UPDATE: The original version of this map was published in April 2015.
David Edmondson, who blogs about transportation at the Greater Marin, once used archival timetables to create a map of Marin's Northwestern Pacific Interurban commuter line, which shut down in 1941. Now he's done the same thing for the railroads that crisscrossed the Bay Area, painstakingly reconstructing the routes of every train in the region using a 1937 edition of the Official Guide to the Railways.
The resulting infographic mashes up the routes of bygone railways in one new, modern supermap.
"While we do have old maps showing where the rails were," Edmondson writes, "these are rail maps, not service maps."
To make the map, Edmondson copied the timetables of railways and analyzed their speeds, frequencies, and downtime at stations to create a visual service map.
As Edmondson told CityLab, parts of the old routes are still in use today: Caltrain still follows the blue lines from San Francisco to San Jose, and the forthcoming SMART train will trace part of the former Northwestern Pacific line from Cloverdale to San Rafael.
Edmondson also created rail maps in additional cities, including the Washington, DC–Baltimore region.