Franz Josef sits on State Highway 6, the West Coast road that runs the length of the South Island's western edge. There is no train and no commercial airport — everyone arrives by car or coach.
From Greymouth (and from Christchurch via the Arthur's Pass road) it is around 3 hours' drive south. From Wanaka and Queenstown the route is over the Haast Pass — a spectacular drive of about 3.5–4 hours. The road is sealed and well maintained, but narrow and winding in places; allow more time than the distance suggests.
InterCity coaches run daily between Greymouth and Queenstown and call at Franz Josef. The village is small enough to walk end to end in twenty minutes; you do not need a car once you are there, though you will want one for trips to Lake Mapourika and the glacier car park.