Route from lake Constance to Southern Switzerland?

[Kieranv]

Hi there, off on a European adventure at the end of the month, heading from Amsterdam down through the black forest and into Switzerland.

I think other than this section the general route is looking decent.

I'm struggling a bit to find a decent route between our stop at Constance and Lucerne/Interlaken where we will be staying next. Does anyone have any recommendations or should we just motorway it until we get to the good stuff?

Cheers
Kieran

P.S. I know most of the high passes will still be shut when we're around Interlaken, I'm sure we'll find something though