Metro disruptions — both the planned ones on weekends and the unplanned ones during the workweek — often mystify riders. And recently, the transit authority has given them a lot to puzzle over.

Dear Dr. Gridlock:

On Thursday, May 30, from around 5:30 to 6 p.m., at the Foggy Bottom Metro station, I saw two trains headed to Vienna that had at least one darkened, empty car. The rest of the cars were full.

If Metro can routinely run trains with one or more cars out of service, why can’t they do this when the train has a door problem?

It seems such a waste for both the passengers and Metro to have to off-load an entire train for issues with a single car’s doors.

— Diane Peterson, Fairfax

It is possible to isolate a problem car, depending on what the problem is, where it’s identified and when. When a train suddenly develops a door problem in the middle of a line at rush hour, it may be better for a majority of the line’s riders to isolate the whole train by taking it out of service.

“It’s about minimizing delays for the greatest number of passengers,” Metro spokesman Dan Stessel said. The time spent analyzing a door problem and then closing off that car creates a big gap in front of the stalled train while other trains bunch up behind it.

Unloading is an inconvenience to the riders. But the impact on crowding throughout the line is less drastic if you “keep the parade moving,” Stessel said.

The operator gets the passengers off the train, then overrides the safety system that would otherwise prevent it from moving with a door problem. As the troubled train moves down the line, technicians can board, try to figure out what’s wrong and, perhaps, get it back in service.

Weekend schedules

Policies and plans can go awry, and Washington Nationals and Capitals fans testified to that when they described the chaotic scene at Ballston station on Friday night, May 10, after a scheduled maintenance disruption began on the Orange Line.

“We dropped the ball,” Stessel said. There weren’t enough buses at Ballston to handle the returning Nats fans.

He said Metro managers now have a weekly meeting to discuss how the upcoming weekend’s track work schedule will interact with events.

That doesn’t mean canceling track work. Stessel is talking about identifying stations where riders could benefit from better communications about the scheduled disruptions and more staff support to get them to their destinations. The meeting should also ensure that bus planners have lined up enough service to handle the crowds.

Weekend events draw many people who ride Metro only occasionally. Unlike commuters, they don’t see service announcements posted in stations. Stessel said Metro hopes to get track work information and travel tips to these people through event sponsors.

For example, he said, Metro will ask the Nationals to help distribute information about track work that could affect fans via e-mails and links on the team Web site. Stessel said Metro was trying to get word of this weekend’s track work to the thousands of people participating in Capital Pride events. I see Metro service tips on the Capital Pride Web site, at

But here’s some extra information for Sunday’s Capital Pride Street Festival, which runs from noon to 9 p.m. on Pennsylvania Avenue NW: Downtown stations nearest to the celebration are likely to be very crowded as people head home. Consider walking to a more-distant station, such as L’Enfant Plaza, south of the Mall. All lines have delays for track work. There will be some eight-car trains in the mix, and Metro may occasionally to add a train, but be prepared to wait.

Dr. Gridlock also appears Thursday in Local Living. Comments and questions are welcome and may be used in a column, along with the writer’s name and home community. Write Dr. Gridlock at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or e-mail