This should be a nice easy cache to find, just on the perimmiter
of Pont Abraham Service Station.
Note however that the small layby nearby (which may also provide
parking right next to the cache) is a favorite spot for PC Plod to
park while waiting to be called to chase criminals so if he's
there, I suggest you "let the wookie win" and come back later,
otherwise questions may be asked regarding tupperware boxes being
retrieved from hidden locations...
It has also come to my attention that the motorway service
station is now a free WiFi hot spot - a good location to plan for
other caches while travelling perhaps along with grabbing the other
Motorway Mayhem that's within walking distance (GC1C2Y5), placed
coincidentally on the same day as mine!