That's assuming normal traffic flow. As someone famous said "quantity has a quality all it's own" - in large traffic flow conditions (as is the case with an evacuation), are all the same security precautions taken? Can they be sustained without a huge bump in the security staff? If new security staff are used impromptu, will they follow the same stringent standards?

I agree with VLM - these people should have been secured in place and not herded through a chokepoint in a rush.