gadgetbahn

A transportation concept or implementation that is touted as futuristic or innovative, but in execution turns out to be more expensive and less feasible than traditional means, outweighing their usefulness. Examples include but are not limited to Monorails (most often cited example) Personal Rapid Transit, Maglev, etc, versus traditional means generally referring to rail, subway, and road infrastructure

The term generally carries a negative connotation, in that the solutions may be seen as an expensive 'white elephant' in the truest sense: more difficult and more expensive to maintain and add to without any perceived benefit other than looking cool

References:

Wiktionary, gadgetbahn
Wikipedia, White Elephant disambiguation

Walt Disney World can't afford to expand their monorail, it costs a million dollars a mile for new track, and with the money it would take to expand that gadgetbahn they could buy a whole fleet of buses that fit their existing needs