The Ruling on Combining the Prayers without Shortening Them
Question :
Is it permissible for the traveller to combine (prayers) without shortening them, or to shorten them without combining them?
Answer:
Yes, it is permissible to do so, but shortening them is better than completing them, because Allah, the Most High loves us to accept the licenses which He grants to us, just as He loves that His Decrees be acted upon. So joining the prayers during travelling is better for the traveller, according to what we have mentioned.
Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 2 Page 422