Submitted by Marc, who says:

Hi ! I enjoy the historical maps, especially. Here’s my all-time favorite historical map — a hand-made relief map of the Pittsburgh streetcar system, from 1910.

Transit Maps says:

Oh, I just love this, Marc! This fantastic map was included as part of a “Report on the Pittsburgh Transportation Problem” submitted to the mayor of Pittsburgh, William A. Magee, by consulting engineer Bion J. Arnold in December 1910, and the craftsmanship is altogether something wonderful. The map – or more precisely, a photograph of a superb three-dimensional model – simply shows the elevation along the routes of Pittsburgh’s street railways, with some spot heights labelled at important points. Altogether, it neatly and beautifully illustrates the biggest problem facing street railway transportation in Pittsburgh – the mountainous terrain surrounding the downtown core. The benefit provided by the Mount Washington tunnel – opened in 1904 and still in use by transit today – is noted in the narrative underneath the photograph of the map. If you look closely, you can see that some of the lines shown here still exist as part of Pittsburgh’s light rail system even today. The location of all the car barns, power houses and electrical substations are also shown on the map, though many of them are obscured in his photograph of the model.

The map does remind me of two other items in the Transit Maps archives. First, this astonishing relief map of the Pacific Electric streetcar system in and around Los Angeles in 1920. Like this map, a photograph was taken of a physical model, although in this case, the route lines were added to a print of that photograph and hand-tinted red. And then there’s this diagram from Frankfurt in 1913, which looks very similar to this map, but uses the relief along each line to indicate the number of passengers in that segment of track.

Here’s the text from underneath the map, reproduced for easy reading:

This is a photographic reproduction of a model showing both the location and elevation of the various routes of comprising the street railway tracks of the Pittsburgh Railway Company. The map is laid out on a horizontal scale of 2000 feet to the inch, and the elevations on a vertical scale of 200 feet to the inch (measured above normal river level). From this photograph the elevations can only be judged in perspective. It will, however, be apparent at a glance that transportation over the streets of Pittsburgh is accomplished with unusual difficulties. As the great majority of passenger traffic centers in the low lying “Point District,” nearly every line reaching the suburbs is obliged to ascend heavy grades, with the exception of the Second Avenue line to Homestead, the Penn Avenue and Butler Street line to Aspinwall, and the West Carson Street line to McKees Rocks. Pittsburgh’s most direct line to the east end – via Center Avenue – is handicapped by one of the worst hills, likewise the Federal Street-Perrysville Avenue line to Riverview Park District. The low level tunnel under Mt. Washington has evidently been the greatest benefit in reaching the South Hills suburban district and providing convenient interurban connections to the towns South of Pittsburgh.

Our final word: Phenomenal! I can’t even imagine the amount of time it took to conceive, design and fabricate this model – craftsmanship at its best!

Source: Hathitrust.org (includes the complete report if you fancy a read!)