That is all very well but the roads will still be there with many cars going by every hour

Along the one main road yes, but this is a short term proposal based on the assumption that that isn't going to change for many a year.

I don't know the figures but would guess that the great majority of visitors arrive by car or coach. I would have thought that they'd think £10 to cover free parking, an exhibition, an hour long tour of the landscape and access to the much enhanced site would be a pretty good deal.

Whether it would be worth accommodating those who arrive purely as pedestrians by erecting a perimeter fence round parts of the outside and charging them a couple of quid... or simply having honesty boxes or just letting them walk in free I don't know... but I'm sure it wouldn't be a major problem and wouldn't prejudice the main exercise.