Maryland broke ground on the Purple Line Monday, 31 years after it was first proposed.

At a ceremonial event Monday, Transportation Secretary Elaine Chao signed a funding agreement for the 16-mile light rail line, which will run from New Carrollton to Bethesda, with stops in Riverdale Park, the M Square research park, the College Park Metro station, the University of Maryland and Langley Park, among other places.

The ceremony marked the latest reversal for the Purple Line, which has faced just about every setback a U.S. transit project can face: A wealthy suburb that sued to keep the line from passing through, a last-minute decision from a federal judge that delayed construction, the election of a governor who was skeptical of the project and the election of a president who was broadly skeptical of mass transit.

The project’s saving grace may have been the public-private partnership being used to build it, which was a selling point for Chao at the event, especially as the Trump Administration eyes similar partnerships as part of its own infrastructure plan.

“We do not have the money for every project that needs to be done in this country,” she said at the groundbreaking.

The Purple Line is not in the clear yet. A federal appeals court will still hear from opponents who hope to stop it, but the groundbreaking marked the moment the project was past its most serious hurdles.