What should be done if a person who fasts sets out on a journey in Ramadan and nullifies his fasting due to journey? What is the required action if a fasting person breaks their fast due to traveling during Ramadan? How should a person proceed if their fast is nullified by a journey during Ramadan?
A person who is going to go to a place with a travel distance (at least 90 km) during Ramadan may not intend to fast at night. But if one start to travel during the day after making intention to fast, s/he should not nullify fasting if there is no other valid excuse. A continuing worship needs to be completed if there is no valid excuse. However, because traveling is an excuse, if the person breaks his/her fast after starting to travel, kaffarah is not required, but only qada needs to be performed for the day (Ibn Abidin, Radd al-Muhtar, III, 402-405). The fact that Prophet Muhammad (saw) nullified fasting while marching with army to conquer Mecca in a place called al-Kadid (Bukhari, Sawm, 34; Muslim, Siyam, 88) may be considered as a necessity caused by war conditions.
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS