Sep 10, 2015

New Paper

New paper on OR based decision support for Hajj crowd management to appear in Interfaces.

The Hajj, the annual Islamic pilgrimage to Makkah in Saudi Arabia, results in one of the largest pedestrian events in  the world. Each year up to four million pilgrims approach the holy sites in the region of Makkah to perform their religious duty. The number of pilgrims is likely to grow substantially over the coming years. The key ritual, the stoning of the devil, is particularly crowded. Until 2006, several stampedes led to thousands of casualties. In the aftermath of a stampede in 2006, the Ministry of Municipal and Rural Affairs of the Kingdom of Saudi Arabia (MOMRA) launched projects costing $7 billion to prevent future stampedes. In particular, MOMRA began the development of an operations research (OR)-based decision support system (ORDSS) for crowd management. ORDSS employs a range of tools from OR, analytics, and crowd dynamics. At its core, it implements a scheduling tool and a real-time video-tracking system. The video-tracking system measures actual infrastructure utilization, and an integrated series of mixed-integer programs and quadratic constrained programs balance capacity utilization by considering preferred stoning times and infrastructure capacities and. In addition, analytics and OR tools in the ORDSS, such as mixed-integer programs, assign pilgrims to trips and stations of a metro system that transport them during the Hajj, support the layout planning of the tent city accommodating the pilgrims, analyze and simulate pilgrim flows, and reschedule pilgrims in high-density situations. The ORDSS provides solutions to MOMRA that enable uncongested and smooth pilgrim flows as well as extensive real-time reporting. OR helped stop the tragic loss of human lives that resulted from the stampedes. From 2007 through this writing, no stampedes have occurred, and the pilgrim experience has been enhanced as a result of reduced waiting times.

The figure shows the separated pilgrim flows toward the Jamarat Bridge (2014). Access to the Jamarat Bridge is separated from egress from the Jamarat Bridge. Source: MOMRA.