How Scary is it!

We have used the tunnel many times now but I am keen to drive the pass sometime but my wife does not like 'dangerous' roads with no edges! The road on the pass does not LOOK bad but are there side walls all along it or are there just open edges to the sides?

How much longer is it than the tunnel? I've heard it takes an extra 4 hours which seems unlikely! Any ideas?

Hope to try it in June next year

Thanks

Alistair