Is it permissible to combine Dhuhr and Asr prayers – and not shorten them – at home before departing for a trip from Abu Dhabi to Dubai after the Dhuhr athan, and does Fatwa No. 28820 apply to this situation?

It is not permissible to combine or shorten prayers before departing from the city from which you are traveling. Once you have left its buildings, it becomes permissible for you to shorten and combine prayers, because combining prayers that are contingent on travel is linked to shortening them. The ruling of a resident traveler does not apply to you as long as you are residing in your country and have not left the entire urban area of the city.