If everyone drives to a sold-out game at the new Nationals stadium, the result will be a mess.

That was the unstated message of the Aug. 2 “open house” held to brief D.C. residents on the Traffic Operations and Parking Plan (TOPP) for the stadium, which is scheduled to open for the 2008 baseball season. Representatives of Metro, D.C.’s transportation department, and consulting firm Grove/Slade Associates were on hand to explain the various TOPP maps and graphs. But none of them could say what will happen if most Nats fans drive, or if they ignore the complicated game-days scheme for traffic flow, street closings, color-coded parking sectors, and on-street parking restrictions.

Anyone who perused the maps, or walked the nearby streets, would have noticed that the site of the under-construction stadium is less accessible than RFK, the team’s current home. It’s served by one Metro line rather than two and can be reached by fewer major thoroughfares and bus routes.

At least there are some ideas about remedying the latter problem. The stadium’s opening might spur extensions of the N22 Union Station-Navy Yard shuttle (whose conversion to Circulator service is being considered) and the 7th Street Circulator line. Also possible, in theory, is a game-only express Circulator directly from Union Station to the stadium.

The N22 expansion makes sense, even if its roundabout route to the stadium, via 8th Street SE, might discourage baseball fans from riding. But the express line is dependent on the reopening of 1st Street SE alongside the Library of Congress’ Madison Building, which has been fortified since 9/11. That’s not gonna happen. And the extension of the 7th Street Circulator, which would also offer an indirect approach to Natsland, seems primarily designed to coerce a few more people onto a route that currently attracts almost no passengers. (At the TOPP event, even a Metro representative allowed that ridership on the 7th Street Circ is “light.”)

Possible supplemental transit strategies include a bicycle “valet” to encourage gamegoers to cycle to the stadium and a water taxi to the area. The latter seems a long shot, however, even if four companies have reportedly expressed interest in a 18-month pilot program. After all, a water taxi could only ferry people from other sites that have mediocre transit access and limited parking, like Georgetown and Old Town Alexandria.

The principal revelation of the TOPP event had nothing to do with transportation, however. The open house was held on the unoccupied top floor of 20 M Street SE, which turned out to be a new office building developed by the Lerner family, who also own the Nats. The 10-story building was appointed with baseball-related art, an outdoor video screen that showed stylized images of the game, and an electronic signboard that welcomed attendees in the name of the Lerners. Inside, each person who entered the session was offered a soft-sided mini-cooler branded with the Nats’ logo.

From the 10th floor, there was an unencumbered vista of the stadium but also a view of the new official plan for Washington: Block after block of bland office cubes, with no public structures, few shops or restaurants, and little public space. And those blocks that haven’t been ceded to private developers will be the province of the security-crazed feds. So enjoy that soft-sided mini-cooler, Mr. and Ms. D.C. It’s all you’re getting.