Metro will ramp up transit service in August, operating at about 70 percent capacity to address an expected increase in ridership driven by the return of federal workers to offices and the possible reopening of District schools.

Metro, which has been operating at historic lows because of the coronavirus pandemic, will add more cars to service Aug. 16, and Metrobus will expand its routes Aug. 23. The increase was previously scheduled as part of Metro’s phased recovery plan, but it is being driven by businesses that have resumed operation and the federal government’s push to get its workforce back into offices.

“We were hearing at the time that a lot of groups were looking at the Labor Day time frame, and I think that’s something we had in our minds [expecting] that was a time when people were coming back to work,” Metro board Chairman Paul C. Smedberg said Monday. “We will see how it goes forward with the recent surges, but so far in our areas, things have been fairly stable. But we have had to stay ahead of the demand in increasing service.”

The seven-day average of coronavirus cases in the greater Washington region has nearly doubled in the past month after falling from an early-summer peak.

Metro has been operating a skeletal bus and rail system over the past four months that until recently included the closure of nearly 30 of the transit system’s 91 stations, shorter operating hours, longer wait times and low ridership numbers the regional transportation agency has never seen before. As recently as Thursday, records show that Metrorail’s passenger trips for the day made up 9 percent of what Metro ran on a similar day before the pandemic. Metrobus showed slightly higher numbers — 32 percent of pre-virus ridership.

Transit officials have said the system is operating at a level that is about a third of normal, partly by design to discourage all but essential riders because of the ease with which the novel coronavirus spreads within closed, confined spaces such as rail cars or buses. The transit system has required rear-door bus boarding that limits operators’ exposure to passengers, while it has made wearing a mask or other face covering mandatory.

For months, Metro-commissioned surveys have shown that the region’s nonessential employers and employees have said they have no plans to go back into offices until at least fall, and Metro created a recovery plan that mirrored the response. The transit agency does not anticipate a return to full service until next spring, when a coronavirus vaccine might be ready.

But late last month, as Maryland, Virginia and the District began lifting business and social restrictions, Metro began to see a trickle of riders consistently returning to the system.

Some of the passenger traffic came from federal workers, whom the White House wants back in offices to help create a sense of life returning to normal — and to potentially boost public confidence. According to Metro’s surveys, of the organizations with more than 40 percent of employees commuting to work now, 34 percent are government agencies, while 8 percent are private businesses.

“Public agencies are summoning employees back to the workplace at a much faster rate than private businesses,” the Metro staff stated in a report. “As conditions improve, jurisdictions will continue to relax stay-at-home policies and additional businesses, schools and child care facilities will reopen. Accordingly, more customers are expected to commute to work or travel for other needs.”

On Aug. 16, Metro will put 81 of its 91 stations back in operation, with others scheduled to reopen around Labor Day. Metrorail will bring back peak-rush-hour service — more trains and shorter, five- to eight-minute waits during weekday commuting hours — for the first time since it was stopped in mid-March. Peak rush-hour service runs weekdays from Metrorail’s opening to 9:30 a.m. and from 3 to 7 p.m.

The rail system will expand its operating hours to 5 a.m. to 11 p.m. weekdays, increasing nighttime service by two hours. Service will open at 7 a.m. Saturdays, an hour earlier than now, and will end at 11 p.m. instead of 9 p.m. And Sunday service, which starts at 8 a.m., will expand its closing time to 11 p.m. from 9 p.m. as well.

Wait times during peak service hours will be shorter than 10 minutes on all lines, while waits during off-peak hours will be 15 minutes or less, Metro said. The agency said the new schedule will be locked in place through the end of the year.

Metrobus on Aug. 23 will start a revised schedule that will start an hour earlier at 4 a.m. and run until midnight, an hour later. The bus system will operate 52 of the system’s busiest lines on normal, pre-pandemic schedules, while 64 will operate at reduced frequencies. Thirty-seven routes will remain closed. Metro estimates that the weekly schedule will bring back 73 percent of pre-pandemic service.

On Saturdays, 53 routes will operate on their old weekend schedules, 30 will run at reduced frequency and 12 will remain closed. The agency said the schedule is 87 percent of what Metrobus ran before March.

Metrobus’s Sunday schedule will be 86 percent of its pre-pandemic Sunday schedule, with 73 lines operating normally and four lines operating at reduced frequency.

Even as Metro is limiting passengers on buses, allowing operators to skip stops if they feel too many people are already aboard, some buses are carrying more passengers than social distancing guidelines would recommend. Metro has tried to decrease crowding by redirecting more buses from routes with few passengers to busier ones, but Smedberg said he hopes an expanded system will help alleviate some of those conditions.

“That’s what we’re hoping, and I’m sure that’s what management is hoping,” he said.

Metro said it will also increase cleaning and disinfecting to coincide with the expected increase in staffing. Contractors will make 35 “proactive recovery disinfecting cleanings” each month at Metro rail yards and bus garages and at other Metro workforce buildings, officials said.

“As this phase may continue for several months and ridership levels and conditions are likely to evolve, staff will continue to monitor ridership and workforce availability and consider more significant service changes if warranted,” Metro said.

Before the pandemic affected the region, Metro was slated to expand late-night Metrorail service to midnight during the week and 2 a.m. on Friday and Saturday nights. But those plans have been suspended until at least spring, because many bars and late-night businesses remain closed.

The transit system said it recognizes that there are still late-night workers who rely on public transportation, and in response the agency said it is doubling an after-hours subsidy program that provides Lyft service to help overnight workers get to and from jobs. From 11 p.m. to 5 a.m. Mondays through Thursdays and from 1 to 7 a.m. Fridays and Saturdays, Metro customers with registered SmarTrip cards will receive a subsidy of $6 per ride, up from $3.

“We know that the system closing times still leave some gaps, particularly for employees whose shifts start or end during the time that Metro service isn’t operating,” Metro spokesman Dan Stessel said. “While the earlier closing times are necessary to undertake the massive cleaning effort that occurs nightly across hundreds of rail cars and buses, Metro is stepping up its support of overnight workers by doubling the subsidy.”

Metro said it remains on track to reopen the Silver Line and all stations west of Ballston, which have been closed since Memorial Day weekend for platform replacements or testing to connect the yet-to-be-opened Silver Line extension to Dulles International Airport. Six stations are scheduled to reopen Aug. 16, while Vienna, Dunn Loring and East Falls Church stations are slated to come back online around Labor Day, Metro said.

One thing not coming back: Metro’s Rush Hour Promise, a money-back guarantee anytime a Metro commute is delayed by 10 minutes or more during peak hours, Metro said. While the federal Cares Act coronavirus relief legislation is helping to fill budget shortfalls, Metro continues to lose money at fare boxes while it braces for subsidy cuts from local governments also struggling because of reduced tax revenue. The transit agency said the guarantee was a cut officials had to make.

“The program was suspended indefinitely as Metro began reducing service to protect public health, and now, given the budget challenges faced by all of our funding jurisdictions, there are no immediate plans to restore the program, as we think about how every dollar is spent,” Stessel said.