According to a recent article by the New York Times, 85% of New York City’s subway system relies on a dated analog signal system that was put in place nearly a century before.
The system essentially works as a network of trackside lights and electrical circuits. Through “block signaling,” train operators are able to tell when certain blocks (tracks divided in various sections) are occupied by another train. Train operators must watch for these trackside signal lights to ensure enough distance is kept between every operating train to prevent collisions.
Moreover, Dyanesha Pryor, as mentioned in the Times article, handles the system’s “interlockings” (points where subway tracks crisscross). Ms. Pryor and other control tower operators must manually move levers in a row of 24 to safely merge express and local traffic at intersections.
The entire operating device is about as large as a grand piano, explains The New York Times. Certain levers allow parts of the tracks to shift, while others signal red or green lights
Though the interlocking machine was created with various lever maneuvers to protect against human error, it still requires around the clock human presence.
If Ms. Pryor has to leave for a bathroom break, all express trains must run local for the time being with no one there to operate the interlocking machine.
The antiquated system is to blame for many of the subway’s notorious delays. If you live here, you wouldn’t be surprised to know that the subway can see up to several hundred delays per day.
However, the city intends to update this nearly century-old system with communications-based train control (C.B.T.C). This modern system is being used across other global metro systems including London and Paris.
In this system, wireless communications replace human necessity for monitoring train movements, with real-time and precise information sharing between trains and control centers.
However, if congestion pricing gets terminated and if the MTA’s next capital budget gets defunded, NYC’s expansion of CBTC could be at risk.