U.S. Transportation Secretary Anthony Foxx and Los Angeles Mayor Eric Garcetti presided over a groundbreaking Tuesday for the $1.4 billion downtown Regional Connector, a project still facing legal challenges from downtown L.A. property owners.

Metro’s Regional Connector project is a 1.9-mile rail segment designed to link three existing rail lines that converge downtown – the Blue, Gold and Expo lines – so passengers won’t face multiple transfers. It would also add three new downtown subway stations. The project has been on the books for more than 20 years, but only this year received most of its funding.

“With just two miles of added light rail in downtown Los Angeles, it will become possible to offer a one-seat ride across the county,” said Therese McMillan, acting administrator of the Federal Transportation Administration, who also attended the groundbreaking.

Pre-construction work, including utility relocation, started two years ago; in April, Metro awarded a $927 million construction contract to a joint venture of Skanska USA and Taylor Bros. Completion is set for 2020.

But the project is still tied up in court. Several downtown landlords – including Thomas Properties Group Inc. and the Westin Bonaventure Hotel – are opposed to Metro’s “cut-and-cover” construction method, especially along Flower Street. That type of construction involves digging a massive trench for the rail lines, then covering the top, likely impairing traffic along Flower for years.

Landlords want Metro to instead do the construction with underground tunnel boring machines; Metro has said that would be difficult and more expensive given the area’s soil conditions. The landlords have filed two lawsuits, one in federal court and one in state court.

In June, landlords won a partial victory when a federal court ruled that Metro did not adequately address above-ground traffic impacts of its “cut-and-cover” construction method. But last week, a state court ruled that Metro did adequately consider the above-ground impacts. Appeals are possible in both cases, so the legal battle is expected to continue.