Commuters exit the L'Enfant Plaza Metro station on Tuesday morning. (Marlon Correa/The Washington Post)

What Washington area commuters hoped would be a silver lining of a federal government shutdown — a less-frenzied rush hour — didn’t materialize for many Wednesday, leaving some to ask: If hundreds of thousands of federal workers stayed home, why was my commute still so bad?

“It was the volume that shocked me,” said Jean Stoner, who had expected a breeze of a drive between her Arlington County home and her office at the Health Information Services division of 3M, in Bethesda. Eastbound Route 50 and roads through Rosslyn were “incredibly slow and congested,” she said.

“I was yelling at the other cars, ‘Aren’t you furloughed today?’ ” Stoner said with a laugh.

Some Metrorail and bus riders, on the other hand, found nearly empty buses and vacant seats on trains that are usually standing-room only. About 56,000 fewer people than usual — enough to fill 60 trains — rode Metro between 5 a.m. and 10 a.m., Metro said. That amounted to a 20 percent drop in ridership from the previous Wednesday morning.

One rider tweeted a photo of an empty Metrorail car with the headline “Furlough train.” Another wrote: “Ghost train/ snow day feel to the Metro this morning.”

Metro said it will continue its regular weekday schedule but will limit all trains to six cars, instead of the typical mix of six- and eight-car trains. Some Metro leaders have said they’re concerned about lost passenger revenue if the shutdown is prolonged. Fare revenue for fiscal 2013 was $20.3 million less than expected. Although Metro receives some federal money, it is mostly funded by the District, Maryland and Virginia.

MARC officials said its trains were running 75 percent to 90 percent of regular daily passenger loads and that they did not expect the shutdown to have a “big impact” on revenue. They said they planned to keep trains on the current schedule through this week and reassess Monday whether to cut back service levels.

But there was no shortage of vehicles jamming area roads Wednesday. So what happened?

The short answer: Federal workers telecommute, carpool and take transit in disproportionate numbers, local commuting experts said. That means they don’t take up as much room on the road as their numbers might indicate.

Moreover, experts say, the Washington area’s traffic volumes are so crushing that even taking thousands of people out of the equation leaves enough traffic that everyday occurrences — fender benders, debris in the road — still create quick backups that can take hours to dissipate.

Meanwhile, some carpools partially made up of federal workers likely have broken up, leaving the remaining people to drive in individual vehicles, experts say.

Another leading theory: Some people who prefer to drive but usually don’t jumped at the notion of open roads.

“Some people who didn’t drive before may be thinking, ‘Ooh! I can drive now!’ ” said Ronald Kirby, transportation planning director for the Metropolitan Washington Council of Governments.

Andy Ventura of Bethesda said the shutdown-related closure of part of Beach Drive in Northwest Washington turned his 35-minute drive to his software development job downtown into an hour and 10 minutes. Inbound Connecticut Avenue was stop and go.

“I didn’t expect it to be great,” Ventura said, “but it’s never been this bad.”

Ventura, who said he’s considering switching to Metro, had a Facebook message for Capitol Hill: “Thanks, Congress, for messing up my commute to my job, where I actually do my job, as opposed to you.”

Transportation experts say one day hardly makes a trend, and it will take at least a week to fully gauge the shutdown’s impact on travel patterns. By then, more tourists will have canceled Washington vacations and more federal contractors might be out of work.

Metro is likely to continue to feel the biggest impact, Kirby said, because so many federal workers take transit, thanks to hefty federal transit subsidies and many federal agencies being downtown and near Metro stations. A recent COG commuter survey showed that 32 percent of federal workers took trains or buses, compared to 13 percent in the private sector and 19 percent across the entire region. About half of federal workers — 52 percent — said they drove alone to work, compared to 73 percent of private-sector employees.

Some Metro lines and roads are likely to remain plenty full, experts say, because the growth of other industries, such as hospitality, have left more private-sector employees who still need to get to work.

“Federal employees are a big clump of folks, but they’re only a share of what goes on in this town,” said Alan E. Pisarski, a Northern Virginia-based transportation expert and author of “Commuting in America.” “The feds are big but not a dominant factor anymore in the scheme of the metropolitan area.”

Valerie Weeks, a morning operator for a regional traffic monitoring system, said traffic volumes overall appeared “a little lighter” than usual. Weeks, who works for the Metropolitan Area Transportation Operations Coordination program in College Park, said she noticed the biggest difference at regular chokepoints inside the Capital Beltway, such as the inbound 14th Street bridge. By 8 a.m., those areas glowed green on her computerized maps — representing free-flowing traffic — rather than the usual red, signifying a 25-miles-per-hour crawl, she said.

A Virginia Department of Transportation analysis of Northern Virginia highways Wednesday morning also showed more free-flowing green — and less orange and red — on eastbound Interstate 66 and northbound Interstate 95 and Interstate 395, compared with the previous Wednesday.

Linda Cahaelen of the District said her Metrobus, which is usually packed, carried three passengers Wednesday morning. When she boarded the Red Line at Metro Center, she said, she found empty seats.

But her delight was tempered. Cahaelen said she works for a federal agency, which she declined to name. She said it’s still funded but could be shut down in a few days. “It’s a nice commute,” Cahaelen said, “but the thing is, you know why it’s like that, and it’s not just a light day. It’s sad. It’s a very terrible situation.”

Luz Lazo contributed to this report.