In the olden days, selling goods from a store required physical access. People rode their horse, tied it up, etc. As a vendor, you knew this person could only come as far as a horse could take them. If you sold ice cream, that's about all you needed to know. If there was a bridge that was in disrepair and in danger of collapsing a mile from your shop, you'd advise your customers to avoid the bridge and take the 3-mile detour.