This is the 2700th most frequent German word.
gefahren
"Gefahren" means "driven" or "traveled" (past participle of "fahren").
In this sentence, 'gefahren' is the past participle of the verb 'fahren', used with the auxiliary verb 'sein' to denote movement from one place to another by vehicle.
Ich bin gestern über die Grenze nach Österreich gefahren.
I drove across the border to Austria yesterday.
Here, 'gefahren' again represents the completion of movement, implying the train has traveled.
Der Zug ist pünktlich um 14 Uhr gefahren.
The train departed punctually at 2 PM.
This usage differs as 'gefahren' is teamed with 'haben', indicating the subject's control and action in driving.