Good public transit doesn't arrive overnight. When D.C.'s Metrorail first opened in 1976, it had only a handful of stations. Today, it is the second busiest rapid transit system in the U.S. Yet the District's population has actually gotten smaller over that period — from more than 750,000 residents in 1970 to fewer than 675,000 in 2015 (although it's been on the rise in more recent years), according to the most recent census. All any successful transit system needs is a sufficient and continuing revenue source to finance it beyond fares — much as roads and bridges have long benefited from motor fuel taxes. Transit's value to the nation's urban centers is well-documented, but the political will to make that investment (in new starts or repairs) appears to be sporadic, at best.