D.C.’s Department of Transportation scored a few supportive mainstream-media articles after its August 17 announcement that its Circulator bus service had boarded its four millionth rider sometime earlier that week. Four million is a lot, right?

Well, no. Metrorail handles that many trips in less than a week. And the 30 line, Metrobus’s busiest, carries that many passengers in about 200 days. It took the Circulator’s three routes approximately 760 days to reach the four million number. That means the service has carried, on average, about half the 10,000 to 11,000 daily passengers Circulator co-planner Dan Tangherlini projected in 2005. (Tangherlini’s number was for 2008 and may have been supplanted by later estimates. But if those exist, DDOT won’t release them.)

Secret numbers and boosterish press releases aside, the fact that the Circulator is struggling is revealed by DDOT’s regular tinkering with the Union Station to Georgetown line, the only one (almost) anyone uses. The latest attempt to boost low ridership partly undoes the last one: Half the buses will return to the original course, which entered Georgetown via K Street and turned back to Union Station at the intersection of Wisconsin Avenue and L Street. The rest will continue to follow the reroute instituted in March, taking M Street into Georgetown and continuing up Wisconsin Avenue to the Georgetown Safeway.

The latter route—which is longer, more congested, and thus slower—was designed to serve riders on the canceled Georgetown Metro Connection “Blue Buses” that ran from Foggy Bottom to upper Georgetown. That service was killed to reduce costs for its sponsor, Georgetown’s Business Improvement District, which also pays a small subsidy to the Circulator. But the end of that blue-bus line was also clearly intended to boost Circulator passengers, which apparently didn’t work.

The change will significantly reduce service levels for riders who need one of the two subroutes. Buses between Union Street and 20th & K Streets will maintain, if all goes well, the existing 10-minute headways. But the two Georgetown legs should see red Circulator buses only every 20 minutes or so. That should send some passengers back to where they came: Metro’s 30 and D lines, whose ridership the Circulator has cannibalized.

Perhaps someday DDOT will pay some attention to Metrobus, which carries most of D.C.’s bus riders. But it’s a lot simpler to keep dabbling with the Circulator, which can be manipulated with impunity precisely because its role in D.C.’s transportation system is so negligible.