Abstract
Pilgrimage is one of the five pillars of Islam, which is a duty every Muslim should perform once during his lifetime. Over than two millions Muslims from all the world gather in Makkah for one of the world's largest pilgrimages. All those pilgrims are obligated to be accommodated at Hajj ritual sites, which are the Kaaba, Mina, Arafat and Muzdalifah. With this huge number of pilgrims in the holy city, managing the crowd is a complicated task, especially in the geographical area for the movement of pilgrims, the fixed underlying road-network infrastructure between the different worship places, the annually increasing number of pilgrims and also the short duration of Hajj. As a result of this, huge crowd and difficulties in control have led to fatal accidents among the pilgrims. By the last decade, overcrowding management became a big challenge for the Saudi Arabian authorities and Hajj organizers. Scientists have started research projects to provide several methodologies for crowd monitoring and estimation of its density. In this work, we tried to present a literature review about the Hajj in order to help scientists for future contribution and have lots information about this new field of research.