There are several grades of shelters. At the initial bug out from Katrina, many opened here for refugees (and we're 300+ miles away and not on a major highway). The people that came here came under their own control, in their own cars. After the hotels filled up, shelters opened at community centers and churches. We helped out in those; they were universally well run and reasonably secure. Many of these people stayed long term, and we're happy to have them.
Then the second wave; those that didn't leave NOLA and ended up at the superdome. They were first bused to Houston, and then distributed and 500 ended up at the university basketball arena. The local paper reported 5 to 10 arrests daily there, and remember, thats out of 500 people, many of them children. This included a transgendered person who insisted 'she' use the ladies showers despited evidence 'she' wasn't female....
As the people with means found places to go, those at the arena were distributed out to the other shelters, spreading the security problems with them.
- A smaller town off the main highways would be a good spot to head to in the event of a natural disaster.
- Avoid big shelters at all costs; small groups of people are accountable to each other, but large groups of people are problems
- Avoid at all cost shelters where groups of people are relocated to by govt order. You're much safer in a tent somewhere.