All revenue trains run from the same 625V DC third rail. What may have you confused is that up until 1999, all revenue trains were equipped with DC motors. At that time, new train cars began using AC motors, although still running off the DC third rail.

The New York City Subway system runs on Direct Current (DC) power. Specifically, the third rail provides approximately 600 to 650 volts of DC to the trains' traction motors. DC was chosen in the early 20th century because it allowed for easier speed control and was more efficient for the short-distance, high-torque requirements of a city transit system at the time. While the power transmitted from utility companies to the MTA's substations is High-Voltage Alternating Current (AC), these substations use massive "rectifiers" to convert it into DC before it hits the tracks. In 2026, while modern subway cars (like the R211) actually use "inverters" to convert that DC back into 3-phase AC for their highly efficient internal motors, the "lifeblood" of the actual track infrastructure remains the same 625V DC standard that has powered the city for over a hundred years.

The New York City subway uses direct current (DC) for its trains.

Here are the key details:

• Third Rail Power: The subway gets its power from a 600V DC third rail (a conductor rail running alongside the tracks).
• Traction Motors: The trains use DC traction motors, which are well-suited for the frequent starts and stops of subway service due to their high torque at low speeds.
• Historical Reason: When the subway system was first built in the early 1900s, DC was the standard for urban rail systems. The technology was mature, and DC motors provided the necessary control and power characteristics.

Important Modern Nuance:

While the power delivered to the train is DC, the modern system is more complex:

1. AC to DC Conversion: The power from the commercial grid (which is alternating current, or AC) is converted to DC at substations before being sent to the third rail.
2. Onboard Inverters: Modern subway cars (like the R160 and newer) often use AC propulsion systems. They take the 600V DC from the third rail and use an onboard inverter to convert it to AC to power newer, more efficient AC traction motors. This allows for better energy regeneration during braking.

In summary:

• Power Source (Third Rail): 600V DC
• Original Traction Motors: DC
• Many Modern Trains: Use AC motors, but they still get their power from the DC third rail and convert it onboard.

So, while the delivery system is firmly DC, the technology on the newest trains involves both AC and DC systems for greater efficiency.