In 2018, the on-time rate improved.

[Read more: Why the subway is no longer a disaster.]

Only two of 22 train lines have modern signals.

As The Times’s Emma G. Fitzsimmons reported, experts agree that the only way to really improve New York City’s system is by installing modern signals to replace antiquated equipment, some of which was built before World War II.

Today, only two lines have modern signals: the L and the 7. They are the best-performing lines in the city, with on-time rates above 90 percent.

It cost about $400 million for new signals on the No. 7 line. Installing new signals across the entire system is expected to cost billions of dollars.

What’s next for the subway?

According to Ms. Fitzsimmons, the next critical moment for the subway will come this month, when the Metropolitan Transportation Authority releases its five-year capital plan, which will outline its priorities for 2020 to 2024.

The leader of the subway, Andy Byford, says installing modern signals is the key to improving service.

Will the M.T.A.’s capital plan include money for that? Transit advocates say it must in order for Mr. Cuomo, who effectively controls the M.T.A., to prove that he is committed to improving the subway.