We know D.C. Get our free newsletter to stay in the know.

It was a day for diehard transit nerds. The first phase of Metro’s very long-awaited Silver Line opened on July 26 and gave Washingtonians access to an expansive network of Virginia suburbs they never knew they wanted. The line contains 11.6 miles of new tracks and five new stops that branch off from East Falls Church on the Orange Line, taking passengers all the way to Wiehle-Reston East by way of Tysons Corner. Phase two, slated to open in 2018 (which probably means 2019 or 2020), will run to Loudoun County and Dulles International Airport.

On opening day, hundreds of people caught a train from one of the new Silver Line stations. Some rode for practical reasons (i.e., to get to work); others took joyrides simply to say they were there on opening day. Metro sold commemorative Silver Line SmarTrip cards and gave away free pennants. Things were fancier at the last stop of the new line, Wiehle-Reston East, where a ceremony drew U.S. Transportation Secretary Anthony Foxx, Virginia Gov. Terry McAuliffe, and D.C. Mayor Vince Gray.

There was reason to celebrate: It was the Metro map’s first addition of a color since the Green Line opened in 1991. And the first phase of the $5.6 billion line was decades in the making. The new branch connects suburb-dwellers and commuters to D.C., and Washingtonians to business and commercial centers in Virginia. For places like Reston, there’s big hope that the Metro will spur development, bringing office buildings and yuppie condos.

Metro has touted what it says are high ridership numbers since the line’s opening. In September, Metro said the Silver Line was averaging 15,000 riders on weekdays, for a total of 30,000 new trips to or from one of the five new stations. (The new line did mean some declines in Blue and Orange line ridership numbers.) Metro is hoping for 25,000 Silver Line riders by next July.

But the new addition didn’t come without its problems. (It’s Metro, after all.) The opening yielded cuts to the Blue Line, and those riders weren’t happy about the resulting overcrowding and increased wait times. There’s simply not enough room for the Blue, Yellow, Orange, and Silver lines to traverse the Potomac on two crossings. Plus, the subway cars are outdated, and there’s serious question over whether the agency has enough equipment to accommodate new riders. Who’s ready for Phase 2?