Here's the 5th incarnation of my map. Aside from maybe a few minor tweaks, I think this will be my last version for awhile. To sum it up, here are a list of the changes from the actual present NYC subway service:
The Second Avenue Subway is completed. It runs under the presently projected alignment (here), with the exception that the "T" is diverted to the Nassau St line via the former loop tracks to the Manhattan Bridge, thus providing better access to central Downtown. The SAS is now a major trunk line in the system, to which exists these branches:
A new crosstown is built in Harlem along 125th St, extending from the present tail tracks planned in the present SAS design. The "T" now connects all upper Manhattan lines to Morningside Heights on the West Side.
Subway service is provided to Co-op City: Continuing north from the SAS, the Broadway route tunnels under the Harlem River to Third Ave in the Bronx and connects to the IRT at 138 and 149th sts. It continues along Third with a stop at 163rd then heads under Boston Rd stopping at 169th Sts and Louis Nine Blvd, then shoots NE to 180th St to connect with the IRT, sharing the station building there. It then makes it way along the Amtrak ROW to about I-95 where it turns north under Co-op City. With spread out stops along major bus routes and a direct shot or a single transfer away from the East or West side and Midtown and Downtown, and access to the shopping areas of Bay Plaza and the Hub, as well as giving subway service to Melrose and Co-op City, this line more then shows it potential economic benefit.
The SAS's connection to the Queens 63rd St tunnel is utilized. The "V" is routed through 63rd St to the SAS where it gives Queens residents easy acess to the East side.
New Brooklyn service: The "T" and "V" makes their way into Brooklyn, providing fast super express service from Downtown Brooklyn and Lower Manhattan. The "V" is a rush hour West End express and the "T" runs down a new subway tunnel (one probably very unlikely to ever be built) along Dean St, stopping at Washington and Nostrand Av's, before curving under Utica Av to proving much need subway service to SE Brooklyn. There it runs down Utica then Kings Hgwy then under Flatbush Av to Kings Plaza. Of course, as this route would require loads of new tunneling (about as much as the SAS mainline), as there are no existing railroad ROWs than can be hijacked, and services a much more economically unimportant area than the East Side of Manhattan, I highly doubt this will ever happen.
East Queens service: The periphery of Queens sees needed subway service with the extension of the "F" along Hillside Ave and the "E" to Laurelton via the eastern section of the LIRR Atlantic branch.
LaGuardia Airport rail link: A new subway is built to link to LGA. Via the Queens Blvd express tracks a line veers off along Northern Blvd to 83rd St where it turns north towards LGA. I picked this option over extending the Astoria line because this seemed easier to construct (no need to sink El's underground) and provides faster access from Manhattan.
Flushing Line extension: Extended on both ends, the "7" is extended on the West side as presently proposed and extended on the East end as a new subway under Union St and Parsons Blvd then east to Beechhurst. A lot of new tunneling, and probably quite useful, but again, probably highly unlikely to ever be built.
In addition to the new construction, there are some service tweaks that could be implemented to existing services:
"1"/"9" Skip-Stop eliminated: The 1/9 skip-stop, which in terms of speeding service is a complete waste, the 9 instead as been changed to an extra local service that terminates at 137th St, providing extra service to the heavily used stations between 96 and 137. A minor change to the 137th St Yard makes this change possible (here)
BMT Broadway line express service increased: "Z" trains now run express between Broadway Junction and Myrtle Av peak direction
Culver express service restored: Full time express service proved to Church Ave via an extended G local. The "K" has been resurrected as a 6th Av/ Culver local, terminating at 72st/2nd Ave on the planned middle track. Rush hours it is extended to Kings Hgwy allowing peak direction "F" express service.
In addition, I'm considering scrapping Brooklyn "M" service since with the SAS lines it seems redundant.
What do you folks think about these? Some of these changes we may see in the future (SAS, Hudson Yards "7" extension. Others, I hope we see in the future (Co-op City line), and the rest, I wouldn't could on it (Beechhurst extension, Utica Ave line) I going to submit this map to the MTA and see what sort of response I get out of them.