When he goes to take the ferry.
Answers 1Add Yours
The script doesn't give us a specific reason..... I would suffice to say the inquiring whether a ticket is one way to a round trip is a general question.
TRUMAN: Hello! Ferry's still here, huh? Thought I might of missed it…
TICKETPERSON: One way or return?
TICKETPERSON: Here you go, sir.
The Truman Show