What's the latest on the Purple Line as trains are tested in Maryland?

Ten years after the Maryland Department of Transportation signed a $5.6 billion contract to design and build the Purple Line — a 16.2-mile light rail system in Washington DC's suburbs — construction remains ongoing, but there are signs the end is near.

The Purple Line, which broke ground in August 2017, was 89% completed as of late March, and test runs are now underway at some sections of the 21-station line that connects Bethesda to New Carrollton.

Here's what to know about the long-awaited Purple Line.

Initially approved in 2015, completion of the Purple Line has faced several delays due to "challenges we are facing on the project," according to the Maryland Transit Administration.

Delays have been caused by contractor disputes, utility relocation challenges and supply chain issues, pushing the expected opening to winter 2027, but an exact date is unclear.

"Construction will still be in full swing this spring, but every day we progress closer to solely focusing onvehicle testing and systems integration, which will be our focus throughout the remainder of 2026 and 2027," Ray Briggs II, Purple Line senior project director for the MTA, said in March.

Briggs said as some areas of the project finish completion, there will soon be "more new landscaping than orange work zone cones."

The Purple Line will have 10 stations in Montgomery County and 11 in Prince George's County, connecting crucial parts of Maryland's DC suburbs.

It will begin on one side in Bethesda — northwest of DC — and will pass through communities including Chevy Chase, Silver Spring, Takoma, College Park, Riverdale Park and Hyattsville. It will end in New Carrolton — northeast of DC.

The Purple Line connects to four Metrorail stations on three lines: the Red Line at Bethesda and Silver Spring, the Green Line at College Park-UMD and the Orange Line at New Carrollton.

The project is expected to reduce congestion on the Capital Beltway and Metro, providing faster connections across Maryland suburbs without traveling into DC.

Officials have said more than 60,000 daily riders are expected to ride the Purple Line.

On March 25, officials announced the "Purple Line is in motion" with tests underway near the University of Maryland campus.

Testing will occur from 10 p.m. to 6 a.m. "from the College Park-UMD Station onto Campus Drive, through Rossborough Lane, across Route 1, and through campus along Campus Drive ending at the Adelphi Road-UMGC-UMD station."

"We're closer than you think," officials said as they showed testing in action.

The $5.6 billion project is being paid for through a mix of federal, state and private money.

The U.S. Federal Transit Administration announced in 2017 a $900 million federal grant agreement, and additional federal support has come through low-interest TIFIA loans, including one for $1.76 billion.

The Maryland Department of Transportation and state Transportation Trust Fund are also providing funding, along with various private partners.

This article originally appeared on USA TODAY: When will the Purple Line be completed in Maryland? What to know