Riders board one of the final trains to leave Metro Center on a Friday night. (Pouya Dianat/The Washington Post)

The nation’s late-shift workers play critical roles in the food service, medical and manufacturing industries, keeping bars and restaurants humming, caring for hospital patients and ensuring that packages are delivered on time, yet many are shut out of the public transportation options available to their day-shift counterparts, a new study finds.

About 17 percent of workers in large metropolitan areas work late shifts, but because they work in some of the fastest-growing industries, those numbers are expected to increase over the next decade, according to a report commissioned by the American Public Transportation Association. Yet, the economic impact of these workers is already significant: Late-shift workers bring home $28 billion in wages a year and facilitate an estimated $84 billion in sales, the report said.

Even so, public transit agencies face significant challenges when it comes to serving this segment of the population, particularly because many are struggling to provide service during the day, when the majority of riders use public transportation.

“The public conversation around public transportation often focuses on those working the traditional 9 to 5 jobs,” said Paul Skoutelas, APTA president and chief executive. “But this study sheds light on the sometimes forgotten commuter.”

The study argues that offering more transit options for those who work nights and early mornings, can increase retention, reduce absenteeism and boost productivity for businesses at the same time it eases the financial burden on workers. It focuses on options for workers who live in large metropolitan areas — home to roughly 86 percent of the U.S. population.

At midnight, the Dupont Circle Metro station is still crowded with commuters returning home after spending time in clubs, bars and restaurants, or after working late. (Astrid Riecken/For The Washington Post)

This is the first time APTA has looked specifically at the needs of last-shift workers, generally defined as those who begin their shifts between 4 and 6 p.m. The study found that these workers are often less educated and make less money than those who work the day shift; their annual median wage is $30,000, about $5,000 lower than the median wage of daytime employees. Because of the lack of transportation options that match their work schedules, they may spend more of their income on transportation, especially if they drive.

There often are fewer riders late at night, which makes providing service less cost-effective for transit agencies. Adding to that, after years of underinvestment, transit agencies often need the overnight hours for maintenance and repairs — a scenario that is familiar to transit users in the Washington region, who have been dealing with reduced subway service and sometimes no service as Metro struggles to catch up after years of neglect.

In June 2016, Metro imposed a moratorium on late-night closings and early openings when it launched SafeTrack, its year-long maintenance blitz aimed at restoring the system to a “state of good repair.”

Later, despite pleas from late-night workers who said the change made it difficult to get to work and politicians concerned about the economic impact, transit agency officials decided to continue with the reduced service hours. The agency said it needed the extra track time for preventive maintenance and so the system closes at 11:30 p.m. instead of midnight weekdays and at 1 a.m. instead of 3 a.m. on weekends. The shift affected an estimated 2,600 customers who used the system between 11:30 p.m. and midnight.

The agency has tried to fill the gap left by the service cuts. In July, Metro launched a year-long program that subsidizes ride-hail trips for late-night workers in the hospitality, health-care and other service industries.

Under the $1 million program, Metro will pay for up to $3 of an Uber, Lyft or taxi trip for those workers between midnight and 4 a.m., seven days a week.

Detroit has a similar program that gives users $7 toward an Uber or Lyft trip. The program is funded with private dollars.

Although such partnerships may be beneficial, the APTA report said that more study is needed to determine whether they meet late-night workers’ transportation needs.

And some transportation advocates argue that rather than subsidizing Uber and Lyft rides, transit agencies should increase late-night bus or shuttle service.

Other transit agencies have expanded hours to accommodate late-night workers. In Las Vegas, where nearly a quarter of workers start their shifts between 4 p.m. and 6 a.m., the transit agency offers extensive late-night bus service. Thirteen of the region’s 39 bus routes operate 24 hours a day. But the report notes that Las Vegas is unique among cities.

The report acknowledges that not all agencies have the ability — or large enough workforces — to justify more hours of service. But there are other strategies that could work, including offering special late-night service on key routes or partnering with private-sector employers to provide shuttles or van pools.

Most important, Skoutelas said, more policymakers need to realize that late-night workers have transportation needs, too.

“We can’t afford to leave behind one of our fastest-growing populations,” he said.