Our public-transportation woes are the key marker that New York City has become a “catastrophic success” — something so popular, it outstrips its own capacity to serve the people flocking to it.

The city’s quarter-century comeback from the muck of disorder into which it had descended — from its near-collapse in 1975 through the crime wave of the early 1990s — has been one of the wonders of our time. But it has strained the city’s infrastructure to the breaking point.

If this were 1982 and the A train had derailed of its own bizarre accord near the 125th Street station at 9:50 a.m., as it did on Tuesday, it would’ve been far less meaningful. Why? Because so many fewer people were riding the subway in 1982.

In 1982, the system logged 899 million rides. Last year, it was 1.7 billion rides. The busiest station in the system, Times Square, had 37 million riders annually in 1975 — and 66.4 million in 2015.

This is of a piece with the population numbers. In 1980, the census found 7.07 million living in New York City. That grew to 8.5 million in 2016. The number of commuters coming into Manhattan has grown dramatically.

How about tourism? Thirteen million out-of-towners visited New York in 1990. In 2016, it was 60 million.

It’s right and proper that the politicians who run the transportation system — especially Gov. Andrew Cuomo — are getting raked over the coals. Cuomo is always ready to cut a ribbon. What needs to happen to save the city’s transportation network is the opposite of that.

We have a decades-old maintenance deficit. Everyone involved in keeping the system healthy has been more interested in showing off shiny bells and whistles than in the unglamorous scutwork that keeps our multifarious marvel of urban engineering — New York’s subways, trains, buses, bridges, streetscape, roads — on the move.

In the end, it all comes back to the rails. Those 850 miles of subway track constitute the life’s blood of the most economically powerful city in the world, a city that generates around $1.5 trillion annually.

Atherosclerotic plaque is slowing down that life’s blood and causing daily bouts of commuter angina — and threatens to attack its beating heart and stop it dead.

We’ve created a political ­dynamic in the region that is designed to shift blame: The MTA, which runs the subways and two commuter railroads, has 17 directors beholden to various political pooh-bahs. The Port Authority, with its bridges and tunnels and another commuter train, is run by two states, so any problems just lead to convenient finger-pointing both ways across the Hudson. Amtrak, which runs another set of trains, is a weird public-private entity with no clear controlling authority.

The buck has been passed forever. Now it’s judgment time.

Chris Christie will end his governorship as a failure in part because of the horrific managerial hash he has made of his transportation responsibilities. And any national ambitions Cuomo may have will stand or fall now on how he handles this state of crisis.

We must all hope those ambitions gnaw at New York’s governor every moment, because that is the only hope we really have of getting out of this catastrophic success without suffering through a genuine catastrophe.