USA Freeway System

This layer presents rural and urban interstate highways. It is part of the National Highway Planning Network, published by the Federal Highway Administration as part of the National Transportation Atlas Databases for the United States. It provides a comprehensive database of interstate highways and connectors and other highways from the nation's principal arterial highway system and the National Highway System. The data is generalized to improve draw performance and be used effectively at a national level. To download the data for this layer as a layer package for use in ArcGIS desktop applications, refer to USA Interstate Highway and Freeway System.本图层涵盖城乡州际公路（interstate highways）。本图层隶属于美国联邦公路管理局（Federal Highway Administration）发布的《国家交通地图集数据库》（National Transportation Atlas Databases）中的国家公路规划网（National Highway Planning Network）。该数据集收录了源自美国主要干线公路系统（principal arterial highway system）与国家公路系统（National Highway System）的州际公路、联络道路及其他公路的综合内容。为优化绘制性能并适配国家级场景下的高效应用，本数据已完成概化处理。若需下载适用于ArcGIS桌面应用程序（ArcGIS desktop applications）的本图层包（layer package），请参阅《美国州际公路与高速公路系统》（USA Interstate Highway and Freeway System）。