Essentially, transportation myopia involves people forgetting that transit competes with cars. As a result they often forget why they care about transit, and treat transit as a goal in itself.
If their goals relate to the environment, they may forget that transit only helps the environment by getting people out of cars. We see this with the Tappan Zee Bridge project, where anti-sprawl advocates have been pushing for transit, but few have questioned the State Department of Transportation's primary goal of widening the bridge from seven lanes to ten.
If people are concerned about the financial and political support that transit receives, they may forget that transit is competing for customers and for political supporters against the road/parking/gas/car system. We see this with the "Save the G" campaign, where advocates failed to address a multi-year, billion-dollar investment in rehabilitating and upgrading the G's primary competition, the Brooklyn-Queens Expressway.
Why do I need a name for this? So that I don't have to keep restating the reasons why it's a bad idea to consider the Q74 without mentioning the Kew Gardens Interchange, and so on and so on. I can just say, "Q74 advocates show transportation myopia," and link to this page. Less work for me, and perhaps most importantly, less than 140 characters.
A lot of transit advocates that I know and respect have demonstrated transportation myopia. If I call you out on it, it's nothing personal. We're on the same side, and I'm doing it to help you accomplish a goal that we all share. I've probably written some myopic things in the past, and you should feel free to call me out if I do it again.
