By shared shuttle bus
Minivan to be shared with other passengers (up to 8 persons)
Duration: Approx. 120 minutes
Website: goopti.com

By Bus + Train
Regional trains from "Treviso Centro" to "Trieste Centrale" (main railway station)
trains leave every 15 min app.
Duration: 4 hours
Website: https://www.trevisoairport.it/en/ - https://www.trenitalia.com/en.html