Comparison of 1 km circular and road network buffers to measure access to food retailers for one school. The road network buffer is represented by the white area and the circular buffer encompasses both the white and gray areas. The school is represented by the flag in the centre of the circle and the food retailers are represented by the black circles.
Seliske et al. International Journal of Behavioral Nutrition and Physical Activity 2013 10:19 doi:10.1186/1479-5868-10-19