 In 1916, the Good Roads Bill authorized federal funds for highway construction, which opened up roads in rural America to allow passage of mail.Today, as in years past, 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."