Exiting Salzburg on the B1 is a tragic bit of the route but you are soon crossing the border into Bavaria, stay with BS21 through Bad Reichenhall. The road follows the Saalach river and then you arrive back in Austria and the B178. The road is well surfaced and was prone to having too many cops on it when I was there in 2004. The view of the mountains ahead as you turn the corners is fantastic. At Lofer bear left onto ther B311 and head for Zell.