Water access supersedes land access by law, I think they only have to give 30 minute or an hour notice but most of the time they try to do it not during rush hour and schedule further ahead IIRC. I used to be late periodically because of asshole ships forcing the portal bridge to open and holding up multiple trains full of people. Once the portal bridge got stuck and we were stuck between Newark Broad and Secaucus for 3 hours or so.