ZIPCodesPlus4

Approximate polygon areas of ZIP Code + 4 routes for USPS. Created by geocoding address points through www.SmartyStreets.com on 03/23/2017, to retrieve ZIP codes for each point. Then grouped into polygons based on their ZIP+4 codes using Thiessen (Voronoi) polygons.本数据集为美国邮政署（USPS）的ZIP+4邮路近似多边形区域。其构建流程如下：于2017年3月23日借助SmartyStreets官方网站（www.SmartyStreets.com）对地址点进行地理编码，以获取每个地址点对应的邮政编码；随后依据各地址点的ZIP+4编码，采用泰森（沃罗诺伊）多边形算法将其聚合为多边形区域。