Prayer: Do weekly student or work travellers shorten prayers after a break, or pray full from the first resumed trip?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: Do weekly student or work travellers shorten prayers after a break, or pray full from the first resumed trip?

English:

Question #650:

What rule applies to university students who travel at least two days a week for the sake of studying, or to employees who travel weekly to their jobs? Given that they travel every week but occasionally stay in their watan for a month during college or office vacations and they do not travel during this period, will their prayers be shortened during the first journey (according to the rule), when they resume traveling, and be said in full after it? What is the rule if he has traveled for entertainment before this work travel?

Answer #650:

As far as prayer and fast during a travel for studying are concerned, the rule is based on caution, whether their trip is weekly or daily. As for a person who travels for job, whether official or private, if he travels to and fro between his watan/residence and his workplace at least once every ten days, he should perform his prayers in full and his fasting is also valid. However, if he stays for ten days in his watan or in another place, between two trips to work, during the first work trip after the ten days he should shorten the prayers and will his fast is not valid. However, if, before this work trip, he goes for a private trip, he should offer shortened prayers during this private trip. As far as the work trip after the latter trip is concerned, he should not neglect the caution by offering both full and shortened prayers

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer