From the Veneto you take the A27 Mestre-Belluno to the final exit of Longarone (Pian di Vedoia), then continue to Pieve di Cadore. Near Auronzo turn off towards Santo Stefano di Cadore and on to Sappada.
Coming from Friuli Venezia Giulia however, follow the A28 Palmanova-Tarvisio and exit at Carnia / Tolmezzo; From here continue on the state highway SS52 which passes through Ovaro, Rigolato Forni Avoltri and on up to Sappada.
The nearest railway station is Calalzo di Cadore from where you can take the bus directly to Sappada and arrive in less than an hour; from the Friuli side get off the train at the Carnia station and go from here by bus to Sappada.
How to get to Sappada
For Those Who want a detailed route to Sappada here are some useful sites:
For Those arriving by train, to train timetables and the purchase of tickets online:
All the timetables for getting to Sappada from the Veneto region, and, in particular, from the Calalzo train station are here:
All times for getting to Sappada from Friuli are here:
Cortina Express service - to / from Sappada to Treviso, Venice, Mestre, Rovigo, Ferrara and Bologna are here: