Daily flights by Alitalia, Ryanair, Lufthansa, JAT, Air Dolomiti, Bellair connect major Italian and European cities to the Ronchi dei Legionari Airport (TRS).
From the airport to the railway station of Trieste (45 min.) you can either take Bus line 51 (Airport Bus 51) or a taxi.
The bus stops are outside the airport terminal building. Bus tickets can be purchased at the post office on the ground floor or from the automatic machine at the arrivals hall.
Airport Bus 51 timetable: http://www.aptgorizia.it/cms/data/orari/files/linea_e51_resource_orig.pdf.
From Venezia airport (VCE), ATVO buses take passengers to Venezia Mestre Railway station (25 min.). From Mestre station you reach Trieste by train in about 1h 50 min.
ATVO timetable: http://www.atvo.it/index.php?lang=en&area=23&menuid=35
From both ariports you can also use the Science-Bus Service