The Mass Transit Administration (MTA) will test trains tomorrow on the remaining three-mile section of the state's Central Light Rail Line, from Linthicum to Glen Burnie.
Stations will open in Ferndale and Cromwell Station/Glen Burnie in mid-July.
MTA officials began supplying electricity to the overhead catenary wires over the weekend and plan to tow a train down the line tomorrow to test the height from the top of the train to the wires.
Test trains, used to check signals, switches and power systems, will begin running day and night most likely by midweek, said Dianna Rosborough, MTA spokeswoman.
"Light rail trains are extremely quiet, and area residents should be alert that trains will be moving in both directions along the three-mile segment," said Larry Engleman, director of safety and police for the MTA.
He advised crossing only at designated crosswalks and urged parents not to let children play on or near the tracks.
The Cromwell Station stop, at Dorsey Road and Baltimore-Annapolis Boulevard, has the system's second-largest parking lot, with 780 spaces.
Since three miles of the line from Patapsco Avenue to Linthicum opened in April, the parking lots have remained about two-thirds full, Ms. Rosborough said.