For as long as I can remember, I have been fascinated by street rail systems (streetcars, cable cars, light rail, etc.). I find it exciting that cities are now going back to rail transit with new light rail systems, but it raises a question I’d like to offer.

Why do cities choose such systems over bus transit when they’re far more costly in terms of infrastructure installation and maintenance, and far less adaptable to routing changes that become necessary or advisable? (If I’m not mistaken, these are reasons for the earlier demise of once-extensive streetcar networks across the nation, notwithstanding the National City Lines campaign.)

Of course reducing air pollution by internal-combustion buses is a prominent incentive. (Even that can be alleviated with trolley buses with much less expense than light rail.) But "going green" certainly doesn't seem to be reason enough for all the additional investment in light rail that is chosen by municipal agencies that are certainly not enthusiastic railfans such as those of us on this board.

Comments?