Metrorail riders exit the NoMa-Gallaudet Station as shuttle buses fill the gap between NoMa and Ft. Totten on Monday. (J. Lawler Duggan/For The Washington Post)

Today is the first weekday of what is likely to be Metro’s most challenging SafeTrack project — a 25-day shutdown on a segment of the Red Line affecting about 200,000 peak trips daily on its oldest and busiest line.

No trains are running between Fort Totten and NoMa stations and the Brookland and Rhode Island Avenue stations are closed. The Rhode Island Avenue Metro garage also is closed. SafeTrack repairs on the Red Line started over the weekend but the real test started today on the first day of the work week.

There were some crowds at stations and on trains as well as delays on the Red and Green lines. But there were no reports of any major problems on the transit system in the height of the morning rush hour. There were big delays on Metro shuttle buses as some commuters said it took them up to an hour to ride from Fort Totten to NoMa.

On area roadways, there were two significant crashes in the morning commute — one on the southbound side of Interstate 295 and another on the Southeast Freeway at 6th Street — but it was not immediately clear if any of that was related to more cars being on the road as a result of the surge.

One positive, experts said, is that Monday is typically a day that those with flexible schedules are more likely to telecommute. And, during these early days of the project, commuters will test a variety of options to see what works best.

“It’s three weeks of the surge,” said Sam Zimbabwe, a senior planner with the District’s Department of Transportation. “There will definitely be some adjustments over the course of those three weeks.”

This “safety surge” is the 10th of 15 Metro plans to roll out. The shutdown impacts roughly 200,000 trips daily, Metro said.

For many Metro riders, the partial shutdown of the Red Line caused frustrations not only for those on that line, but also for those on the Green Line, which was promoted by officials as an alternative way to get around.

“Oh come on,” said Theresa Lewis, 49, a federal government attorney as she missed her normal 7:30 a.m. Green Line train to L’Enfant Plaza because of crowding Fort Totten. “This is not gonna work.” She said Metro should be running all eight-car trains.

Even with warnings, especially over the last week, several Metro riders were caught off guard and surprised at the changes in their Monday morning commute.

At the Bethesda Metro station, there were repeated announcements warning riders about the latest surge and to expect “extended delays and crowded platforms.”

Oksana Elgamal, 29, got on a Red Line train at Silver Spring at 6:20 a.m. and had hoped to get to Union Station about 20 minutes later. But she was surprised when the train operator emptied the train at Fort Totten.

“These repairs always catch people by surprise,” she said.

By 6:40 a.m., as she waited for a Green Line train to take her to Gallery Place so she could switch back to the Red Line, she got impatient.

“I just wish they could fix it quicker,” she said.

The work on Metro’s Red Line comes as a major commuter road — Beach Drive in Northwest Washington — is also shut down for work. Transportation officials are worried that large numbers of Red Line users will return to their cars, adding to traffic congestion in the same area.

On Monday morning, traffic was heavy along stretches of Connecticut Avenue, which many drivers are using as an alternative Beach Drive, but there were no major incidents.

This surge also marks the first in which major Red Line work is being done while school is in session.

A series of robo-calls from D.C. Public Schools reminded students and caregivers to set their alarms earlier than normal to deal with the Red Line closures. Several schools, including Wilson High School, McKinley Tech and KIPP DC College Preparatory are among those that are likely to be impacted.

Although commuters were advised to find other routes, many decided to try their normal rides.

Andrew Wachholz, who was headed to Gallery Place-Chinatown from Glenmont said his inbound train seemed to slightly less crowded than normal but not by much.

“I think people are trying it, would be my guess,” he said.

Even at Gallery Place station, which is a key transfer point between the Red and Green lines, it was a relatively placid scene at the height of the morning commute. Platforms were crowded, but trains arrived frequently. Metro staff wore purple vests and carried bullhorns to help lost-looking riders.

It was a similar scene at NoMa, where a Metro employee guided riders and said he was relieved there had been no major disruptions.

“So far, so good. The trains have been coming regularly, things are looking good,” he said, as he held up crossed fingers on his right hand. “Let’s hope it stays that way.”

Metro provided some free shuttle buses along parts of the Red Line, but rides were taking much longer than normal.

“I thought the shuttle buses weren’t going to make that much of a difference. I thought it was going to be pretty smooth,” said Chelsie Pope, 27, who lives near Rhode Island Avenue Metro. Her normal 30-minute commute from Rhode Island to NoMa took an hour on a shuttle bus.

“I didn’t know it was going to take that long,” she said. “I guess they can’t help the traffic.”

Metro added buses along some routes, including the 80, which runs from Fort Totten to Union Station to the Kennedy Center, and the P6, which goes from the Rhode Island Avenue stop through downtown Washington and to Anacostia.

There also are extra buses on Metro’s L2 bus line. That runs along the western part of the Red Line. And there are more buses on the S9 route, which runs between Silver Spring, through Columbia Heights and to downtown Washington.

The D.C. Circulator bus to help Red Line riders. And Capital Bikeshare is offering special rates for non-members.

Transportation officials advised that driving solo should be a last option. On Monday, they were using traffic cams, Waze and Google Maps to analyze the morning choices of thousands of Washington area commuters, looking for clues about whether their weeks of urgent messaging – Walk! Time shift! Take other transit! Please fill automobiles with more than one human being! – was actually working.

Joe Mueller, who rides Metro from Friendship Heights to Dupont Circle, said he would see how things went Monday and then adjust his work schedule if needed.

“If it gets crowded I can shift my hours,” he said. “I can go to work early and leave late to avoid the rush hour.”

One of the more crowded parts of the Red Line on Monday morning was along the shuttle bus route from the Rhode Island to NoMa station as many of the Metro SafeTrack workers were switching shifts.

This project is ­addressing a critical and complex interlocking that lies along one of the oldest stretches of tracks in the system — and it’s a part of the rail network that has long been ­avoided because of the logistical ­difficulties involved in conducting maintenance.

 Lori Aratani, Mike Laris, Luz Lazo, Martine Powers, Faiz Siddiqui and Robert Thomson contributed to this report.