Metro has hired a consultant to build ridership models that take into account the impact of ride-hailing services Uber and Lyft as part of the transit agency’s effort to determine where its riders have gone and how to win them back.

Uber and Lyft have billed themselves as complements to transit, but in Metro’s case, gains by the apps have coincided with service declines that have sent tens of thousands of commuters seeking more reliable alternatives.

Metro spokeswoman Sherri Ly said the consulting firm, VHB, was hired to “build a platform” to create a forecasting and modeling tool that will help Metro find ways to “stabilize” its ridership and grow its numbers. The agency also is concerned about the advent of driverless vehicles, which could lure even more customers away from transit and back onto the roads.

Metro said the analysis is due by next summer. The agency declined to specify the cost or make anyone available to discuss the effect of ride-hailing services on ridership.

Other big-city transit systems are struggling with the same issues.

For example, Chicago Mayor Rahm Emanuel (D) this fall cited the toll that ride-hailing has taken on mass transit in his city when he successfully pushed for a 15-cent fee increase on Uber and Lyft trips to support modernization efforts for the Chicago Transit Authority.

District officials are not likely to make a similar move — at least not immediately. At a recent announcement for a new support hub for Uber’s growing network of drivers in the region, D.C. Mayor Muriel E. Bowser (D) mulled the swift growth of Uber and Lyft and how it might factor into Metro’s precipitous ridership decline. Her conclusion: Metro has itself to blame for its ridership problems.

“There are a lot of things that are cutting into Metro ridership,” Bowser said in response to a reporter’s question. “I would put first among them the year-long SafeTrack [maintenance] program, and also the cutting back of hours at Metro. So I wouldn’t start with Uber, I would start with Metro itself.”

Metro’s rail ridership is down to 615,000 average weekday trips — about 135,000 fewer than 2009 peaks. Weekday bus ridership is down 8 percent year-over-year, according to the latest statistics.

Numerous factors are responsible, according to Metro: the rise of telework, a shrinking of the federal workforce, lower gasoline costs, and performance and reliability problems, which alone are blamed for about 30 percent of the losses.

Metro’s limited understanding of the impact of ride-hailing services was demonstrated at a recent staff presentation to the board: On a chart plotting ridership loss factors on a spectrum from “limited insight” to “high insight,” the growth of ride-hailing was among the issues least understood. It was labeled as “not within our control.”

Uber says it has 1.9 million active riders in the Washington region, and the number of its drivers is 42,000, up from 30,000 in 2016, according to company statistics. Lyft, which launched in the District in 2013, nearly tripled its rides in the region between 2015 and 2016, according to company data. And in the first six months of this year, amid fallout from various Uber scandals, Lyft provided more rides than it had over the entire previous year — both in the District and nationally, according to a company spokesman. The company did not provide numbers.

The District also quickly became the fastest-growing market for another ride-share service, Via, after it launched here in 2016, and ridership grew by a factor of seven in 2017, according to a company spokeswoman.

SafeTrack, Metro’s year-long renewal program, brought an influx of new riders to each of the apps — which offered deeply discounted fares targeting D.C. commuters. At points during the program, Uber offered $3 pooled rides within the District, and Lyft discounted trips up to 75 percent.

Consultant Hubert Horan, who has studied both Uber and Metro, said in an email interview: “Uber fares and service levels were heavily (and unsustainably) subsidized while the cost of competing modes (including transit) was increasing, with service cutbacks and worsening reliability.”

While some question the apps’ long-term economic viability, data shows that for the time being, ride-hailing is filling a transit vacuum in the Washington region. Uber is busiest late Friday and Saturday nights, when Metro’s truncated hours close the system at 1 a.m., according to an Uber spokesman.

Uber contends that it is not a Metro competitor, calling the transit system the “backbone” of the region’s transportation network. And the company often points to a 2016 American Public Transportation Association study that found ride-hailing customers were more likely to be frequent transit users.

Still, data compiled from several studies in multiple cities suggests that among customers hailing rides instead of using another form of transportation, 15 percent to 30 percent would have used mass transit if not for the apps.

“If they were complementary to transit, then transit should have grown really dramatically, on par with Uber and Lyft,” said Regina Clewlow, a transportation researcher who led a study that looked at ride-hailing’s impact on mass transit for the University of California at Davis’s Institute of Transportation Studies. “Obviously they haven’t — they’ve gone in the opposite direction.”

Asked why they would take Uber and Lyft instead of transit, customers’ most common answer was that transit “services are too slow,” according to the October study from UC Davis. Researchers found that after adopting ride-hailing — like a quarter or more of residents in major cities — Americans use transit 6 percent less.

Buses, often the preferred mode for trips between two points in a city, suffer the most, with a 6 percent reduction in use from ride-hailing customers. ­Urban rail trips, like Metro’s, fall 3 percent, while commuter rail use actually increases slightly, according to UC Davis researchers.

Another study found that while ride-hailing was initially seen as a replacement for taxis, today “most [ride-hailing] customers are coming from transit, walking and biking.” The study’s author said ride-hailing was likely a factor in ridership losses in New York, where subway ridership fell last year for the first time since 2009.

“What Uber and [its competitors] have done is they’ve shone a bright light on deficiencies and other gaps in the public transportation systems in New York, D.C., Chicago,” said Bruce Schaller, a consultant and former deputy commissioner for traffic and planning in New York, who led the “Unsustainable?” study on the growth of ride-hailing services there.

“What’s happened is that there’s now consequences if public transit isn’t up to snuff,” he said. “Before, people just had to tolerate it.” The answer, in his view, is to “improve service, expand capacity, [provide] better customer information.”

Emily Castor Warren, Lyft’s senior director of transportation policy, said the losses by transit agencies such as Metro are largely on the bus side — a conclusion consistent with the work of Clewlow, author of the UC Davis study — while systemwide decreases can be found during off-peak hours and weekends when service is reduced. Those are often the most expensive times for transit agencies to run service.

“If I were them, I would be looking to provide that service in different ways,” Warren said.

Researchers warn that if the trend continues and companies such as Uber and Lyft can cut costs by rolling out autonomous vehicles — eliminating the need to pay drivers — the effects could be devastating for local transportation networks.

“You could have a steady flow turn into an avalanche of people switching from transit to these vehicles as they get cheaper and cheaper,” Schaller said. “What will happen is it’ll be easy to get a ride and then you’ll sit in traffic. So you’ll minimize your wait time and you’ll maximize your trip time.”

Though the rollout of fully ­autonomous vehicles for consumers is years away, Metro officials have expressed concerns about the prospect. At a recent Metro board meeting, board member David Horner urged innovation in the agency’s planning.

“The rise of autonomous vehicles over the next decades could be devastating unless we get our capital programming right,” he said. “We can’t be Sears, Roebuck in the era of Amazon.”