And subway woe, for good measure

A computer glitch brought seven subway lines to a halt for more than 90 minutes Friday evening, stranding rush-hour commuters in trains and on sweltering platforms as city temperatures hung in the humid 90s.

Transit officials blamed the suspension of service on the 1, 2, 3, 4, 5 and 6 lines and Times Square-42nd Street shuttle on a problem with computers that power the subway’s signaling system — apparently the same culprit behind a similar service screw-up on July 6.

“I absolutely want to get to the bottom of this,” subways boss Andy Byford said, promising an investigation into what caused both service outages.

The “total stoppage” began at 5:50 p.m., MTA spokesman Tim Minton said. Service began to be restored at 7:16 p.m., but residual delays continued into the night.

Without signals “we did not know exactly where our trains were,” Byford said.

“So for safety reasons, we had to instruct all trains to stop where they were and maintain their positions while we ascertained exactly what was going on,” he explained.

The signaling snafu was solved by simply rebooting the system’s servers, Byford said.

“Once we could be certain we . . . could safely move the trains, we instructed a phased restart and trains began to move,” he said.

The stuck trains never lost air conditioning or lighting. Still, straphangers were not happy.

“A systemwide shutdown in July when its 90 degrees? And they’re raising the fares again?” asked annoyed commuter Tanya Layne, 30.