Legal challenges have once again played havoc with the construction schedule for Maryland’s Purple Line, raising the possibility that the 16-mile light rail system may miss its planned 2022 start-up date according to state transportation officials.

Within days of the project’s August 27 groundbreaking—made possible only after a favorable federal appeals court ruling allowed work to proceed—residents adjacent to the Purple Line filed suit questioning tree-clearing practices by contractors working for Fluor-led Purple Line Transit Partners, which is building the $5.6 billion rail line under a design-build-operate-maintain public-private partnership. Those challenges were denied in mid-September, allowing work to resume. However, outcomes of other pending lawsuits could hamper construction yet again.

Long envisioned as an east-west transportation alternative across the Washington, DC, suburbs between Bethesda and New Carrollton, the Purple Line has progressed in fits and starts due as a result of several lawsuits questioning the project’s environmental impacts. Much of the state- and county-owned right-of-way has long served as a multi-use trail, which is being redesigned to run alongside the new tracks.

Gov. Larry Hogan (R) threatened to drop the project upon taking office in 2014 unless the state’s share of the then-estimated $2.45 billion construction cost could be reduced.

Increased local government contributions, combined with $550 million in savings offered Fluor-led Purple Line Transit Partners, put the Purple Line back on track, only to be stymied again on the eve of its originally scheduled August 2016 groundbreaking by a new lawsuit challenging the accuracy of project’s ridership projections in light of a falloff on the separately operated Metrorail system. State officials are counting on approximately one-quarter of Purple Line riders to come from transfers between the two transit lines at four stations, with a total daily ridership of 74,000 by 2040.