Mosaic District's Driverless Relay Shuttle To End Pilot Project On Friday

FAIRFAX, VA — Relay, the autonomous electric shuttle, is scheduled to take its final spin around Merrifield's Mosaic District on Friday. The pilot project designed to test the effectiveness of driverless public transportation will be coming to an end.

John Zarbo, operations section chief with the Fairfax County Department of Transportation, told Patch earlier this month that Relay did not bring in the ridership that planners had anticipated.

"We started right at the heart of COVID," he said. "We started the route Oct. 20, 2020. While we didn't see the ridership we thought we were going to see, we did see significant ridership. We actually had 356 passengers during the duration of the project."

While that may seem like a small number, Zarbo said the primary focus of the project was really to test the autonomous technology.

"We were the first CAV — connected autonomous vehicle — in Virginia that was running on public roads," he said. "We really wanted to see how the vehicle interacted with the public."

When the project began, FCDOT was unsure of how well the Relay would interact with pedestrians, bicyclists and cars. For that reason, the Relay originally traveled back and forth from the Mosaic District to the Dunn Loring Metro Station via Eskridge Road.

Based on an analysis of the initial data, FCDOT decided in December 2022 to expand the route to include District Avenue, to test it in a low-speed, enclosed environment.

"It's a low-speed shuttle and I think it works really well within a low-speed environment," Zarbo said. "Eskridge is 25 miles per hour and people tend to travel a bit more than that on Eskridge. We realized that it really did operate well within the district."

With an average speed of about 10 to 12 miles per hour, Relay followed a prerecorded path, using various sensors to navigate its environment.

"The vehicle had challenges with vegetation issues, trees and shrubs," Zarbo said. "We had to trim along the corridor to make sure when it sensed something that it sensed it not as an object that it would hit. We did not have any accidents, which was great."

Midway through the project, FCDOT conducted a complete upgrade of Relay's hardware and software. After that, it was much better at detecting vegetation.

While technically a driverless vehicle, the Relay shuttle had a safety steward onboard at all times in case an emergency required the vehicle to stop.

Now that the project was coming to an end, Zarbo said that he could see the autonomous technology being successfully implemented on large, self-contained campuses, like at a college, hospital or workplace.

"One of the challenges we also had is even though it's only a mile, we travel the roads owned in various portions throughout that line by VDOT, Fairfax County, then it goes to private property, and then it goes back to Fairfax County, and then it goes to WMATA," he said. "That means anything that we do along that corridor, we have to coordinate with all of those other entities. Even putting up a sign can be a challenge."

The Relay pilot project was conducted through a partnership made up of FCDOT; EDENS, the owners of the Mosaic District; Dominion Energy; Virginia Department of Rail and Public Transportation; Virginia Department of Transportation; Virginia Tech Transportation Institute and George Mason University.

The project was paid for by a $250,000 DPRT grant that included $50,000 in matching funds from Fairfax County. Dominion Energy provided the shuttle and its charging infrastructure.