What should one do who leaves work a little before Asr and arrives home after Maghrib has entered, and should he combine Dhuhr with Asr by way of advanced combination (Jam' Taqdeem)?

If the distance between the two cities is a distance that permits shortening prayers (approximately 83 km from the outskirts of the two cities), then it is permissible for the traveler to combine Dhuhr with Asr in advance (taqdeem). However, if the distance is not so, then the prayer must be performed at its appointed time. If that is not possible, then the driver must be asked to stop for prayer. If there is a fear of missing the group or hardship, then it is permissible to pray in the bus while performing as many of the pillars (rukns) as possible. Some scholars hold the view that combining prayers out of necessity is permissible, provided it does not become a regular habit.