Is the main culprit behind delays the aging equipment in the 112-year-old system — signals and tracks taxed beyond their limits and patched together to eke out a few more creaky years, only to break down again and again?
That is certainly an enormous problem, but it is not the No. 1 reason.
The major cause of subway delays is a factor that basically did not exist 15 years ago: overcrowding. The subway is a victim of its own success and the city's resurgence. Large crowds slow down trains, which creates more crowding in a vicious circle that takes hours to unwind during every rush.