426 Journal of Physical Activity and Health, 2009, 6, 426-434 © 2009 Human Kinetics, Inc. Background: Efforts to increase community levels of physical activity through the develop- ment of multiuse urban trails could be strength- ened by information about factors predicting trail use. This study examined whether reasons for trail use predict levels of physical activity on urban trails. Methods: Adults (N = 335) living within a 1-mile buffer zone of urban trails in Chicago, Dallas, and Los Angeles completed a self-report measure assessing demographics, reason for trail use, and physi- cal activity on the trail. Accelerometers mea- sured total daily moderate-to-vigorous physi- cal activity (MVPA). Environmental features of the urban trail were assessed with the Sys- tematic Pedestrian and Cyclist Environmental Scan for trails measure. Multivariate regres- sion analyses were conducted that accounted for clustering of individuals within trail seg- ments. Results: After controlling for demo- graphic and environmental factors and total daily MVPA, reasons for trail use signiicantly predicted recreational but not transportation activity. Recreational trail activity was greater for participants who reported exercise and health reasons for trail use as compared with other reasons (ie, social interaction, enjoying nature, walking pets) for recreational trail use. Conclusions: To increase the use of urban trails, it may be useful to promote the health and exercise beneits of recreational trail use. Dunton, Spruijt-Metz, and Chou are with the Dept of Preven- tive Medicine, University of Southern California, Alhambra, CA. Wolch is with the Dept of Geography, University of Southern California, Los Angeles, CA. Jerrett is with the School of Public Health, University of California, Berkeley, CA. Byrne is with the Grifith School of Environment, Grifith University. Weaver is with the Weaver Research + Consulting Group. Reynolds is with the School of Community and Global Health, Claremont Graduate University. Reasons for Urban Trail Use Predict Levels of Trail-Related Physical Activity Genevieve Fridlund Dunton, Donna Spruijt-Metz, Jennifer Wolch, Chih-Ping Chou, Michael Jerrett, Jason Byrne, Susan Weaver, and Kim D. Reynolds Keywords: physical activity, environment, community-based research , survey research In recent years, there has been increasing research attention directed toward the role of environmental design features in population levels of physical activ- ity. 1–5 The development of walking and biking trails is an example of an environment-focused strategy to pro- mote physical activity within a community. In urban set- tings, where opportunities for physical activity may be limited by concerns such as trafic 1 and safety, 6 walking and biking trails could provide a convenient and cost- effective 7 approach to increasing physical activity among residents. Despite these potential advantages, there is some question as to whether people will become more physically active in response to the creation of community trails. Longitudinal and quasi-experimental studies have generated mixed results with regards to the beneicial impact of community trail development on walking and biking rates. 8–10 These results suggest that an “if you build it, they will come” approach to trail development might not be the most effective approach. Instead, it may be necessary to enhance the use of urban multiuse trails through environmental modiications, promotional strategies and messages, and targeted cam- paigns. The Task Force on Community Preventive Ser- vices recommends that the creation and enhancement of physical activity resources should be combined with informational outreach activities. 11 The elucidation of factors underlying community trail use serves as an important precursor to efforts in this area. A number of demographic 12–14 and environmen- tal 15–18 variables have been associated with community trail use. This research suggests that individuals with higher levels of education and income are more likely to use trails. In addition, environmental factors such as travel distance to the trail, hilly terrain, and busy streets have been associated with trail use. 18 However, less is known about how psychosocial and behavioral variables predict trail-related activity. An individual’s reason for using an urban trail is a largely unexplored construct that may provide insight on why some individuals use