That’s according to a new analysis from Teralytics, a Zurich-based technology company that examines mobility trends based on bulk data collected from popular mobile carriers. Teralytics says its analysis is based on data from one the “big four” carriers and represents more than a quarter of the region’s population.

The Teralytics analysis shows the trend line of Metro's ridership declines among age ranges, illustrating how extreme the losses have been among millennials. (Teralytics) (Siddiqui, Faiz/Teralytics)

The Teralytics analysis, originally compiled for the advocacy group TransitCenter and expanded for The Washington Post, showed that between April 2016 and April 2018, riders age 29 and under took 21 percent fewer trips on Metro. On weekends, the trend was even worse: Millennials took nearly 40 percent fewer trips when compared with the same month the two years before.

As the data shows, that’s a real problem for Metro because millennials, many of whom have shunned car ownership, make up around one-fifth of transit users and the largest share in the study, according to the authors. (The authors noted the millennial age range was slightly wider than the other categories; And yes, they say, their study adjusts for factors such as the increased likelihood that millennials are carrying a cellphone or commuting to 9-to-5 jobs).

To be sure, rail ridership declined across all age ranges over the two-year period in the study. Metro itself acknowledges that between May 2016 and May 2018, ridership dropped 9.6 percent as the agency embarked on disruptive long-term repairs under SafeTrack, cut its service hours and reduced train frequency across five of six lines.

But the Teralytics data illustrates how dramatic the declines became for a critical segment of the riding population. In April 2018, according to the company’s analysis, millennials were taking more than 30 percent fewer trips than two years before. By contrast, ridership among those 50 to 59 years old was down, but by a figure closer to about 10 percent.

The Teralytics data shows consistent declines in Metro use for all age ranges since April 2016, though ridership has stabilized among older generations. (Siddiqui, Faiz/Teralytics)

“The absolute numbers actually just constantly drop,” said Canay Deniz, chief marketing officer at Teralytics. “Millennials are dropping month by month,” characterizing the consistent dip as, well, “quite crazy.”

Transit ridership is down across the United States in a period coinciding with the decline of urban rapid transit infrastructure and the rise of alternatives such as Uber and Lyft, bike sharing and mobility trends like electric scooters. TransitCenter found rail and bus ridership was down in 31 of 35 large U.S. cities in 2017. But Metro’s losses were more extreme than those of its peer systems amid a period of chronic service and reliability problems that plunged ridership to early 2000s levels.

“I think at the end of the day, after you’ve addressed safety, after you’ve addressed infrastructure, what’s left is service,” Rep. Gerald E. Connolly (D-Va.) said. “And when you ride Metro, that’s the complaint you hear quite frequently.”

Connolly said Metro simply needs to step up and provide a consistent, reliable ride.

“If we’re going to reverse the loss of ridership, that [Metro] study tells you point blank what the real problem is,” he said.

The data firm makes no assumptions about the causes driving the declines. Metro has previously pinpointed factors such as teleworking, a smaller federal workforce and cheaper gas prices. Less clear is the extent to which the service problems have driven riders to alternatives such as Uber and Lyft, whose driver bases have increased by tens of thousands and revenue exploded since 2015, but whose total ridership in the region remains unknown. Uber has claimed to have about 42,000 drivers and 2 million active riders in the Washington region.

Deniz summed up the predicament this way: “The subway knows about subway riders. The bus network knows about bus riders. Ride-sharing companies know about their specific drivers and riders. But none of them know about each other’s riders.”

Nat Bottigheimer, Metro’s former assistant general manager for planning and joint development, said that although the Uber puzzle piece is important, equally necessary is knowing the extent to which people simply are not taking the trips they used to.

"Are people simply making a choice not to travel if they don’t have transit available to them?” he said. “If I have a laptop and I’m mobile . . . I may prefer to be working in a collaborative environment with my partners and I may decide to do that three days a week as opposed to five days a week.”

He said it’s an issue struggling transit agencies have yet to fully grasp.

“You call it telecommuting, at this point I’m not sure people even call it telecommuting anymore,” he said. “They’re just working wherever they are. It would be nice to know how many people are substituting no trip for a transit trip.”

Weekends are another key problem for the agency. Metro says two-thirds of its ridership losses over the past two years have come during off-peak and weekend periods, when the agency typically launches its most disruptive rebuilding and maintenance work, and the system becomes harder to access. For some age ranges, such as the 50-59 and 60-plus groups, weekend ridership actually increased compared with the same period in April 2016. Millennials were a different story.

Those 18 to 29 were taking just 60.5 percent the amount of weekend trips they had taken in April 2016, before SafeTrack, according to the data. The declines illustrated a dramatic trend: While ridership among some age ranges has fluctuated over time, the percentage of millennials riding has consistently decreased.

“We’d be hypothesizing in terms of what the cause of this is,” Deniz cautioned. “There are many, many modes of transportation and the more used to technology you are, the more likely you are to probably test those modes out. . . . I think these new modes of transportation such as bike sharing, ride sharing, all those things — because they’re so tied to technology, they might have a bigger draw for the younger generations.”

“But again it’s a hypothesis.”

Rounding out the analysis was another pointed conclusion that for those attuned to Metro’s weekend service schedule probably isn’t a surprise.