Is the prayer of one who shortens and completes it during travel valid, such that he prays Dhuhr as four rak'ahs and Asr as two?

The four madhhabs (schools of thought) agreed on the prohibition of traveling on Friday after zawāl (midday/declination of the sun). They differed on it before zawāl: The Hanafis permitted it, the Malikis and Hanbalis disliked it, and the Shafi'is prohibited it except in cases of necessity.

The more cautious approach is not to travel before zawāl unless one prays along the way.

It is permissible for a traveler to shorten and combine prayers, but it is obligatory to pray in full if one prays behind a resident (non-traveler).

Residency is not mandated for the duration mentioned, and it is obligatory to pray in full upon returning to one's place of residence.