Of course, the mix of workforce at LHR is more closely related to the mix of people in the Hounslow area than it is to the population generally. It would be unusual for someone to commute to work, especially low wage work, at LHR all the way from the Orkneys. That said, the training issue is key and was noticeable when I passed through the other day - in fact a well trained supervisor suggested I went through the old process as the new process was still unfamiliar to most people and was taking much longer.