Whenever a person travels after midday, he should offer the Zuhr prayers and the ride for the journey

Narrated Anas bin Malik:

Whenever the Prophet started the journey before noon, he used to delay the Zuhr prayer till the time for the 'Asr prayer and then he would dismount and pray them together;
and whenever the sun declined before he started the journey he used to offer the Zuhr prayer and then ride (for the journey).

حَدَّثَنَا حَسَّانُ الْوَاسِطِيُّ، قَالَ حَدَّثَنَا الْمُفَضَّلُ بْنُ فَضَالَةَ، عَنْ عُقَيْلٍ، عَنِ ابْنِ شِهَابٍ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه ـ قَالَ كَانَ النَّبِيُّ ﷺ إِذَا ارْتَحَلَ قَبْلَ أَنْ تَزِيغَ الشَّمْسُ أَخَّرَ الظُّهْرَ إِلَى وَقْتِ الْعَصْرِ، ثُمَّ يَجْمَعُ بَيْنَهُمَا، وَإِذَا زَاغَتْ صَلَّى الظُّهْرَ ثُمَّ رَكِبَ.