John Kay wonders in
the Financial Times why trains get funded when, “Building and
maintaining busways costs a small fraction of the price of a tramway
[light rail] and creates a fraction of the disruption.” He posits:

Where rail transport is concerned, serious cost benefit analysis
goes out the window… The answer seems to be that there is something
psychologically irresistible about vehicles on iron roads, although it
is difficult to know what it is. 

Explains some of the vehemence of support for the Triangle’s train to nowhere.