Outbound (adjective)

1. Going out or departing from a place, especially a transportation hub.
2. Traveling in the direction of a destination.
3. Relating to or pertaining to outgoing goods, communications or services.

Origin:

From out- +‎ bound, meaning moving or directed away from a particular place.

Examples:

1. Please arrive at the airport two hours before your outbound flight.
2. The outbound train to New York City is departing from track 7.
3. The outbound mail has already been collected for the day.