I would have my phone with me anyways. F**k schools, what if you literally NEED your phone, but aren't allowed.
Same for weapon-free zones. I ignore those f**kass signs and carry anyways, because I'm not going to be sitting like a goat while someone tries to blow my head off, because criminals will do what criminals do and ignore the sign. And the signs are unconstitutional anyways, they can't take away my second amendment rights.