It’s not supposed to be an adventure to get off the subway, but it was a choose-your-own kind of day on Tuesday after an A train derailed near 125th Street.

Maybe, like Michelle Ayoub, you slogged through darkened cars on that A en route to a platform connection. People had been crying and praying aloud. “We just wanted to get to the light,” Ayoub said.

Or you were with Margaret Arias, 25, when she walked a plank from a C to an express D, both stuck due to the A’s dilemma.

Perhaps you braved the rats, a particular fear for Keyanea Wright, 25, who took her chances when directed by emergency personnel to depart by the tunnel-side doors, down a ladder into the tracks, up another ladder to safety.

Then there were the 500 who just took matters into their own hands and “self-evacuated” into the tunnel, according to FDNY Commissioner Daniel Nigro, which he called “very dangerous.”

These were your choices yesterday on a wild subway day, starting around 9:45 a.m. when the downtown A bucked forward, bucked back, came to a halt. There were dozens of injuries, but even for the uninjured there was panicking, with sparks flying outside the car and locked doors prohibiting movement through the darkened snake of cars. That wasn’t going to fly for some passengers who kicked in a window. Smoke swirled, a straphanger vomited, and riders helped each other — lending a hand when a fellow rider had a hard time traveling between doors on the long dark march to fresh air.

They eventually emerged. And the system did what it does even after far more minor issues: it practically ground to a halt. Cascading delays meant service was suspended on entire lines. The MTA relocated platform controllers to stand around 125th Street offering alternate travel advice and handing out subway maps, though a woman who gave her name as Merlin beat them to it just outside a shuttered southbound entrance.

“No service here,” she said to confused passersby. “There was a train derailment,” she added, making the sign of the cross with the final word.

Not present at the site: Mayor Bill de Blasio, who on Monday managed to hit the opening of a new Junior’s Cheesecake. Or Gov. Andrew Cuomo, who effectively controls the MTA and has made it his habit to show up at accidents from New Jersey to Brooklyn. But nobody wants to seem responsible for the mess that is the MTA these days.

Some riders who’d been stuck underground couldn’t find it in them for once to worry too much about tardiness, so happy were they to be safe. Plans could be changed, work pushed back, meetings rescheduled. Wright, who had been on her way to class at the Mandl School for medical professions, said with a rueful smile that she sent a paper to her professor, knowing she’d be late.

But give them time, and their shell shock will likely wear off like everybody else’s.

“Yes this is business as usual, and yes I’m concerned,” said Victor Sanchez, 62, a Harlem resident who teaches poetry and counted himself lucky he could walk over to the nearby 2 and 3 line for his travels in the afternoon.

Sanchez said he was only an MTA expert insofar as he rode the train every day, but it was clear that the neglect has piled high. “Throw some real money at the problem,” he says. But he has an idea how that’s going to turn out.

“Next year, they’re definitely going to ask us to pay three dollars for this.”