ZipCodeBoundaryOD

U.S. ZIP Code Areas (Five-Digit) represents five-digit ZIP Code areas used by the U.S. Postal Service to deliver mail more effectively. The first digit of a five-digit ZIP Code divides the United States into 10 large groups of states numbered from 0 in the Northeast to 9 in the far West. Within these areas, each state is divided into an average of 10 smaller geographical areas, identified by the second and third digits. These digits, in conjunction with the first digit, represent a sectional center facility or a mail processing facility area. The fourth and fifth digits identify a post office, station, branch or local delivery area.美国五位数邮政编码区域（Five-Digit ZIP Code Areas）指的是美国邮政署为更高效地开展邮件投递而采用的五位数邮政编码区域。五位数邮政编码的首位数字将美国划分为10个大型州级群组，编号从东北部的0依次延伸至最西部的9。在这些大型州级群组范围内，每个州会被平均划分为10个更小的地理区域，由邮政编码的第二位与第三位数字共同标识。这两位数字与首位数字相结合，对应一个分区邮件处理中心或邮件处理场站区域。第四位和第五位数字则用于标识具体的邮局、支局、分支机构或本地投递区域。