On the other side was a room containing highway signs, construction blockades and other standard non-lethal traffic equipment. I assume this part of the tunnel complex is accessible and being used as storage by the Muni yard next door. This explains the graffiti in this section, as well.
At this point, I didn't want to go any further into this section, as I try to avoid live sites until I have a better understanding of where the line lies between trespassing and burglary. My late trubbamaking companion, however, just had to see what was in the next chamber before we turned around. We stuck our heads through the door, and it was a long hallway with three tractors parked in it.