From POLAND, EASTERN AUSTRIA, CZECH REPUBLIC, SLOVAKIA, HUNGARY
Westautobahn Wien - Salzburg (A 1), Wals-Lofer exit to the border ..., then via Bad Reichenhall to cross the border at Steinpaß, Lofer, direction Zell am See.
Please note that a Vignette is obligatory on Austrian motorways!!!
 

or alternatively

Westautobahn Wien - Salzburg (A 1) to Knoten Salzburg, then Tauernautobahn (A 10) direction Villach, Knoten Bischofshofen, to Pinzgauer Bundesstraße B 311 direction Zell am See.

A Vignette is obligatory on Austrian motorways!!!

From Germany:
Autobahn München - Salzburg (A8) to Siegsdorf exit. Then Inzell direction. Drive up to junction and take Lofer direction. Steinpaß (border crossing), Lofer direction. Saalfelden and then to Zell am See .

Vignette is not necessary

From Italy, Slovenia, Croatia (Villach)
Tauernautobahn Villach - Salzburg (A10), Knoten Bischofshofen, then take Pinzgauer Bundesstraße B 311, direction Zell am See, Maishofen, Saalbach Hinterglemm.

or alternatively

Tauernautobahn Villach - Salzburg (A10), to Spittal then exit to Autoverladung Mallnitz – Böckstein, then take Pinzgauer Bundesstraße B 311 direction Zell am See, Maishofen, Saalbach Hinterglemm.

From Italy  (Brenner)
Brennerautobahn (A 13) direction Innsbruck, exit Innsbruck Ost, the to Inntalautobahn (A 12) direction Wörgl, Wörgl West exit, then take Pinzgauer Bundesstraße 312 to Saalfelden, Maishofen, Saalbach Hinterglemm.

By train:
Please contact ÖBB for timetable details.

By plane:
The nearest airport is in Salzburg. Salzburg is destination of all major airlines.