I believe
@Chuckman works at Duke hospital, which would put him in the "educational property" category, like I am. I too could likely carry and nobody would be the wiser, but being educational property the penalty is more than losing your job. Having made the determination that I will not go to prison getting caught with a weapon would have the same outcome as getting caught by a violent and homocidal criminal. The fact that given my travels on educational property, put that probability, while not zero as this has happened to people, lower than the likelihood of getting caught up in a search, which has also happened.
Consequently, in my case the risk posed by carry is greater than the risk of not carrying, but then I don't work in the ER either.