The investigator and collaborative team include: The University of Birmingham: P Adab (PI), T Barratt, KK Cheng, A Daley, J Duda, P Gill, M Pallan, and J Parry; the Nutritional Epidemiology Group at the University of Leeds: J Cade; the MRC Epidemiology high throughput screening compounds Unit, Cambridge: U Ekelund; the University of Edinburgh: R Bhopal; Birmingham City Council: S Passmore; Heart of Birmingham PCT: M Howard; and Birmingham Community Nutrition and Dietetic Service: E McGee. We thank the dedicated team of researchers at the University of Birmingham for managing and co-ordinating the project. “
“The effect of the built environment on

physical activity is a topical issue in public health (Shay et al., 2003). Interventions directed at the “walkability” of the built environment have been promoted to encourage healthy active living. Walkability is a complex concept, and definitions are varied as are approaches to operationalizing the concept using modeling techniques. The concept of walkability will continue to be context-specific until there exists a validated and consistent list of environmental correlates of walking. Many studies have examined the correlates of adult walking, with some consensus

that adult walking is related to density, mixed land use, pedestrian infrastructure (e.g. sidewalks, crosswalks) high connectivity (grid network, short Ketanserin block lengths, many intersections, few cul-de-sacs/dead ends) and accessibility ABT-199 to multiple destinations (Saelens and Handy, 2008, Saelens et al., 2003 and Shay et al., 2003). Walkability studies for elementary school children generally focus on walking to school, which has consistently been negatively associated with distance (Pont et al., 2009, Sirard and Slater, 2008 and Wong et al., 2011), and positively associated with population density (Braza et al., 2004, Bringolf-Isler et al., 2008, Kerr

et al., 2006, Kweon et al., 2006, McDonald, 2007, Mitra et al., 2010b and Wong et al., 2011). Associations with land use, pedestrian infrastructure and connectivity have been inconsistent and often contradictory to findings in adult studies (Pont et al., 2009 and Wong et al., 2011). Environmental features correlated with adult walking may be different than those for children because of differing destinations and purposes for walking. Varied methods of measurement for both built environment and walking outcomes may contribute to inconsistent results (Pont et al., 2009, Saelens and Handy, 2008, Sirard and Slater, 2008, Sirard et al., 2005 and Wong et al., 2011). Walking outcome has generally been measured through parent/child report using different outcome definitions (e.g. usual trip, trip per/week), time frames, and targeted age ranges.