You can just see the A3 in the bottom left of Tim's excellent picture; you'll note the western end of the runway is on what looks like an embankment; that's the only bit you'll see from the A3.
If you were to park in the layby on the westbound slip road joining the A3 from the M25, there's a small track off to the left which I presume is the old airfield entrance; it IS private property (I happen to know who administers it - but I've been asked not to let on) however there are public rights of way which cross it, so provided you stick to these, no-one should object.
By the way, the OCK VOR is visible just below the turning pan at the far end.