North of this station are tunnel stub headings running straight from the local tracks for a proposed line under Central Park West or Morningside Avenue, that would have terminated either at 145th Street or 155th Street.

When the BRT / BMT was building the Broadway line as part of the Dual Contracts, the company also wanted to be awarded the Central Park West / Eighth Avenue route, which was on the planning boards at that time.
The company figured that if they built ramps from the Broadway line that could naturally be extended to an Eighth Avenue line, they would get a toehold on being awarded that line, rather than lose out to the IRT, the only other subway operator when the Dual Contracts were built.
The BMT / BRT never built that line for various reasons including the bankruptcy of the company after the Malbone Street Wreck and Mayor Hylan's plan to include the Eighth Avenue / CPW route in the IND system.
The ramps were built but never used for revenue service.
They were eventually used for storage until the tracks were disconnected.

The disused trackways for the proposed line ramp up and run for about 500 feet (150 m).
The ramp on the northbound side has a Maintenance-of-Way shed built on it, and the trackway on the southbound side also has a storage shed sitting in it, just north of where the local tracks come in, but this shed is few hundred feet north of the shed on the opposite trackway of the other side of the tunnel.
Some of the actual rails remain and can be seen from passing express/63rd Street Line trains, but are covered by many years of dirt.
The never-used trackways curve slightly west before ending.
North of this station are tunnel stub headings running straight from the local tracks for a proposed line under Central Park West or Morningside Avenue, that would have terminated either at 145th Street or 155th Street.
When the BRT / BMT was building the Broadway line as part of the Dual Contracts, the company also wanted to be awarded the Central Park West / Eighth Avenue route, which was on the planning boards at that time. The company figured that if they built ramps from the Broadway line that could naturally be extended to an Eighth Avenue line, they would get a toehold on being awarded that line, rather than lose out to the IRT, the only other subway operator when the Dual Contracts were built. The BMT / BRT never built that line for various reasons including the bankruptcy of the company after the Malbone Street Wreck and Mayor Hylan's plan to include the Eighth Avenue / CPW route in the IND system. The ramps were built but never used for revenue service. They were eventually used for storage until the tracks were disconnected.
The disused trackways for the proposed line ramp up and run for about 500 feet (150 m). The ramp on the northbound side has a Maintenance-of-Way shed built on it, and the trackway on the southbound side also has a storage shed sitting in it, just north of where the local tracks come in, but this shed is few hundred feet north of the shed on the opposite trackway of the other side of the tunnel. Some of the actual rails remain and can be seen from passing express/63rd Street Line trains, but are covered by many years of dirt. The never-used trackways curve slightly west before ending.
57th Street–Seventh Avenue station