If a role-over cage is fitted by the manufacturer then seat belts are also fitted as the idea is to stay inside the protective cage should a role over event happen and in theory the seat belt will restrain but to date the belts that are generally fitted are, in my opinion, not as good as they can be nor is there proper 'role over' training The problem is the one you describe; so evaluate all options and make your decisions [that is the hard part] noting that a piece of kit even fitted by a professional is no good if it is not worn for a sensible reason and even PUWER allows for a situation where the role over bar can be lowered then it must follow that at that time the seat belt is not to be worn as if it was it could trap a person The secret is sensible management and trying to get staff to buy into your final management system. Additionally on investigating a number of role over accidents is was found that in one case the seat belt was worn and it trapped the guy inside where his hands ended up between the ground and the kit but not his head nor body and another event the guy jumped clear because he had no belt on. He was hurt on landing - you sometimes cannot win

After a sufficient assessment RA..You would have to define your policy on this issue..Which as you rightly state would be difficult to enforce as staff would push the boundaries... Put simple instructions sign on the vehicle, but make sure its on the drivers vehicle daily check sheet (before use checks) And ensure they have been informed how to do these checks. This mean's they know the rules and if it is not there they are already contributory negligent for using vehicle. In Ref FLT. If you read safe use if Fork lifts.. They don't have to wear at certain times. But there is a criteria..(which I believe one is Ground Conditions (FLAT & LEVEL)

See L22 PUWER regs 25,26,27 Page 62 onwards this may help.. You will find it free to down load from the HSE Website

Further to my last post I have been really working on this issue at our workplace in coming up with a sensible and practical system that our employees can work to. We are bringing in a 'train the trainer' course and formalising training rather than just "in house". As I said before much of the work that is carried out is on flat arable land and getting in and out of ATVs in paddocks and fields every 20-30 mtrs or so to 'muck pick' and fill bins with animal feed from feed buckets carried on back of ATV. We want to ensure that seat restraints are done up on tracks (some of which are public rights of way - walkers, hikers, school kids) and this is in place already, however it is working within these enclosed areas (fields/paddocks) where there is negligible risk of overturning or contact with anyone else and we want to be practical about working practices - our employees would be doing up seat restraints dozens of times a day over short distances and may only be travelling at 5mph on woodchip!! One suggestion is as we are now investing a lot more in theoretical training as well as practical training is that we put the onus on our trained drivers by stating in the risk assessment the "seat restraints are to be worn on all tracks" and "in other areas where there is a risk of overturning" - but I'm not sure if we need to be more prescriptive. We also have a strict speed limit on site already. Talk about caught between " a rock and a hard place"!! Apologies for lengthy tome but I'm finding this a difficult issue.