A Metro worker emerges from the tunnel at Mount Vernon Square during a weekend when trains shared a track around the work zone. (Robert Thomson / The Washington Post)

Starting in July, most of Metrorail’s weekend station shutdowns will not begin until midnight, rather than at 10 p.m. Friday. The total number of major disruptions also will shrink, compared with the second half of 2013.

Under this policy, the planned shutdowns usually will not occur on consecutive weekends anywhere in the system. The exception would be a major project, like a switch replacement, that would require crews to spend a long time in a work zone to finish the job.

Meanwhile, Metro officials also are considering ways of bringing back midday track work on weekdays, the type of work that requires trains to take turns on one open track. But they say it would be different this time, because midday work would be restricted to locations that would have minimal impact on riders.

One example: The work on the test track between College Park and Greenbelt for the new rail cars. “We can single-track between those two stations, while still maintaining the average 12-minute scheduled headway on the Green Line,” Metro spokesman Dan Stessel said. The midday single-tracking would not return to the more heavily traveled core of the rail system, he said.

Metro Deputy General Manager Rob Troup is scheduled to present the revised plan for track work to the Metro board on Thursday during a meeting of the board’s customer service committee.

The change in the weekend work schedule is motivated in part by Metro’s fatigue management program for its employees, Stessel said. But it also reflects the evolution of the five-year rebuilding program’s impact on riders. The number of station shutdowns scheduled during the first half of 2014 was smaller than in previous track work schedules.

In the first half of 2013, for example, Metro closed stations on weekends 22 times. In the first half of 2014, Metro plans included 10 weekend shutdowns. In the schedule for the second half of 2014 that will be presented to the board on Thursday, Metro lists a dozen sections of track that will be shut down on weekends between the start of August and the weekend before Thanksgiving. The major projects are scheduled for the Red, Green and Orange lines. For the second half of 2013, by contrast, Metro listed 30 major projects, affecting all five lines.

Weekend riders know very well that the major track work projects, the kind that split lines and require shuttle buses to bridge the gap, are not the only projects that disrupt service on weekends. More often, Metro will schedule rebuilding projects that close one track segment while leaving the other open for trains to share, the procedure known as single-tracking.

Metro plans dozens of single-tracking operations for all lines on various weekends between the start of July and the end of December.