The Prayer of the Traveller behind the Regular Imam
Question :
Is it better for travellers to perform the Zuhr prayer with the regular Imam in the mosque, then offer the 'Asr prayer combined with it after that, or should they perform Zuhr and 'Asr without waiting for the Imam?
Answer:
If there is no difficulty for them in waiting for the regular Imam, then it is better for them to pray with him in the mosque, because there is more reward in this prayer due to the larger number of worshippers and the waiting, which is a form of prayer. However, if this is difficult for them, then they are permitted to offer the Zuhr and Asr prayers together, shortening them and without waiting for the regular Imam.
Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 2 Page 423