Hmm... you can read this just as well as I can, and it seems a knife isn't really a problem. I would check with local LEOs and maybe an ADA to make sure it's okay to carry something like a LM Wave or pocket folder. I *KNOW* I've seen NYC construction guys (both independant and city workers) with a LM pouch before. But that's been maybe 6 years ago, so things may have changed.

If not, they have pretty lengthy rules of what you can't carry, but a sturdy umbrella like one of these guys, seems like a smart way to go.