In Islam, the Hajj is an annual pilgrimage that starts on 9th August, a significant religious event for Muslims. The pilgrimage involves following the Prophet Muhammad's journey to Mecca back in 632AD for Muslims to cleanse themselves of sin. This religious experience should be carried out by every Muslim who has the physical, mental, and financial capability at least once in their life.

Over the past 19 years, on average, 2,362,528 Muslims have attended Mecca. To put this in perspective, Mecca's population as of 2019 is 2,004,888. Essentially, Mecca more than doubles in population over the six-day pilgrimage window every year. With so many people comes a lot of challenges and risks — so, how is a mass gathering like the Hajj made possible and safe?

The figures

The amount of people participating in this pilgrimage has increased steadily between the years 1999 and 2012, resulting in the highest-ever number of pilgrims in 2012 at 3,161,573. This led to quotas and restrictions being placed per country by the Saudi government — and 1 million fewer pilgrims in 2013.

Nevertheless, even though restrictions were put in place, there are still hazards of large crowds. Stampedes had happened during the Hajj before, but the worst occurred in 2015. The resulting questions and concerns surrounding the event led to another fall in numbers in 2016 as many chose to boycott the gathering.

After this boycott, numbers of pilgrims rose.. It is predicted that by 2030, numbers could reach 6 million. With this in mind, how do authorities manage such a colossal number of people?

The challenges

With these figures, the most apparent risk is stampedes or people being crushed. In such events, those present are unable to control their movements due to being pushed and lifted by pressure-ripples of a tightly packed crowd. This means density numbers need to be managed to fine detail.

Risk management involves crowd simulation software. Maher Saleh Abolkhour from the King Abdul Aziz University used such software to analyze and predict the movement of crowds at the Hajj.

Management

The Al-Masjid al-Haram is an open area in the pilgrimage. Using crowd simulation software, Maher was able to re-run the simulation of a huge crowd in this space, recording predicted behavior and the rise and fall of crowd density. This, in turn, allowed Maher to create different models, moving gates and fences and re-running the simulation to see how these changes would affect crowd behavior.

To improve the route for crowd safety, Jamarat Bridge, home to the stoning of devil rituals, was redesigned. In 2016, 308 escalators were installed, alongside six-passenger lifts, two ambulance elevators, and two helipad elevators.

The Saudi government introduced a fleet of ambulances dedicated to the pilgrimage. According to reports by the Independent, each ambulance is considered to be its own intensive-care unit.

As the Hajj is a significant part of a Muslim's religion, it's certainly an improvement to see engineering, research, and software stimulation ensuring the safety of pilgrims. With figures expected to rise, it's important that the route is made safe for all of those planning to attend.