Most, if not all, successful tourist railroads are located in areas that already have strong tourist draws apart from the railroad or are located close to major metropolitan areas. The Strasburg, Roaring Camp, D&S, GCRy and the WP&Y, to name a few, are all located in the heart of major tourist areas or are located in gateways to them. I doubt if stand alone tourist railroads can ever hope to duplicate the success of these lines. And the further they are located from population centers or off main travel arteries, the less their chances for success. As in real estate, it's all about "location, location and location.
Michael Allen