Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) says that the Prophet (peace and blessings be upon him) said: "When three men are on a journey, one of them should lead them in prayer, and the one among them most entitled to lead is the one who has read the most of the Qur'an."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5288