Long before the current idea of putting Teslas in tunnels and calling it rapid transit, there was PRT, or Personal Rapid Transit. The idea was that many small carriages on guideways could take people directly to their intended destination anywhere along the route – described as a “horizontal elevator” by John Volpe, the U.S. Secretary of Transportation at the time.

In the early 1970s, Denver beat out 29 other cities around the U.S. and was given an $11 million grant to explore this new technology. This map was produced by the Rocky Mountain News to accompany an article about the project in October 1972. This looks like the original camera-ready artwork, complete with white paint touch-ups. The reproduction in the newspaper would have been much cleaner than this. The obvious hand-lettering for some of the road labels strikes me as a bit slap-dash, and I actually wonder whether the lighter parts of the map were meant to reproduce at all or are just there as a guide for the graphic artist to draw the final map on top of. PMT cameras generally just exposed either pure black or white unless a halftone screen was employed, so I could well believe that the lighter parts would just drop out during exposure. Yes, I operated one of these cameras for the first three or four years of my graphic design career…

Spoiler: the Denver PRT never got built, as public opinion rapidly turned against it once everyone realised there’d be elevated PRT guideways all over town (the plan was for over 100 miles of PRT track!) and the whole thing was going to be extraordinarily expensive. The initial 5.5-mile demonstration track shown here was originally estimated at $40 million, or around $248.7 million in today’s money.

More information on this weird chapter in Denver’s transportation history can be found in this article at the Denver Public Library.

Source: Denver Public Library