Metro's board of directors is scheduled to vote Thursday on a major rehabilitation plan for the rail system's busiest line.

The plan for the red line would cause frequent delays because trains would share a single track on weekends and on weekday nights after the evening rush.

Weekday track work is currently limited to hours when the system is closed. But Metro officials say that's not very productive because workers have a very short window to set up equipment, work and remove equipment before the system opens in the morning.

Metro capital projects chief David Couch says the maintenance would pause during nights when major events are scheduled.

Metro is planning to do similar work on the orange and green lines in coming years.