One impediment to streetcar construction in DC is that our local lords of historic preservation have decreed that there can be no overhead wires in the so-called “L’Enfant City” — the original planned City of Washington that includes the bulk of the offices and so forth. It’s worth pointing out that historic central cities in Europe seem to have no problem incorporating modern trams into their landscape. Here’s Berne:
And of course downtown Berne actually is historic, whereas the bulk of the L’Enfant City is composed of rather new and not-very-interesting buildings. A streetcar line to replace the heavily used north-south bus routes on 14th and/or 16th streets could be extremely useful and the lower operating costs would pay off relatively quickly on such heavily traveled routes.