Shafaqna (International Shia News Agency) – Ayatollah Khamenei answered a question regarding distance. According to Shafaqna the question and answer are as follows:
Starting-point for calculating Shar‘ī Travel Distance
Question : I carry my wife and two daughters almost every weekend to their school outside London. Our home is inside London. The distance from our home to the boundary of London is 7.5 miles. But, before getting out of London’s boundaries, we must drive for another 13.5 miles around the city and from the boundaries to the school it is 4.5 miles, i.e. we must drive a total of 25.5 miles from home to school. Should I pray qas’r there? Or shall I follow caution and offer prayer in both full and qas’r forms?
Answer : The distance traveled inside London or that in the gap between city boundaries and tarkhkhuṣ limit is not included in the traveling distance. Therefore, since the distance of 4.5 miles from city boundaries to destination is less than shar‘ī distance, you have to offer full prayer there.