The charity organisers need to be educated to realise they cannot monopolise a path in this way.Dartmoor does have big events like the 10 Tors, but the groups are given many different routes to follow so that they remain spread out.Cycling events occasionally monopolise the roads, but these are rare - and occasionally there is a German tour bus that wants to sit in the middle of the road, but the locals have a habit of making them wait, and I think they get the message.