I think hi-viz jackets are a very sensible idea, it may just save someone's life by helping pilots see people not paying attention while walking on the movement area. In fact I have just written a letter to the DofT and CAA suggesting not only this be made mandatory but also recommending some form of permanent security at the busier GA fields such as White Waltham, Kemble, Barton, Popham etc. Not only will this create jobs but it will also make GA far safer than it is at present, it could be anyone the vicinity of aircraft and without an airside pass system. You can't be too sure! Trained security staff at GA fields would solve this, we need to move with the times!