There’s a very strong relationship between a transit system’s cartographic representation and its user efficiency. Henry Beck’s iconic London Underground map was an instant success with the public precisely because it showed a ‘clear and consistent visual of the lines, where they cross and the order of the stations, without the confusion of earlier geographical maps which contained background information such as streets’. Research suggests that the way planners choose to represent their systems in public maps has ‘a tremendous impact on a passenger’s perceptions and his or her usage of the transit system’.
The Tyne & Wear Metro map’s apocryphal designers adopted its ubiquitous pretzel representation early on. The layout is unique in that it shows a line crossing over itself and at the time of opening was the only system in the world using this visual motif.
In 1969 early proposals for the system used purely geographical maps like this one, showing topographical contours.
By 1971 planning documentation was using an early version of the pretzel. The only surviving topographical feature was the River Tyne.
After several iterations showing incomplete sections of the system, this was the final map used in 1982 when the Metro opened fully.
Although the map has remained largely the same since its introduction, there have been some subtle changes over time. Metro seem undecided over the best way to represent the left hand vertical line, which crosses over the Tyne from Gateshead into Newcastle city centre’s stations. In the original map above it slants to the right.
In this early 2000 version, however, the line is parallel.
… and the map’s most recent iteration has the line slanting to the left.
Although the Metro’s transit map is abstract and quite difficult to imagine as geographically accurate, you can see from the below topographical representations that it is closer to reality than you might think.
It’s interesting to see how the network is cartographically rendered for technical purposes at Metro Control in South Gosforth. Jonathon Hurley’s photo above shows a panoramic view of the mimic diagram used for signal control.
Metro even designed a map for the test track in North Tyneside where prototype cars were tested under a variety of conditions between 1975 and 1980.
 London Underground: Station Design Idiom (2015): 37
 Zhan Guo, ‘Mind the map! The impact of transit maps on path choice in public transit’, Transportation Research Part A 45 (2011): 625.