Strategies for Crowd Management Safety
Azad Aliyev MEng in Fire Safety, FMP?? PMP?? NEBOSH IG
Troubleshooter | QHSE and Fire Safety Professional | Facility Management | Mega Events Professional
A return to crowded, full capacity sports events, concerts, festivals, and performances seemed unimaginable early on in the COVID-19 pandemic as large venues such as stadiums, arenas, ballparks, and music halls remained closed or operated at a very limited capacity.?However, especially in the US we are now seeing these locations begin to open to larger crowds and even some to full capacity. But, in doing so, we must not overlook the safety challenges that come with the presence of large crowds. On April 30, 2021 what should have been?a celebration turned into a tragedy?as 45 people were killed and over 150 more people were injured at a religious festival.?It was estimated that almost 100,000 people attended the event.?As the celebration ended, attendees began to exit through passages that could not accommodate the crowds.?It was reported that some people may have lost their footing, tripped, and then caused the people behind them to be pushed ahead, crushing people as they were forced ahead by the crowd.
Provisions are in place to ensure the safe and orderly movement of people during an emergency.?When these safety protocols and features are overlooked, it can have a drastic impact on the efficiency of egress response during events such as fire or other related emergencies.?This blog summarizes a few of the code requirements from?NFPA 101, Life Safety Code, which are unique to assembly occupancies with large crowds.
Occupant load
Large assembly venues have a high number of occupants - in some cases, tens of thousands of people - for which they are designed to accommodate safety both entering and egressing the facility. In general,?the occupant load?is determined utilizing factors that are based on how the space is used or is determined as using the maximum probable population of the space under consideration, whichever is greater.?However, in areas of assembly occupancies in excess of 10,000 ft2?(930 m2), the occupant load cannot exceed a density of one person in every 7ft2?(0.65 m2).This occupant load limit exists in order to avoid overcrowding. When overcrowding occurs, walking becomes a shuffle, and then further crowding can lead to a complete “jam point” such that all movement by occupants comes to a stop.
Life Safety Evaluation (LSE)
Where the occupant load of an assembly occupancy exceeds 6,000, a life safety evaluation must be performed. The required life safety evaluation recognizes that fixed protection and suppression systems alone do not ensure safe egress where large numbers of people are present. Expected crowd behavior is part of such an evaluation, as is consideration of techniques to manage any behavioral problems. The evaluation must include an assessment of all the following conditions and related appropriate safety measures:
A new assembly venue subject to the LSE must be assessed prior to construction to ensure that the needed physical elements are part of the design. Also, facility management must be evaluated prior to building occupancy. The LSE provisions help to facilitate better communication among the designers and those who manage the facilities after construction. The goal is to provide managers with safety systems that are compatible with actual building use. Similarly, the LSE provisions for existing assembly occupancies include requirements for building systems and facility management assessments, a life safety narrative, floor plans, engineering analysis and calculations, operational plans, and a systems reference guide.?Extensive details regarding the LSE, including factors that should be considered in an LSE, crowd behavior, and performance-based design approaches can be found within Annex A material in NFPA 101,?Life Safety Code, which should be followed when completing an LSE.
Main Entrance/Exit
Every assembly occupancy, new or existing, is required to have a main entrance/exit. This concept is to accommodate for occupants that are likely to egress the facility though the same door(s)/opening they used to enter it and will be most familiar to them. In some types of new assembly occupancies, the main entrance/exit must accommodate up to two-thirds of the total egress capacity, while in other assembly occupancies it can account for 50 percent.??In assembly occupancies where there is no well-defined main entrance/exit, exits are permitted to be distributed around the perimeter of the building, provided that the total exit width provides not less than 100 percent of the width needed to accommodate the permitted occupant load. This concept acknowledges that some assembly occupancy buildings, such as a large sports arena, have no well-defined main entrance/exit. Occupants enter the building by doors in multiple walls, via one of multiple main entrances/exits. Under emergency egress conditions, all occupants will not attempt to use one common group of doors, because some occupants are familiar with their entrance/exit and others are more familiar with a different one. In such cases, it is the intent that egress width be distributed among the various exits without any one exit being required to provide 50 percent of the egress capacity.
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Auditorium and Arena Floors
In new assembly occupancies where the floor area of?auditoriums?and arenas is used for assembly occupancy activities/events, not less than 50 percent of the occupant load can have means of egress provided without passing through adjacent fixed seating areas. This may occur where a large arena that is usually host to sports games switches to host a concert event and uses the floor area to put additional, temporary seating to accommodate additional occupants. It is intended to reduce the amount of merging and sharing of means of egress by persons in fixed seating areas and those who are forced to travel from the arena floor up into the seating sections to egress the building.??Regardless of where in the assembly occupancy someone might be located, access and egress routes must be maintained so that crowd management, security, and emergency medical personnel are able to reach any individual at any time (floor seating, fixed seating, theater seating, festival seating, etc.), without difficulty.
Emergency Action Plans (EAP)
Emergency Action Plans (EAP) must be provided in assembly occupancies and are a critical component of assuring life safety in buildings.?These plans must include at least a minimum of 18 different items, some of which include the following:
The facility’s EAP must be submitted to the AHJ for review and should be reviewed and updated as required by the AHJ. Following any drill or actual emergency or reported emergency occurring in the building, an after-action report should be prepared by the building owner or designated representative to document the function of the building’s life safety hardware, procedures, and occupant emergency organization.
Crowd Managers
Assembly occupancies must be provided with a minimum of one trained crowd manager or crowd manager supervisor. Where the occupant load exceeds 250, additional trained crowd managers or crowd manager supervisors are to be provided at a ratio of one crowd manager or crowd manager supervisor for every 250 occupants in most facilities.
Those designated as a crowd manager or crowd manager supervisor are required to receive approved training in crowd management techniques, as they?need to clearly understand the required duties and responsibilities specific to the venue’s emergency plan. Training should be comprehensive of all aspects of crowd management including, but not limited to, the specific actions necessary during normal and emergency operations, and include an assessment of people-handling capabilities of a space prior to its use, the identification of hazards, an evaluation of projected levels of occupancy, and the adequacy of means of ingress and egress.?The procedures for providing trained crowd managers must be made part of the written emergency action plan as well.
In conclusion, controlling crowds is a critical aspect of life safety in large assembly occupancy venue.?Designers, owners and facility personnel, as well as inspectors and local Authority Having Jurisdictions all play an important role in ensuring a safe environment for occupants when crowds are present.?With due diligence from all parties, the necessary life safety features for crowd management will not go overlooked.