Found a neat site with lots of historical research on the railroad that was never completed, but which became partially the route of the Pennsylvania Turnpike. One of the interesting details to contemplate would have been a second interchange for the East Broad Top at Burnt Cabins, Pa.--and that this interchange would have been with what was a Vanderbilt (NYC) backed line.

It's also interesting to note that while this would have been a very well built line, it would still be considerably steeper than most of the "Water Level Route." That makes one contemplate the possibility that the NYC's motive power development may have changed a bit, at least to having a route with some "mountain power" on it.

http://www.southpennrailroad.com/

A photo site on the same road:

http://sopennrr.tripod.com/

Herb Harwood found this to be a fascinating subject, enough to write a book about it.

http://www.amazon.com/Railroad-That-Nev ... 0253355486

Finally, the turnpike itself has had changes over the years, and some abandoned sections can still be seen.

http://www.abandonedturnpike.com/

Explore and enjoy.

there have been many RR's, interurbans plans started, construction started, but it fell out or something changed in the plans.

When I lived NW of Ft Wayne there was a planned interurban right across the road where I lived, graded, but no track down ever.

Denver Laramie and Northwestern had graded ROW towards Laramie but thats where it ended, but did actually exist as an operating railroad around Denver. You may still find the grading out there. I think the book on Narrow Gauge railways of America describes numerous NG starts but never completed (but planned or never got off the drawing board)