Combining the Prayers when Travelling
Some people, if they for example, from Riyadh to Al-Kharj, that is, approximately eighty kilometres, combine the prayers while they are on the road. Is this action of theirs correct?
Yes, it is permissible for the traveller to combine the prayers, or to offer them separately at their stated times. However, if he staying somewhere, then it is better for him to offer every prayer separately, at its stated time, as this is what the Prophet (sallallaahu alaihi wa sallam) did in Mina and in the Farewell Pilgrimage.
Shaykh `Abdul-`Azeez Bin Baz
Fatawa Islamiyah Vol. 2 Page 425