Richard Rodriguez, center, sits near the back door of a crammed S4 bus in Washington, D.C. The bus passed several stops, and waiting people, because it was at capacity. (Daniel C. Britt/THE WASHINGTON POST)

Metro is being urged to improve its late-night bus service in the District after a report that service-industry workers heading home after 10 p.m. are often left behind by overcrowded buses.

D.C. Council member Muriel Bowser, the city’s representative on the Washington Metropolitan Area Transit Authority’s Board of Directors, said she has asked transit officials to better monitor the bus schedules and add longer buses to the 16th Street routes, the city’s most crowded after 7 p.m.

Tom Downs, a vice chairman on the board, said the overcrowding, unreliable schedules and bus bunching on the routes reflect increasing demand for service systemwide.

“It is not just this corridor in the evening. We are having significant growth in bus ridership, and we need to know where and how and why that is happening, and we need to know how to respond to that over the next couple of years,” Downs said in an interview.

He said he has asked Metro to analyze where ridership is increasing and to hold focus groups. For the 16th Street buses, Downs said that in addition to expanded route monitoring and longer buses, he wants Metro to consider starting some northbound buses at P Street NW.

An article in The Washington Post on Saturday highlighted the commuting struggles of janitors, security guards, busboys and other low-wage workers who travel the 16th Street bus routes between 10 p.m. and midnight.

Although the S2 and S4 buses, which run between the Federal Triangle and Silver Spring Metro stations, are scheduled to run an average of every 71 / 2 minutes, riders often wait more than 30 minutes at a bus stop. At some stops, buses are too crowded to pick up any more passengers.

“This has been a long-standing problem,” said council member Jim Graham (D-Ward 1), who represents Columbia Heights and Mount Pleasant, home to many S2 and S4 riders.

“Those are the people who have every bit of greater claim as anyone else to effective and efficient public transit,” Graham said, adding that he hopes for greater advocacy for bus riders at Metro. “There needs to be a higher priority given to the issues of bus riders.”

The issue is expected to be discussed by the Metro board at a meeting Thursday.

Metro officials said the transit agency is increasing supervision of the night service in the corridor and is working to double the number of extra-long buses on the route to eight in the next two months.

Jack Requa, head of Metro’s bus division, said delays are often unpredictable and can be caused by residual delays from peak-hour service, traffic accidents and events downtown. But he emphasized that buses are scheduled to arrive every 6 to 9 minutes.

“If a bus breaks down, if there is heavy congestion downtown at some period of time, it is not that we are trying to run the buses every 30 minutes,” he said. “We are very sympathetic to what the customers are seeing. We are going to try to keep the buses spaced as well as we can. We are going to try to keep as much seated capacity and standing capacity . . . as we can.”

But he said the bus division needs to work with the resources available without shifting buses away from other lines, where ridership is also up. “We have to be fair to the other routes,” he said. “With additional funding and additional vehicles, we would like to be able to provide more service on this corridor and other corridors.”

Bowser (D-Ward 4), whose district includes 16th Street north of Spring Road NW, said additional monitoring should help address riders’ complaints of unreliable schedules and overcrowding in buses that often come in bunches.

Officials with the Mayor’s Office on Latino Affairs also said they were concerned with what appears to be inadequate services to blue-collar workers, many of them Hispanic, Asian and African American.

“This is a huge concern. This is really big,” said German Vigil, an agency spokesman. “We want Metro to increase capacity.”

Metro officials said the transit agency is working with the D.C. Department of Transportation to review options and funding to implement recommendations in a 2009 16th Street study.

DDOT spokesman John Lisle said that his department has requested ridership data from Metro and that the agency plans to study the issues in the corridor.

On average, Metrobus ridership has increased about 6 percent. The 16th Street line is up by 11 percent.

Commuters who take buses on the 16th Street routes, some of Metro’s busiest, have long complained about unreliable schedules and overcrowding. In 2009, Metro added the S9 express bus to ease backups during the morning and evening rush periods.

“But you are still left with a major problem in the [late] evening,” said Graham, who led the effort for the express line. Now, he said, it is up to the Metro board to come up with a plan.

Riders say all they want is accurate timetables and more buses between 10 p.m. and midnight.

“At this time of the night, we are tired from working all day, and it’s frustrating when you are waiting for a bus and when it finally comes, it just drives by,” Edwin Oxlaj, an 18-year-old restaurant worker, said as he waited for a bus at P and 16th streets.

Katherine Howell, assistant area director for 32BJ of the Service Employees International Union, said some of the local’s 8,000 members, frustrated by their transit travails, are considering a campaign to protest Metro. Most are office cleaners who work at night, and many of them take the bus instead of Metrorail because the bus is more convenient and less expensive.

All they want, Howell said, is “some type of guarantee that the bus is going to be timely and that they will be able to get on the buses and get home to their families.”