Kelly J. Clifton

Quantitative analysis of urban form: a multidisciplinary review

This paper characterizes and reviews multidisciplinary approaches to urban form. It begins by classifying quantitative approaches to analyzing urban form into five classes: landscape ecology, economic structure, surface transportation, community design, and urban design. It then reviews quantitative measures in each class. Based on the review, four conclusions are drawn. First, over the last two decades substantial progress has been made in the ability to measure and analyze spatial patterns that help characterize urban form. Second, at multiples scales and for a variety of reasons, there are advantages to development that is mixed and compact. Third, normative principles and policies for addressing urban form need to be crafted at multiple scales and carefully designed to address the disparate issues that arise at each scale. Fourth, with so many disparate measures now used to operationalize the same constructs, it would advance urban form research to have some standardization in operational definitions and measurement protocols.

The environment and urban adolescents' use of recreational facilities for physical activity: a qualitative study.

Purpose. Investigate environmental factors influencing the use of recreational facilities for physical activity by urban African-American adolescents. Design. Qualitative in-depth interviews and direct observation. Setting. Two public high schools and 24 public recreational facilities in Baltimore, Maryland. Participants. Forty-eight African-American adolescents aged 14 to 18 years. Methods. Data from 48 in-depth interviews and 26 observations were coded using NVivo software and analyzed using the constant comparative method. Results. Facility use is influenced by characteristics of the physical, social, organizational, and economic environments. Adolescents are attracted to low-cost, well-maintained facilities that offer preferred activities and that are within close proximity to home. Adolescents with limited access to facilities use alternative play spaces, like the streets or vacant lots, where they risk injury from falling or being hit by a car. They are drawn to facilities where they find active adolescents, and they avoid those where young people are engaged in drug or gang activity. Concerns about facility safety largely determine use, particularly for adolescent girls. Conclusion. Previous research points to the importance of increasing facility availability as a means of promoting physical activity, particularly in minority communities in which availability is disproportionately limited. This study shows that, while availability is important, additional facility characteristics should be considered when using environmental change to promote facility use for physical activity.

Examination of Traveler Responses to Real-Time Information About Bus Arrivals Using Panel Data

In recent years, a considerable amount of money has been spent on intelligent transportation system projects for public transportation, most notably, real-time transit information systems. To date, strikingly few studies that have empirically investigated the effects of deployment of such a system have been completed. This paper examines the effects of real-time transit information on travelers’ behavior and psychology. The 2006-2007 University of Maryland (College Park) campus transportation panel survey data were used to examine how travelers responded to the ShuttleTrac system, a newly implemented real-time bus arrival information system for the universitys shuttle service. Two fixed-effects models and five random-effects-ordered probit models were estimated to sort out the causal relations between ShuttleTrac system information use and two behavioral and five psychological indicators, respectively. It was found that use of the real-time information significantly increased the riders’ feelings of security about riding the bus after dark and boosted their overall level of satisfaction. However, it was not found to significantly increase travelers’ shuttle trip frequency, at least in the short term, perhaps because of a lack of enough time for adjustment of travel behavior. These results suggest that although transit agencies and scholars should not be too optimistic about achieving an immediate ridership increase by providing real-time information to travelers, they can expect positive psychological responses from transit riders.

Do you see what I see? - correlates of multidimensional measures of neighborhood types and perceived physical activity-related neighborhood barriers and facilitators for urban youth.

OBJECTIVESnTo classify types of neighborhood environment and to examine the gender-specific cross-sectional associations between these neighborhood types and adolescents perceptions of physical activity-related neighborhood barriers and facilitators.nnnMETHODSnThis cross-sectional study was conducted with a sample of 350 high school students in Baltimore, Maryland, in 2006. Participants completed the Neighborhood Environment Walkability Scale (NEWS). Objectively GIS-measured attributes of urban form came from various sources. Classification of built environment/neighborhood types was achieved by factor analysis and cluster analysis.nnnRESULTSnFour neighborhood types were identified: (1) arterial development; (2) inner-city area; (3) suburban residential; and (4) central business district. Girls who lived in suburban residential areas were less likely than their central business district counterparts to perceive the protective effects of crosswalks and pedestrian traffic signals. Girls living in inner-city neighborhoods were more likely than their central business district counterparts to perceive the traffic as being slow. Boys perceptions of their neighborhood did not vary by neighborhood pattern.nnnCONCLUSIONSnGirls appear to be more sensitive to their environment and perceive more physical activity-related built environment barriers compared to boys. Efforts to overcome physical activity barriers salient for adolescent girls should be tailored to the type of neighborhood.

Influence of Transportation Access on Individual Firm Location Decisions

Several studies of transportation and economic development impact have recognized the extent to which transportation investments may improve access to markets and, by doing so, influence firms location decisions. A study specified and empirically tested a firm-level model that captures the relationship between the propensity of a particular firm to relocate from its current business location as a function of local and regional accessibility, agglomeration economies, firm-specific characteristics, business-specific activity attributes, attitudes toward regional considerations, and factors that influenced the initial business location decision. The geographic area of analysis considers a four-county region in Maryland. The econometric analysis establishes significant association between transportation supply and firm-level relocation decisions in the study area and underscores the role of other firm and area-of-influence attributes in this process. The findings suggest a positive association between access...

Economic activity and transportation access : An econometric analysis of business spatial patterns

Several studies of transportation and economic development impacts have recognized the extent to which changes in accessibility triggered by transportation improvements may translate into business cost savings and contribute to a regions economic competitiveness. This paper specifies and empirically tests a general model that captures the intensity of business activity (at the zip code level) as a function of local and regional accessibility, agglomeration economies, and region-specific effects. The geographic area of analysis is a four-county region in Maryland. The econometric analysis establishes a significant association between transportation supply and business activity in the study area. The findings suggest a clear positive association between access to primary highway facilities and the level of economic activity. The results also confirm expectations that roads with higher functional form and capacity are likely to be spatially associated with a higher intensity of economic activity. The models...

Comparing objective measures of environmental supports for pedestrian travel in adults

BackgroundEvidence is growing that the built environment has the potential to influence walking--both positively and negatively. However, uncertainty remains on the best approaches to representing the pedestrian environment in order to discern associations between walking and the environment. Research into the relationship between environment and walking is complex; challenges include choice of measures (objective and subjective), quality and availability of data, and methods for managing quantitative data through aggregation and weighting. In particular, little research has examined how to aggregate built environment data to best represent the neighborhood environments expected to influence residents behavior. This study examined associations between walking and local pedestrian supports (as measured with an environmental audit), comparing the results of models using three different methods to aggregate and weight pedestrian features.MethodsUsing data collected in 2005-2006 for a sample of 251 adult residents of Montgomery County, MD, we examined associations between pedestrian facilities and walking behaviors (pedestrian trips and average daily steps). Adjusted negative binomial and ordinary least-squares regression models were used to compare three different data aggregation techniques (raw averages, length weighting, distance weighting) for measures of pedestrian facilities that included presence, condition, width and connectivity of sidewalks, and presence of crossing aids and crosswalks.ResultsParticipants averaged 8.9 walk trips during the week; daily step counts averaged 7042. The three aggregation techniques revealed different associations between walk trips and the various pedestrian facilities. Crossing aids and good sidewalk conditions were associated with walk trips more than were other pedestrian facilities, while sidewalk facilities and features showed associations with steps not observed for crossing aids and crosswalks.ConclusionAmong three methods of aggregation examined, the method that accounted for distance from participants home to the pedestrian facility (distance weighting) is promising; at the same time, it requires the most time and effort to calculate. This finding is consistent with the behavioral assumption that travelers may respond to environmental features closer to their residence more strongly than to more distant environmental qualities.

Neighborhood environment, self-efficacy, and physical activity in urban adolescents.

OBJECTIVESnTo test the pathways between perceptions of built environment factors and physical activity in urban youth.nnnMETHODSnThree hundred fifty high school students perceptions of neighborhood, and barrier self efficacy were measured by a Web survey. Physical activities were assessed using a one-week diary and accelerometers.nnnRESULTSnLand-use mix/accessibility and neighborhood satisfaction had direct pathways to walking. Barrier self-efficacy had a direct pathway to walking. In addition, land use, specifically neighborhood accessibility, influenced adolescents walking behavior via self-efficacy. Similar pathways were found in MVPA models.nnnCONCLUSIONSnNeighborhood factors appear to work together with self-efficacy to facilitate physical activity.

Reexamining ICT Impact on Travel using the 2001 NHTS Data for Baltimore Metropolitan Area

Information and communications technology (ICT) creates rich opportunities for individuals to reduce economic and social costs associated with their spatial interaction with others. The potential effects on travel behavior, however small individually, can aggregate substantially because ICT is rapidly permeating all aspects of our daily lives (Golob and Regan, 2001). Given that ICT usage necessarily involves reallocation of time and resources, it is conceivable that public policy could play an important role in facilitating desirable changes in travel outcomes by influencing the spatial and temporal reorganization of individuals’ activities (Shen, 2004). The last decade has witnessed a growing number of empirical studies on the relationship between ICT and travel (see, for example, Handy and Yantis, 1997; Johansson, 1999; Mokhtarian and Meenakshisundaram, 1999; Harvey and Taylor, 2000; Hjorthol, 2002; Farag et al., 2003; Fadare and Salami, 2004; Nobis and Lenz, 2004; Srinivasan and Athuru, 2004). These research efforts have undoubtedly broadened and deepened our understanding of the multidimensional, multidirectional, and complex ICT-travel connection. However, due to data and methodological limitations, such as small sample size, inadequate measurement of ICT usage, and lack of experimental design, there are many gaps in the existing knowledge about the actual and potential impacts of ICT on travel. The knowledge base must be strengthened in order to effectively support transportation planning and policy making for achieving the full benefits of ICT. This empirical study aims to gain additional insights into the relationship between ICT and travel using the 2001 National Household Travel Survey (NHTS) data, which contain a large sample of households and individual members and

Incentives, Regulations and Plans

This unique book allows readers to compare analyses of how North American states and European nation-states use incentives, regulations or plans to approach a core set of universal land use issues such as: containing sprawl, mixed use development, transit oriented development, affordable housing, healthy urban designs, and marketing smarter growth.