Evaluating the travel, physical activity and carbon impacts of a ‘natural experiment’ in the provision of new walking and cycling infrastructure: methods for the core module of the iConnect study
David Ogilvie, Fiona Bull, Ashley Cooper, Harry Rutter, Emma Adams, Christian Brand, Karen Ghali, Tim Jones, Nanette Mutrie, Jane Powell, John Preston, Shannon Sahlqvist, Yena Song
BMJ Open Jan 2012, 2 (1) e000694; DOI: 10.1136/bmjopen-2011-000694