MARTA transit train station is inside of ATL Hartsfield Jackson Airport. Train picks up every 15 min and is a 20-minute direct ride from Airport-Buckhead. You may take the Gold Line toward Doraville station. The closest stop tp the JW Marriott hotel is the Lenox stop (only available on the Gold Line), not the Buckhead stop which is available on the Red Line. The Lenox stop on the Gold Line is directly across the street from JW Marriott hotel.