MK Possible small tunnel addition to the Princess Meet and Greet building starting near the Tunnel entrance/Wardrobe - Not confirmed.
It would make sense to extend the tunnels to the northeast a bit, since they never really accommodated the ToonTown area. Stairway #23 is as close as you get, currently, and I'm not 100% positive where it actually comes up.
I doubt the tunnels have to be ADA compliant, since 1) they predate the code, and 2) they are not for public use.
Edit: Sorry for the double post, I forgot this board doesn't automatically add your posts together if you're the last poster still.
If they've done more than a few thousand dollars worth of work (and I know they have) to any specific facility, it must be brought up to current ADA code. However, the MK utilidors have always been fairly accessible, since they're ramped or flat, have a main entrance from grade, and have elevators at many stair locations.
ADA applies to public and private areas. You can't deny employment (for non-casted roles) because someone is in a wheelchair. So, the tunnels so, in theory, need to be accessible.
my source is a Traditions class I was in when I became a cast member, it was on a video they showed us. And I have worked at MK before and been in the tunnels and seen signs that say fallout shelter. Maybe it wasn't during the cuban missile crisis, but I have seen thats one of the reasons it was built. The big doors have since been taken out, but I tell you, they were going to be used as fallout shelters.
I've seen photos of the tunnel construction. The walls and lids are not suited for any type of blast or radiation. The concrete isn't thick enough, and there is no radiation shielding.
Besides, there are nearly 30 entrances to the tunnel system making it infeasible to shut blast doors of any type in a short time span.
The primary, documented reason for the tunnels was to provide a way for CMs to get from wardrobe to their work location without ruining the magic. And, to provide a more efficient way for F&B and Merch to distribute goods.
An added bonus was that they could install all of their underground utilities in an exposed manner. Many large cities have similar tunnels under their streets for the very same reason - they just weren't designed for humans to work in (for long periods of time).