The Zillertaler höhenstrasse is a toll road free for cyclists. This is a high mountain road that has 5 different access roads and all the climbs up here are quite steep. The first from Ried im Zillertal (551m) is the longest and the one that offers the most varied climb. It is also one of the less steep. The road I took in 2008 starts in Kaltenbach (553m) and is also long and takes in the whole toll road section as well as the many ups and downs. It is quite steep, but not as hard as I had thought upon reading about it.

The steepest two variants starts in Aschau im Zillertal (567m) and in Zell am Ziller (576m) and are both quite hard climbs going more directly to the highest point of the road near Melchboden. These two variants offers long stretches above 10%! Finally the road from Hippach (594m) is the shortest and should have the highest average steepness, but this road is rather evenly steep and a little wider and smoother than most of the others, so it seems not so hard by comparison to the other climbs and is likely the best way to go down.