We measured and tested whether the following variables affect walking (basis: 200m buffer around each child's shortest walking path): number of busy intersections crossed, intersection and street density, total daily vehicle-miles traveled, average vehicle speed along the route, population density, and land use (R Wilson, 2008). Sidewalk coverage data do not exist for Roseville and could not be tested in the model. We refined the model through systematic testing of independent variables as the differ- ence in log-likelihood independent irrelevant alternatives is not a large concern: the travel survey sample has known travel choices and school district officials confirmed that nearly all children travel to school via.
