Rural delivery service - Wikipedia, the free encyclopedia
…the rural delivery service uses a network of rural routes traveled by carriers to deliver and pick up mail to and from roadside mailboxes. Formerly, an address for mail to a rural delivery address included both the rural route number and the box number, for example “RR 5, Box 10.” With the implementation of the 911 emergency system in many areas, it has become necessary to discontinue the old rural route numbers in those areas in favor of house numbers and road names as used on city routes. This change enabled emergency services to more quickly locate a rural residence.