"For visitors he wants one person in the group to be wearing hi-viz while airside and he wants them to keep the group together. His concern has been that in the past groups of "escorted" visitors have not been kept togther and have straggled all over the place. You can see that a group of schoolkids or (even worse) photocopier salesmen on a corporate jolly being walked between AV8 and the hangars could cause some worry as they pass the fuel point and taxying aircraft or helos with rotors turning."
Seems to me that keeping people in one group has little to do wiith the requirement to wear hi-viz vests!