Bus riders wait for a bus on 16th Street near U Street in Northwest. (Astrid Riecken/For The Washington Post)

Starting this month, up to 60 buses an hour will zip through a new dedicated bus lane along Rhode Island Avenue, according to the District Department of Transportation, filling a gap in train service prompted by a six-week shutdown of the Red Line’s Brookland and Rhode Island Avenue stations.

The new pop-up lane has transit advocates abuzz about the possibilities for the future of the region’s bus system, which lags behind those in other transit-oriented cities in its lack of an extensive network of bus lanes. Dedicated bus lanes speed travel, making riding the bus amore predictable and reliable experience. Improved service also could help stabilize sagging Metrobus ridership, they say.

To some, DDOT’s experiment hints at larger developments to come — beyond the launch of rush-hour bus lanes along the 16th Street corridor beginning in 2020.

“It shows how quickly you can pop up something like this,” said Stewart Schwartz, executive director of the pro-transit Coalition for Smarter Growth. “Stripe it and paint it, appropriately enforce it.”

The Rhode Island Avenue bus lane will stretch from North Capitol Street to 12th Street NE, and DDOT expects it to carry not only Metro shuttle buses from the shuttered stations to Union Station and downtown, but also the G8 routes and G9 Express buses — normally a rush-hour service — that will run all-day service during the July 21-Sept. 3 shutdown. During the six-week experiment, DDOT says it will gather data to “consider future steps” on bus lanes.

DDOT has not ruled out making the bus lane permanent, though it would not do so immediately in September. For now, it will be the District’s longest and busiest bus lane, the agency says.

“DDOT is actively considering bus priority enhancements up to and including bus lanes in other planning work on major arterials with significant bus routes, too,” DDOT Director Jeff Marootian said.

Schwartz hopes more dedicated lanes are on the way for the District. His group has supported regional bus service initiatives such as Metroway — a bus rapid transit network with dedicated lanes in Arlington and Alexandria — and Richmond Highway Bus Rapid Transit in Fairfax County.

“Hopefully the experience is very successful that we collect a lot of data and then it helps accelerate the study and implementation of dedicated bus lanes and other service enhancements, not just on Rhode Island Avenue but in other corridors as well,” Schwartz said.

Unlike the bright red four-block bus lane along Georgia Avenue, the Rhode Island Avenue bus lane will receive a more modest paint job, DDOT said. There will be posted signage and paint markers, potentially including “Bus Lane” messages on the road.

Marootian said DDOT chose the route along Rhode Island Avenue NE because it will have the highest concentration of buses, compared with the western leg of Rhode Island Avenue where G8 and G9 buses run, but shuttles will not be mixed in. Closer to the Rhode Island Metro station, where the D8 and P6 buses mix with the G9 and shuttles, officials expect as many as 60 buses to squeeze through the corridor per hour. DDOT says the volume of buses dwindles west of 4th Street Northeast, and shuttle buses will turn off the route onto North Capitol Street.

The new project comes as Metro is in the midst of conducting a bus network study, which centers on the role of its bus system and how to best optimize it for riders’ needs. Other cities such as Houston, Baltimore and Richmond have redesigned their bus networks to provide broader coverage than the traditional “hub-and-spoke” systems that typically link residential neighborhoods and central cores. Metro General Manager Paul J. Wiedefeld has said, however, that the Metro study differs because it looks at the business model and role of the existing bus system.

As Metro conducts its study, a coalition of pro-transit and smart growth-oriented policy groups issued a statement of principles outlining what it believes should be the agency’s priorities. The study comes at a critical time for the agency. Average weekday boardings for Metrobus were down more than 10 percent from comparable months last year, according to the agency’s latest quarterly financial report, and the bus ridership declines are “consistent systemwide, across nearly all routes and times of day,” Metro said.

The groups, together known as the “Fund it, Fix it” Coalition, are pushing for more frequent and reliable service and a bevy of initiatives aimed at bolstering efficiency — anchored by dedicated lanes. They say Metro should emphasize service itself before other considerations — and make riding the bus more efficient without sacrificing accessibility.

“Creating a more reliable and frequent bus system must remain at the forefront of the study,” the coalition says in a statement of principles on the study. “In order to achieve a world-class bus system, we must implement improvements like dedicated bus lanes, limited stop service, queue jumps, off-board fare collection, and rush-hour express buses.”

They highlight statistics showing that a dedicated bus lane, for example, has the capacity to ferry three times as many commuters per hour than lanes for solo vehicles.

“No doubt there is great momentum for transit in the region,” Schwartz said. “In addition to fixing Metro, building the Silver Line and building the Purple Line, really the next generation is these bus rapid transit and dedicated bus lane services.”