One of the most obvious ways in which humans influence sand dune systems is by trampling.  In front of a sand dune system is always a beach, and of course humans often want to be on that beach.  Behind sand dune systems car parks are often situated so one of the commonest ways in which sand dune systems get trampled is a from car park to beach.  Many paths therefore run at right angles to the dune ridges.

Another common footpath is along dune ridges, such a walk affords a good view often of the sea on one side and the rest of the sand dune system on the other, people are very keen to walk along here.  Such a dune ridge path as shown below.

So, how does this trampling affect the vegetation and the soil in the trampled area?  A lot of research has been done on this and you can look at a virtual study by clicking here.