If you look at the north end of the track on Google Maps, find the Dunlop Bridge.
North of that is the D323, and there's a footbridge [Co-ordinates: 47.959561, 0.21156] crossing to an area bordered by the D323 to the south, the Avenue du Panorama to the north, Rue de Laigné to the west & an industrial unit to the east.
I'll put money on that being the area in question.
Paul.