When the Messenger of Allah sat on his camel to go out on a journey, he would say,

Allahu akbar, Allahu akbar, Allahu akbar

اَللهُ أَكْبَرُ اَللهُ أَكْبَرُ اَللهُ أَكْبَرُ

Meaning:
Allah is the greatest.

And then said,

Subuhanalladhee sakkharalana haadha wama kunna lahuu mukrineen, wa’inna ilaa rabbina lamunqaliboon, allahumma innaa nas’aluka fee safarina hadhal birra wath’thaqva waminal ‘amali maa thardha , allahumma havvin ‘alaina safarana hadhaa wa’athvi a’nna bu’dhahu, allahumma anthas saahibu fis’safari wal khaleefathu fil ah’li, allahumma innee a’avoodhzubikka min wa’athaa’is safari wa’kaabathil mandhari wasoo’il munqalabi fil maali wal’ahli.

سُبْ َ ح انَ الَّذِيْ َ س خَّرَ لَنَا هَ ذَا وَمَا كُنَّا لَهُ مُقْرِنِيْنَ وَإِنَّا إِلَى رَبّنَا لَمُنْقَلِبُوْنَ اَللّهُمَّ إِنَّا نَسْأَلُكَ فِي س فَرِنَا هَ ذَا الْبِرَّ وَالتَّقْ وَى وَمِنَ الْعَمَلِ مَا تَرْ َ ضى اَللّهُمَّ هَ وّنْ عَلَيْنَا َ سفَرَنَا هَ ذَا وَاطْوِ عَنَّا بُعْ دَه اَللّهُمَّ أَنْتَ ال َّ صاحِبُ فِي ال َّ س فَرِ وَالْخَلِيْفَةُ فِي الأَهْلِ اَللّهُمَّ إِنّيْ أَعُ وْذُ بِكَ مِنْ وَعْثَاءِا ل َّ س فَرِ وَكَآبَةِ الْمَنْظَرِ وَ ُ س وءِ الْمُنْقَلَبِ فِي الْمَالِ وَالَأهْلِ

Meaning:
Hallowed is He Who subdued for us this (ride) and we were not ourselves powerful enough to use It as a ride, and we are going to return to our Lord. O Allah, we seek virtue and piety from Thee in this journey of ours and the act which pleaseth Thee. O Allah, lighten this journey of ours, and make its distance easy for us. O Allah, Thou art (our) companion during the journey, and guardian of (our) family. O Allah, I seek refuge with Thee from hardships of the journey, gloominess of the sights, and finding of evil changes in property and family on return.
(Muslim 2392)