In the late 1960s, Chicago actually seriously considered knocking down the elevated parts of the “L” and replacing it all with a modern subway network. The plan originally called for multiple lines, but these got whittled down over the years for a variety of reasons – lack of funding being one of the major ones.

By 1977, all that remained on the table was the Franklin Street Subway, shown in red in the handsome illustrated map above. It would have cut across to the western side of the Loop and passed directly under Sears Tower, which apparently was built to allow basement-level access to a planned station there. In effect, the subway would have acted as a downtown relief line, offering an alternative north-south corridor through the city.

This map was featured in the 1977 annual report for the Chicago Urban Transportation District (CUTD), the body created to oversee the project and raise some capital for it via a local sales tax. Note the white area on the map: this shows the district where the tax would have been levied.

By 1979, rising costs and shrinking funding sources sounded the death knell for the project, and the “L” continues to rise high above the streets of downtown Chicago.

Source: Chicago “L”.org website – lots more information about the history of this abandoned project here!

Update: Correspondent Dennis McClendon has provided the following information about the map’s creator, which is great to know:

We might mention the actual cartographer: Eugene Derdeyn, whose Perspecto Maps created similar Perspectovision oblique views-to-the-curved-horizon for a number of clients in the Chicago area. I think Derdeyn died in the 1990s and his daughter updated selected projects for a few more years.