Parts 1, 2, and 3 are just information the average person should know and simple precautions to take in the event of a nuclear terrorist incident that involves normal fall-out. Becase, in the event of a mass evacuation, many will probably be stranded on crowded and blocked exit highways, these were instructions for protecting yourself in place. It may be safer to hunker down in a place you know, like your home or lake cabin.
These instructions generally do not apply to radiation incidents caused by reactor leaks and "dirty" bombs. The half-life of that radiation is considerably longer than that of fall-out. Before anythng happens, as part of your disaster preparadness, it would be a good idea to look up your local radiation emergency center personnel and find out how to get information from them during an emergency.