A Purple Line light rail vehicle is running test laps between the Lyttonsville maintenance facility and Bethesda Station, the most visible sign yet that the 16-mile transit line is approaching service.

Live wire testing began in June 2026 and continues on dedicated Purple Line tracks that do not cross traffic lanes, according to the project's website. Most runs happen between 7 a.m. and 7 p.m., but the site warned that trains could move at any time, day or night, and urged people to stay outside the work zone.

The milestone comes as Maryland Transit Administration (MTA) officials said in late July that the Purple Line is 90% complete, with all 1,187 overhead wire poles installed, Bethesda Magazine reported.

Bethesda station takes shape underground

Below Elm Street, crews are building the cavern and shaft from the bottom up, with waterproofing, concrete pours and excavation authorized in two shifts around the clock, weekdays and weekends. A lobby with fare gates and six elevators will connect riders to the Purple Line platform, Metro Senior Program Manager Jeanne Acquadro told Bethesda Magazine during a Sept. 4 media tour of the station.

Above ground, a 6,000-square-foot mezzanine was erected on the Bethesda Metro platform during the nine-week Red Line shutdown that ran through Sept. 6, MoCo Show reported. The structure, built with 60 tons of steel and 220 cubic yards of concrete, will eventually link Metro riders to the Purple Line. Work on the mezzanine will continue behind protective barriers for about 18 months, with no additional station closures needed.

Acquadro said during the Sept. 4 tour that she does not foresee additional outages, calling the completion of shutdown work "a big win for us."

Detours and construction continue

Pedestrian access between Wisconsin Avenue and Elm Street remains closed. The detour routes walkers to the Wisconsin Avenue crossings at Elm Street and Waverly Street, then west on Hampden Lane to Woodmont Avenue and onto Elm Street.

Elsewhere along the corridor, crews are working on the Jones Mill Road underpass, including utility relocations and retaining wall construction, through fall 2026. Construction of the Capital Crescent Trail between Elm Street Park and Rock Creek Park also continues on the same timeline. Work at the Connecticut Avenue station, including utility installations and retaining wall construction, is ongoing.

Opening timeline still uncertain

The Purple Line's contract calls for service to begin Dec. 30, 2027. But a March 2026 schedule update from concessionaire Purple Line Transit Partners projected a 78-day delay, pushing the start to March 17, 2028, according to a June update from State Delegate Marc Korman. No source published after June 2026 has revised that projection.

In a June MTA progress report cited by Korman, the agency described the "Major Construction Complete" milestone as the point when end-to-end system testing can begin. After that, remaining work is limited mainly to the Bethesda Metro connection and final adjustments.

Residents can sign up for construction alerts at purplelinemd.com/sign-up.