In this case, because it zones all the living into one area and all the shopping into another area, usually by freeways. This requires people to have to drive to everything. In Europe, you quite often walk/bike to work, walk/bike to the grocery store, walk/bike to the park, etc. When we lived in the Netherlands, we had 2-3 grocery stores within a mile of our home, and an easy bike path to get there. So we biked every day, bought fresh food when we needed it instead of doing bulk shopping trips.