We received a tip today that people had seen a mysterious 8 train roaming through the tunnels of Manhattan, and found the above picture along with this post on Reddit: "A friend of mine grabbed this shot of one of the cars on the 7 train. Can anyone explain this?" Considering that the 8 train hasn't been in service since the 1970s, we were curious as well, so we spoke to a representative from the MTA who gave us the low-down on the error:

"Just a mistake. Signs come with numbers that we don’t use like 8 and 9 in case we should ever want to use them. It was probably turned to 8 inadvertently in the yard," the MTA rep told us. As others surmised, the 8 is a remnant of an older subway rollsign mechanism that happened to be on display—in addition to the 8, IRT also has a 10 and 12 in its current rollsigns. However, there have also been rumors that the 8 has been a proposed re-designation of the express 6. So we may very well have an 8 train in the future!