Sayyiduna Abu Sa'id (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) said: "When you are three on a journey, let one of you lead the prayer, and the one most entitled to lead is the one who has read the most Qur'an."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5126