A double crossover, a juncture where trains change tracks, outside Rhode Island Avenue station. Metro will replace the crossover during its 10th SafeTrack surge, a rail service shutdown from NoMa to Fort Totten that begins Saturday and lasts through Nov. 22. (WMATA photo by Larry Levine)

Red Line riders, who flirted with SafeTrack single-tracking for three weeks in August, are in for a real challenge: The next surge, which begins Saturday, will shut down service along a critical corridor of Metro’s busiest line, the biggest test so far in the yearlong repair program.

Surge No. 10 will suspend service between NoMa-Gallaudet and Fort Totten stations, disrupting an estimated 200,000 daily rush-hour trips for 25 days. Officials say it will snarl travel from end-to-end, shuttering two stations in Northeast for nearly a month and drastically reducing service elsewhere on the Red Line.

Officials warned Wednesday that the surge’s impact will ripple throughout the line — not just in the vicinity of the repairs, which continue through Nov. 22.

“The shutdown will result in severe service reductions that impact the entire Red Line, from one end to the other,” Metro General Manager Paul J. Wiedefeld said Wednesday. “Whenever possible, we need Red Line customers with other options to consider telecommuting, traveling off-peak and then also using bus alternatives.”

At a news conference Wednesday, officials from the District, Montgomery County and Metro unveiled plans for moving tens of thousands of affected commuters through the surge, which will close the Rhode Island Avenue and Brookland stations, limiting service on both ends of the line.

The year-long Metrorail rehabilitation plan includes 15 projects that will require the longest stretches of single-tracking and station shutdowns.

Metro will bolster bus service on four popular commuter arteries, the D.C. Circulator is opening an hour earlier on three routes, and the city will implement traffic patterns aimed at easing congestion. In Montgomery County, shuttle bus service will be offered and a limited number of round-trip MARC tickets will be distributed to encourage commuter rail as an alternative.

Officials warned of massive service reductions: On the western end of the Red Line, rush-hour train arrivals will be reduced 50 percent, with service every six minutes. On the eastern end, where trains will terminate at Fort Totten, service into downtown will be cut by more than two-thirds, with trains arriving only every 10 minutes. Metro officials advised riders to use the Green and Yellow lines as alternatives into D.C. — and, if possible, to avoid using the skeletal Red Line service to get there.

Metro said it will add more eight-car trains to relieve crowding on the Red and Green lines. But, Wiedefeld said, “extreme crowding” will not be limited to the area around the surge, and the additional eight-car trains “cannot handle all the traffic that we anticipate.”

While affected commuters are urged to avoid the Red Line if possible, officials also are discouraging them from driving solo, fearing it will lead to traffic gridlock.

Officials note that the surge is happening in the midst of the Beach Drive rehabilitation. That project, being conducted by the National Park Service, has closed portions of the busy thoroughfare, limiting its potential as an alternative.

“The best-case scenario is that people plan ahead, make a plan, avoid rush-hour travel if they are driving and find a bus route,” D.C. Mayor Muriel E. Bowser (D) said after the news conference. “We think that many people will be able to find a one-seat ride, but they have to look for alternatives.”

The District Department of Transportation touted carpooling and Capital Bikeshare as alternatives; the program enacted $2 single-trip bike rides for SafeTrack, and the District will offer bike corral service at Union Station on weekday afternoons.

“I’d like to reinforce the importance of Red Line riders developing a Plan A and Plan B,” DDOT Director Leif A. Dormsjo said. “Driving yourself in your own car should be your Plan C.”

Metro’s agenda for the dilapidated stretch of track, a portion of which is the oldest in the system, involves replacing a degraded double crossover between the Rhode Island Avenue and Brookland stations; replacing two switches near Fort Totten station; rehabilitating six other switches leading to the Brentwood rail yard; performing structural repairs at Rhode Island Avenue station, where concrete spalling created structural concerns earlier this year; and making cable replacements mandated by the National Transportation Safety Board.

Wiedefeld said the task list has grown and evolved as SafeTrack has uncovered further problems and after a July 29 derailment raised an alarm about the conditions of Metro’s crossovers, where trains switch tracks.

“There are six switches that we’re dealing with, a number of interlockings. It’s just the complexity of it,” Wiedefeld said. “We can’t wait to get in to do this work any longer. And it would take so many more months, if not years, to get in to do it if we were just piecemealing it.”

Metro will operate shuttle service between NoMa and Fort Totten during the repairs, but as in past surges, officials said commuters shouldn’t rely on the buses to commute.

“This will only help the riders close to those stations connecting to the rail system,” Wiedefeld said. “It cannot backfill moving all the traffic that normally would ride on the Red Line.”

To accommodate for the lack of trains, Metro will bolster bus service on the 80, L2, P6, and S9 routes, which ferry commuters from Fort Totten, Van Ness, Rhode Island Avenue and Silver Spring into downtown. On those four routes, Metro will float 21 additional buses into service — placing them “where they can do the greatest good” — adding 140 trips throughout the day and providing capacity for about 8,400 more riders than usual.

On the Circulator, service has been expanded to begin at 6 a.m. on three routes: Georgetown to Union Station, Woodley Park through McPherson Square, and Dupont Circle through Rosslyn.

In Montgomery County, free Ride On “Red Line Shuttles” will bounce between Silver Spring, Takoma and Fort Totten stations every 10 minutes during the morning and afternoon rush hour periods, beginning at 5:30 a.m. and 2:30 p.m. weekdays. In addition, the county plans to distribute a limited number of free round-trip MARC tickets at Silver Spring and Rockville Metro stations through Friday to tout the commuter rail service as an alternative.

“Commuters should expect Surge 10 to cause major, major disruptions and delays,” Montgomery Transportation Director Al Roshdieh said.

Dormsjo warned of the impact the surge could have on area roads. As with past surges, he said commuters will adjust to new travel patterns after a few days, but he pleaded with drivers not to get behind the wheel in the meantime.

“We expect the first several days of the surge to be the ones that contribute the most congestion to our roadway system, as people sort through their commuting options and patterns,” he said. “For those of you who can avoid the roads, please do.”