On the road from Montaud to Autrans, before Mortier tunel (road really closed : take off not accessible from Autrans).
Montaud village is 5 km south from Voreppe -via Veurey- 15 km NW from Grenoble.
Take off is on road side ... no walking !
Impressive for beginners : good slope, not too wide, but no real danger if breeze is present.