I mean really Javier, you're not being thoughtful at all with any of your recently posts in this thread. It makes me wonder if you take the subway regularly or you don't take the subway regularly at all. For starters, I'm not quite sure if either you yourself or a friend of yours is making these kinds of ideas, but I assume it's the former. If you want to make a good idea, you would have explain why you made your ideas the way you did as well as being logical and sensible about it. Instead of just simply posting them out of the blue.
You can't send the to the Lexington Avenue Line permanently because the and already do the work and their combined frequencies is sufficient enough to handle the crowds. Also, there's no need for express service on the Jerome Avenue Line either, because trains would just carry almost nobody since the majority of the riders are headed towards the local stops from Manhattan or are coming from the local stops on their way to Manhattan. What would become of both Harlem-148 St and 145 St stations then? Not to mention the cannot handle all the stops on the West Side by itself, unless you boost the number of trains on the entire line that is, which I also don't think is necessary either.
You can't cut the back to 14 St, because that would just delay trains trying to come through on the express tracks. They would have to be on the local tracks in order to get through 14 St. Why is that necessary? I mean you eliminate through service between Harlem and New Lots, and forced more and more people to transfer between trains trying to get to/from Brooklyn or the New Lots branch.
Also, why should the 1/9 go to Brooklyn for? Is there an actual demand for it? A "one-seat" ride doesn't count, it's about demands and crowding. The runs very frequently enough to delay service at Chambers Street and the poorly built Rogers Junction as well as the not-too-good Flatbush, Utica and New Lots terminals. You already have the and doing the work between Lower Manhattan and the Brooklyn IRT. Why throw another line into the mix? Look at Rogers Junction, where trains are always being held to let another one cross infront of the other, most notably the and .
As for express service on the upper Broadway-7th Avenue Line, that's not necessarily a bad idea, but you need to understand if there's an actual demand for it. Do people really need a faster commute to or from the area? Many people on the are only going a few stops. There's a reason why the 1/9 skip-stop was eliminated years ago, because it didn't save much time as it was local almost all of its route, as well as people only staying on the train for a few stops. As opposed to the J/Z skip-stop, where many people are on the train trying to get to Manhattan (and not a few stops).
Again, you're not thinking any of this through. The point is to keep every line going to one destination from end to end and minimize confusion & delays, keeping things as simple to comprehend as possible. We've been clear numerous times about why the old was eliminated from South Brooklyn and Lower Manhattan and rerouted up to Midtown Manhattan and Queens Boulevard. It was to cut costs and many people from the West End Line are on their way to/from Midtown Manhattan and not Lower Manhattan. Why else do you think the Montague Street Tube sees the lowest amount of passengers than any other East River crossing in the entire subway system? If that wasn't the case, they would have never eliminated it, nor would they have eliminated the either and replaced it with the current .
Also, slow speeds doesn't necessarily mean reroute some trains here and there, unless there is a major blockage in the area or capacity constraints. Do you ride the Queens Boulevard Line on weekends? Another thing: take a look at all the flagging with track/signal maintainers on every outdoor line during middays and weekends. Slow speeds, flagging, rail condition etc means that a train would be at most 15-20+ minutes late.