Q. Am I a musafir if I leave home, go 30 miles, then in the afternoon, I decided to go an additional 40 miles. In total, I traveled 60 miles from my home; am I a musafir?
A. An individual traveling 48 miles or more is considered a musafir. However, in your case you are not a musafir due to the following:
1) It was only upon completing your first 30 miles that you decided to go on for an added 40 miles.
2) Had you made your intention from the outset that you were going to travel 70 miles away from the boundaries of your city, then indeed you have qualified as being a musafir.
3) In your case, since you did not intend the additional 40 miles from its outset, you would not be allowed to perform Qasr salah. You also would not be considered a musafir.
(In the future, if you can make your intention at the beginning, you won’t have to be in this dilemma.)
Allah certainly knows best.