Looking at this track map http://www.nycsubway.org/perl/caption.p ... e180th.png, I can see that the only switches onto the Dyre Ave Line are off the local tracks. This means that during rush hours, 5 trains that are running to Dyre Ave need to switch back onto the local track to get onto the correct line, possibly interfering with 2 service which stays on the local track the whole way. The switch just south of Bronx Park East is shown as unused, but 5 trains to Nereid Ave might use it. I don't know.
Do 5 trains to Dyre Ave crossing the WPR local track cause delays in service? Looking at the map, it seems like it would make more sense to switch the 2 to the peak direction express and have it use the switches just south of Bronx Park East to prevent 2 and 5 trains from needing to merge twice. Is there any reason that the MTA hasn't moved to this? Decades ago they changed the 1 to the local and the 3 to express to prevent delays associated with trains switching between local and express at 96th Street.
Do 5 trains to Dyre Ave crossing the WPR local track cause delays in service? Looking at the map, it seems like it would make more sense to switch the 2 to the peak direction express and have it use the switches just south of Bronx Park East to prevent 2 and 5 trains from needing to merge twice. Is there any reason that the MTA hasn't moved to this? Decades ago they changed the 1 to the local and the 3 to express to prevent delays associated with trains switching between local and express at 96th Street.