestrian and cycling facilities, and internal destinations, questions remain about the travel behavior of individuals within such neighborhoods. This study uses travel diaries to examine utilitarian trip-making behavior within a neotraditional neighborhood and compares total trips with mode-specific (i.e., walk and drive) trips. Negative binomial regression is used to examine the effect of a set of independent variables, including personal and household characteristics, select attitudinal factors, and distance from residences to the commercial center. It is found that within the neotraditional neighborhood, walk trips drop off quickly with increasing distance to destinations, whereas drive trips increase. The analysis demonstrates the importance of short distances for within-neighborhood travel and the merit in considering trips separately for walk and drive modes to avoid obscuring important factors associated with trip making.

Traveler Information Delivery Mechanisms: Impact on Consumer Behavior

Advanced traveler information systems (ATISs) help individuals make informed travel decisions. Current ATIS applications encompass a variety of delivery mechanisms, including the Internet, telephone, television, radio, variable message signs, and in-vehicle navigation devices to support decisions about destinations, travel mode, departure time, routes, parking, and trip cancellation. It is important for researchers and practitioners to review the status of ATIS technologies and to understand travelers’ access and response to current ATIS deployment. Focusing on largely public-sector delivery mechanisms, this study answers two fundamental questions: whether accessing more information sources is associated with a higher likelihood of travel decision adjustments and which technologies are more likely to elicit substantive adjustments to routine travel. These questions are answered by using a comprehensive and recent behavioral data set, collected in the Research Triangle area of North Carolina. The study generates useful knowledge about how to operate existing traveler information systems more efficiently and how to improve them in the future.

Exploring the Influences of Density on Travel Behavior Using Propensity Score Matching

The causality issue has become one of the key questions in the debate over the relationship between the built environment and travel behavior. Since a residential self-selection effect exists, it is important to know if the observed influence of the built environment on travel behavior diminishes substantially once we control for self-selection. Using 5537 adult respondents to the 2006 Great Triangle Travel Survey in North Carolina, this study applied the propensity score matching approach to identify the causal effect of density on travel behavior and the relative contribution of self-selection to travel behavior. The results showed that, after removing self-selection bias, residents living in high-density neighborhoods travel, on average, 3.31 fewer miles per person per day than those who live in low-density neighborhoods. Self-selection effects account for 28%, 64%, and 49% of the observed influences of density on personal miles travelled, driving duration, and transit duration, respectively. We also found that different modeling approaches produce different point estimates, and that interval estimates of treatment effects tend to have a large variation. This points to a caveat of using point estimates to evaluate the impacts of the built environment on travel behavior.

Evaluation of Miami-Dade Pedestrian Safety Demonstration Project

This studys purpose was to implement a comprehensive program to reduce pedestrian deaths and injuries among pedestrians in a large urban environment. Miami–Dade County, Florida, was selected as the studys focus. High-crash locations were targeted for countermeasure implementation and analysis. With pedestrian crash data (1996–2001), four zones within the county were identified as having abnormally high pedestrian crash experience. On the basis of crash characteristics and pedestrian factors (age, ethnicity), 16 education, enforcement, and engineering treatments were implemented to reduce pedestrian crashes in the four zones and countywide. A before-and-after study was used with three control groups to evaluate the effects of the pedestrian safety program on pedestrian crashes. A 3-year “after” period was used (2002–2004). Multivariate intervention autoregressive integrated moving average time-series analysis was used, along with nonparametric U-tests to test for statistically significant differences in pedestrian crash experience. Results showed that at the peak of the program effects in 2003 and 2004, the pedestrian safety program reduced countywide pedestrian crash rates by anywhere from 8.5% to 13.3%, depending on which control group was used. These effects translate to approximately 180 fewer crashes annually in the county, or 360 pedestrian crashes reduced for 2003 and 2004 combined, based on the more conservative 8.5% crash reduction. Countywide, the greatest crash reductions were found among children and adults as a result of the program. Educational and other measures to reduce crashes involving older pedestrians showed no effect. A number of lessons learned were identified for future program implementation.

Is Sprawl Associated with a Widening Urban–Suburban Mortality Gap?

This paper examines whether sprawl, featured by low development density, segregated land uses, lack of significant centers, and poor street connectivity, contributes to a widening mortality gap between urban and suburban residents. We employ two mortality datasets, including a national cross-sectional dataset examining the impact of metropolitan-level sprawl on urban–suburban mortality gaps and a longitudinal dataset from Portland examining changes in urban–suburban mortality gaps over time. The national and Portland studies provide the only evidence to date that (1) across metropolitan areas, the size of urban–suburban mortality gaps varies by the extent of sprawl: in sprawling metropolitan areas, urban residents have significant excess mortality risks than suburban residents, while in compact metropolitan areas, urbanicity-related excess mortality becomes insignificant; (2) the Portland metropolitan area not only experienced net decreases in mortality rates but also a narrowing urban–suburban mortality gap since its adoption of smart growth regime in the past decade; and (3) the existence of excess mortality among urban residents in US sprawling metropolitan areas, as well as the net mortality decreases and narrowing urban–suburban mortality gap in the Portland metropolitan area, is not attributable to sociodemographic variations. These findings suggest that health threats imposed by sprawl affect urban residents disproportionately compared to suburban residents and that efforts curbing sprawl may mitigate urban–suburban health disparities.