Depending on where you stay in Adigrat, a free airport shuttle could include a round trip to and from the airport or it could be just a one-way shuttle to your hotel.
How often will the shuttle run?
It depends on where you choose to stay in Adigrat. Some hotels have shuttles that run at regular intervals day and night; others require advanced reservations for custom departures and pick-ups. It's important to check the hotel's policy on Expedia before you book.