Very nice find, played it on solo last night, I thought I found some train locations, one place was a big lap involving falling down a floor, then making your way back up again and repeat, but the zombies can jump up a level. Tried the sewing room where the power switch is by running laps around the table but you easily get intercepted. This glitch is very good since doing a rape train is hard right now, just gotta explore the map some more