Sometimes the bureaucracy can get as tangled as a traffic snarl on the 14th Street Bridge, even when it's trying to fix the bridge.

Two weeks ago, city road crews began ripping up the approaches to Washington's busiest bridge across the Potomac River. Highway officials figured they had the perfect solution for a detour: send the Virginia commuters home on 15th Street, a parallel route a block away.

Then the confusion started. Federal road crews soon began drilling and chopping away at 15th Street, at times causing midday traffic to back up halfway across the Mall.

"I think it's utterly stupid, but it's the way they always do things in the District of Columbia," declared Egar Levy of Silver Spring as he sat behind the wheel of his sedan one day this week in the 15th Street block between Independance and Maine avenues, waiting for southbound traffic to clear.

Levy was in a single lane of roadway that, as a result of the closures, was expected to handle as much traffic as five lanes on the two streets were carrying before the road work began.

At present, 14th Street with its three southbound lanes is closed to traffic destined for Virginia during most of the day from Monday through Friday, but is being opened to commuters during the afternoon rush hours on those days. The reconstruction of 15th Street requires that its two lanes of normal traffic be squeezed into one.

The decision to shut down the principal approach to the 14th Street Bridge throughout most of the day, and the simultaneous curtailment of a major alternate route, is a result of two government bureaucracies acting independently.

They talked, officials on both sides said, but they weren't always sure what they were saying to each other.

The long-deferred reconstruction of pothole-cratered 14th Street from Independence Avenue south to the bridge is a project of the D.C. Department of Transportation, the city's highway agency. Repaving of the parallel segment of 15th Street is being done by National Capital Parks, the local arm of the National Park Service, which has jurisdiction over the Mall and the adjacent park land. The 15th Street repair area borders on East Potomac Park and the Tidal Basin.

When the D.C. agency began its reconstruction, it formerly posted signs detouring Virginia-bound traffic on 14th Street eastbound onto Independence Avenue to Ninth Street, where it is directed to enter a tunnel leading to the Southwest Freeway and ultimately to the Potomac River bridge. But it also advised motorists in a press release that 15th Street would be available to them and it erected some highway markers with the same message.

"I wasn't aware of [the Park Service's plan to repave 15th Street] until a few days before it happened," said Seward Cross, who is in charge of traffic management for the D.C. government agency. "From their viewpoint, the Park Service has every right to go ahead and resurface that street. . . . We can't condemn 'em -- they have to do their thing."

A spokesman for Manus J. (Jack) Fish, director of National Capital Parks, said the 15th Street repaving -- which ordinarily would have been a minor project attracting little public attention -- had been scheduled since last spring. She said it was delayed until after the summer tourist season, which unwittingly put it into time conflict with the 14th Street job.

That's the bad news. The good news, she said, is that the Park Service job will be completed by mid-November, while the city's reconstruction of 14th Street will last for two years with a variety of changing detours and traffic restrictions scheduled during that period.

Cross, the city traffic chief, said something worse is yet to come for motorists traveling across the 14th Street bridge. Before the reconstruction of the 14th Street approach is completed, he said, the city must begin rebuilding the badly deteriorated payment of the Southwest-Southeast Freeway, an even busier gateway to the bridge.

"I spent two hours today trying to wrestle with that knotty problem," Cross said. "It's nearly impossible to work out something there that will be satisfactory to the motoring public. But we can't defer it."