So I was looking at the subway track map this morning (https://www.vanshnookenraggen.com/_index/docs/NYC_full_trackmap.pdf), and I realized that the tunnels in between Manhattan and Queens are imbalanced in terms of how many lines they serve.

For this post I'm gonna use terms that I made up, but basically in my mind a service that runs exclusively on its own track is a "full" service and a service that shares track with another service is a "half" service. For example, the full services are 1,6,7, L, and J since they don't interline with anything (Z doesn't exist). Half services are basically everything else, such as how the 4 and 5 share the lexington express tracks. You can interline any two half services together to combine to a full service, like how the A and D interline together to form a full service on the central park west express tracks.

With this in mind, the 7 train tunnel is two tracks and serves one full service, so it's at capacity. The 53rd st tunnel has the E and M, two half services interlined together. But then you have the 63rd st tunnel, which has only one half service, the F.

And finally, the 60th st tunnel, which has three services running through it. From this tunnel, all the way south to times square, is the only location in the entire system where three services combine into one set of tracks. It's well documented that this tunnel is a bottleneck in the system. Combined with the shitshow at the DeKalb interlocking, the capacity of the BMT lines is severely constrained, with the R possibly being the line with the worst headways in the entire system.

Why is it like this? Can this be fixed? For my following suggestions, if there's any scheduling nuances or reasons why the ideas wouldn't work, please enlighten me. I don't know much about scheduling and I'm just laying out what makes sense in my head. I'd really like to know why the system is run this way instead of maximizing the capacity of each tunnel.

My idea for fixing this and increasing the capacity of the BMT broadway line has a couple of small components, but overall there are no new infrastructure requirements (as far as I'm aware), and there is no decrease in service anywhere except for one station, which is more than made up for by the increase in service system-wide.

First, eliminate the W train. It's a weird combination of N and R service and it doesn't even go into Brooklyn. It also causes problems for the next two suggestions.

Second, have the N run fully express, and stay with the Q train into the 63rd st tunnel. There is a switch in the tunnel to allow trains to cross between the BMT and IND lines, and the N should take advantage of this switch to interline with the F train in the tunnel. This increases capacity at the Lexington Ave, Roosevelt Island, and Queensbridge stations, as now the track is completely full instead of half.

But then where does the N go after this? Well, the third suggestion is to remove the R train from the Queens Boulevard local line and replace it with the new N, and then send R trains from the 60th st tunnel into Astoria. This would eliminate the connection between the R and the Queens Plaza station, but the rest of the Queens Boulevard line remains at full capacity with the N running local where the R previously ran.

Finally, since the W doesn't exist anymore and the R goes to Astoria, the amount of trains running along the R line can be increased to a full capacity. The R would now join the short list of trains that don't interline with any others, since it's alone in Astoria, Broadway local, the montague st tunnel, all the way down 4th ave in Brooklyn. This can finally end the decades of the R being utter dogshit, as it will be able to run at quick headways since it doesn't have to share tracks with anything.

Other than the loss of a third half-service at Queens Plaza station, are there any downsides to this? Astoria, Broadway, and Brooklyn all get more service. The tunnels between Manhattan and Queens are used more optimally. There's no delays because of the N swapping from express to local tracks north of times square. I'm assuming that there's a reason service isn't run this way, so if anyone more knowledgeable than me could explain, that would be appreciated!