Street and road data?

Question

Where do companies like Google and Yahoo and Mapquest get their street and road data? Is this a data source that the public has access to?

Answer 1

Companies often get their information from orbital remote sensing systems (the data they produce is often referred to as the Global Positioning System, or GPS). Some data sets are available, however some data such as military based data is not available for public viewing. The ArcGIS online system is a public source where the public can work with most publicly accessible sets of data.