Why here?

This group of ponies together with their young, are gathered beside the main road across the moor with cars, lorries and coached thundering past inches from them. There is a 40 mph speed limit throughout the National Park but not every one sticks to it yet all along this road you will see these groups gathered beside the road.

Its not to be fed as there is plenty for them to eat at the moment and its illegal to feed them anyway. So why, with all this open space do they do it ?