Unused Express tracks

fordhamkid7721 wrote:the part from the old LIRR line to the interlocking before North Channel Bridge can be used btwn the interlocking and before Aqueduct N Conduit there is a switch on the northbound center track there because the track north of it is yet to be replaced

that switch and active track were there becuase when Howard beach was renovated for Airtrain, the temporay northbound platform was on the Northbound local track (F2), so trains used F4 (northbound express) and that switch was installed south of Aqueduct/NC. Southbound trains stayed on F1 as that platform was on F3

http://www.nycsubway.org/perl/show?27014
here's a pic of said situtation I found on NYCsubway.org.

why they didn't make a large island over F3 and F4 is beyond me.