A printed transit system map is a specific representation of a transportation network, typically covering an entire urban area. In comparison to interactive guides offered by services such as Google, such a transit system map is subject to limitations of scale and range of information for users. Transit maps from London, New York, and Paris show evidence of consensus by designers and map publishers on what information is required and how to graphically convey it. Indications of streets and surface geography show some divergence and reveal conceptions of local identity and wayfinding. In addition to their functional role subway or metro system maps have attracted attention as design artifacts.
The design approach taken by Henry Beck and later adapted by Massimo Vignelli restricted the complex reality of transit lines to a limited number of angles. Advocates for network maps based on this technique claim greater understanding by users. Writers of books on transit have been gathering rules of thumb and formulating design guidelines. Separately, design guidelines for bus system maps have been produced. Both these guidelines and individual maps produced by transit map publishers are good candidates for further investigation concerning the user-centered design process. Given the growing use of interactive itineraries and other tools, the role of printed maps should be evaluated from the perspective of a diverse group of users. These users benefit from public information systems and should not be forced to adopt unnecessary technology.