 If it's summer, there must be track work somewhere on Metro rail lines. Crews will be installing radio, fiber, and cables during late-night track work this month on Metro's Blue Line. The Blue Line trains will operate from Franconia-Springfield to New Carrollton instead of downtown Largo after 10 p.m. this week and next week. This plan will avoid single tracking, allowing Blue Line trains to run every 15 minutes as normal in the evening.