1. 1 Techniques of Crowd Management Techniques of Crowd Management

2. 2 Crowd Management and Crowd Control Defined Crowd management is defined as the planned movement and assembly of people. Although the terms crowd management and crowd control are often used interchangeably, there are important differences. 93

3. 3 Crowd Management and Crowd Control Defined Crowd management involves the systematic assessment of all aspects of venue occupancy prior to use. It can be considered an adjunct to the life safety evaluation process, with greater concentration on the possibilities for extreme crowding and its potentially fatal consequences. 93

4. 4 Crowd Management and Crowd Control Defined Crowd management planning includes determination of expected number of occupants of a space, anticipated group behavior, assessment of the adequacy of assembly areas, means of both ingress and egress, processing procedures such as ticket collection and security screening, staffing requirements, and means of communication. 93

5. 5 Crowd Management and Crowd Control Defined Crowd control is defined as the restriction or limitation of group behavior. Crowd control may be part of a crowd management plan or may occur as a reaction to a group problem 93

6. 6 Crowd Management and Crowd Control Defined It can include extreme measures to enforce order, such as the use of force, threat of personal injury, or arrest. It may employ barriers that alter the space available for occupancy and patterns of group movement.93

7. 7 Crowd Composition Crowds can attract participants who come to observe and to enjoy an event peacefully, as well as predators in search of victims and people with other psychological, social, or political agendas.

8. 8 Crowd Composition The crowd provides some with a cover to engage in hostile or aberrant behavior, or as an opportunity for theft, selling drugs, or solicitation. 94

9. 9 Crowd Psychology Psychologists have likened a crowd to a series of intermeshing behavioral cells. Each crowd cell is composed of a small group of surrounding people, with limited personal interaction and communication within it. The members of an individual cell have no broad view of what is occurring in the crowd mass. 94

10. 10 Crowd Psychology A dominant cell member may influence the behavior of others within the cell. There may be cell-to-cell communication, often with the spread of unfounded rumors and misinformation. 94

11. 11 Crowd Psychology Crowd situations show a lack of front- to-back communication. People in the rear of the crowd will continue to press forward, while those in front experience severe distress but are unable to communicate their plight. 94

12. 12 Crowd Psychology This situation is due in part to the differences in pedestrian densities between front and rear ranks of a crowd. Those in the rear are at densities that still permit movement, whereas those in front are immobile and under great pressure. 94

13. 13 Crowd Categories Three general categories of potentially dangerous crowd situations have been identified: (1) critical occupancy, (2) flight response, and (3) craze. All types of crowds, even relatively small gatherings, can quickly become dangerous if not carefully managed. 94

14. 14 Crowd Categories Critical occupancy is the gradual accumulation and overloading of a pedestrian space, beginning at levels below 3 ft 2 /person until it reaches the plan view area of the human body of about 1.3 to 1.5 ft 2

15. 15 Crowd Categories Critical occupancies can occur in transportation terminals during service disruptions, at public events, or at other venues where ingress and assembly are not controlled 94

16. 16 Crowd Categories The flight response occurs where people are fleeing either from a real threat, such as a fire or explosion, or from a perceived, but otherwise nonthreatening, event.

17. 17 Crowd Categories Flight responses may be labeled as panics and stampedes, but closer examination shows that rapid group movement away from the threat was a reasonable reaction 94

18. 18 Crowd Categories Flight response fatalities may occur where egress facilities are overwhelmed by the sudden rush and are restricted or blocked. Flight response incidents may occur due to fire, explosions, power outages, structural failures etc. 94

19. 19 Crowd Categories Flight response fatalities may occur where egress facilities are overwhelmed by the sudden rush and are restricted or blocked. Craze fatalities can occur where ingress facilities such as doors, ticket collection, or other pedestrian movement elements in the path between the crowd and its intended objective are overwhelmed 94

20. 20 CROWD DISASTER MODEL The primary elements involved in crowd disasters have been determined from personal experiences in dense crowds, studies of many major crowd incidents, and basic pedestrian traffic engineering principles.

21. 21 CROWD DISASTER MODEL The model is patterned after classic systems analysis elements of time, space, information, and energy, and modified to form the descriptive acronym FIST 94

22. 22 CROWD DISASTER MODEL When crowd density equals the area of the human body, individual control is lost as one becomes an involuntary part of the mass.

23. 23 CROWD DISASTER MODEL The crowd mass becomes almost fluid, with shock waves propagated through it sufficient to lift people off their feet and propel them distances of 10 ft. or more. 95

24. 24 CROWD DISASTER MODEL Intense crowd pressures, exacerbated by anxiety, can make it difficult to breathe. Compressive asphyxia from these pressures is the most common cause of crowd deaths, not the trampling usually reported in the press. 95

25. 25 CROWD DISASTER MODEL Compressive asphyxia, a condition medically difficult to reverse, has occurred in people as others pile up on them as they fall. The pressures are not due entirely to pushing, but are also the domino effect of people being forced off balance and leaning on those in front. 95

26. 26 CROWD DISASTER MODEL The human shock waves that surge through the crowd are a combination of this domino effect and a collective muscular reflex to obtain breathing space. Persons falling during a crush will have others forced on top of them, pinning them down and if the pile is high enough, causing respiratory failure. 95

27. 27 CROWD DISASTER MODEL Space encompasses all the physical facilities used for the assembly and movement of people. Deficiencies in the capacity and configuration of assembly and movement facilities are considered to be the primary cause of crowd disasters. 95

28. 28 CROWD DISASTER MODEL Time is the duration of the crowding experience. It is a direct determinant of total movement capacity. Crowd incidents may begin with a rapid buildup of people at a point where practical capacity is exceeded and free movement is blocked. 95

29. 29 CROWD DISASTER MODEL During the exit sequence, facilities are used to near maximums, and dense crowding occurs. Time-based strategies can be used to manage the degree of crowding during some events. Major art exhibitions have reduced traffic peaking and venue crowding by time-of-arrival ticketing. 95

30. 30 CROWD DISASTER MODEL Metering is a time-based crowd management and control technique used to control the arrival rate of persons at any “bottleneck” facility with limited capacity.

31. 31 CROWD DISASTER MODEL In California, a form of metering was applied by the Bay Area Rapid Transit system planners at the Oakland stadium pedestrian bridge connection to the adjacent transit station. 95

32. 32 CROWD DISASTER MODEL The bridge was purposely under- designed so that bridge traffic flow rate equaled the passenger loading rate of the transit system trains. This form of crowd management avoids potentially dangerous crowding on transit platforms. 96

33. 33 Festival Seating Events Festival seating events, actually general admission without the formalized control offered by reserved seats and aisles, consistently result in critical occupancy conditions. Fan exuberance combined with extreme densities in front ranks cause most of these incidents. 96

34. 34 Festival Seating Events In June 2000, 9 persons were killed and more than 25 injured as the band Pearl concert in Denmark. It was estimated that 50,000 people had congregated at the Pearl Jam venue. Band members became aware of the crush and implored the audience to step back. sense no danger 96

35. 35 Festival Seating Events It is virtually impossible to reverse a crowd crush in progress by this method because those in front ranks, in the “crush zone,” cannot move, while those in the rear sense no danger. Security staff is relatively ineffective in festival seating events, relegated to standing around the perimeter of the audience, without direct crowd access 96

36. Festival Seating Events Persons becoming ill in a dense crowd must be “surfed” out of the venue, by being passed overhead by the audience to security personnel on the perimeter Venue owners and managers have the responsibility of controlling promoter and entertainer actions, consistent with the venue capabilities and audience safety 96 30

37. 37 Flight Response Incidents Flight response incidents are triggered by fires, explosions, or unusual weather events that are perceived as threatening personal safety. Misinformation has also caused flight response incidents when there is no real threat. 97

38. 38 Flight Response Incidents The DuPont Plaza Hotel fire in San Juan, Puerto Rico, in December 1986 resulted in 98 deaths in the hotel casino. The casino had a double door at the front entrance off the main lobby and a single door at the rear. 97

39. 39 Flight Response Incidents The fire, started by arsonists, began in a ballroom on the other side of a wide stair adjacent to the casino. Hotel staff became aware of the fire shortly after ignition and made futile attempts to extinguish it. 97

40. 40 Flight Response Incidents Had this door opened outward, instead of inward, many lives would have been saved because of its close proximity to the pool area. However, fleeing victims piled up against the door, jamming it shut. Virtually all the victims were found at this door. 97

41. 41 Flight Response Incidents The incident illustrates the importance of rapid communication, and the design and maintenance of viable egress routes. The incident illustrates the importance of rapid communication, and the design and maintenance of viable egress routes.(sprinklers and hard wired smoke detectors) 97

42. 42 Flight Response Incidents In February 2003 a DJ dance at the E2 nightclub in Chicago resulted in 21 dead and 85 injured. Occupancy estimates vary, but a fire department official stated that as many as 1500 persons were on the second floor of the popular club at the time. 97

43. 43 Flight Response Incidents There was an altercation in the club and the promoter’s security personnel used mace pepper spray in an attempt to quell it. The spray permeated the air causing some to choke. Rumors spread that it was a terrorist act using poison gas. 97

44. 44 Flight Response Incidents The bulk of the crowd rushed toward a 54-in. wide stair that connected to the front entrance, exceeding its capacity. Critical occupancy of the stair resulted in a pileup in the 11 ft. by 12 ft. entrance lobby below. 98

45. 45 Craze Incidents The Station Nightclub fire in West Warwick, Rhode Island, also in February 2003, resulted in 100 dead and more than 180 injured. A fire official stated that the nightclub was fully involved within 3 minutes. For a brief moment some watched the fire, thinking it was part of the act, but then quickly realized the danger. 98

46. 46 Craze Incidents Most headed for the front entrance, the typical escape route in many incidents, jamming it and blocking orderly egress. Those outside tried to extricate victims in the pileup, succeeding in rescuing some. 98

47. 47 Craze Incidents A power failure resulted in 45 deaths, 27 of them children, in 1981 at the Tower in New Delhi, India. The 800- year-old tower is a popular tourist attraction and museum.

48. 48 Craze Incidents A blackout, combined with unfounded cries that the tower was falling, triggered a sudden flight of 300 to 400 people. The fatalities occurred on a narrow tower stair.98

49. 49 Craze Incidents The Who concert disaster in December 1979 at the Cincinnati, Ohio, Coliseum is an example of a craze.11 A crowd of 18,000 young fans was gathered outside the Coliseum waiting to enter this general admission event. All seats were on a competitive first in– best seat basis. 98

50. 50 Craze Incidents The opening of the gates was delayed until shortly before the scheduled time of the performance. The warmup band started playing, and the fans thought the concert had begun. Only two doors were open to permit entry. The crowd rush and pressures resulted in 11 deaths. 99

51. 51 CROWD MANAGEMENT PHASES There are three phases in which crowd management principles should be applied: (1) venue design, (2) pre-event planning, (3) and the event itself, including ingress and egress.

52. 52 Venue Design Many architects and engineers give minimal attention to the movement of people in initial venue design beyond that required for compliance with local building code or permit requirements. 99

53. 53 Venue Design Designing for crowd management requires that the projected maximum occupancy of a space, combined with expected behavioral factors, be correlated with the traffic processing capabilities of all corridors, stairs, ramps, escalators, elevators, and other related facilities. 100

54. 54 Venue Design A good management technique is to develop a circulation “tree” diagram, or schematic pedestrian traffic flow plan, to show how the expected occupancy of a space will be distributed among its various elements. 100

55. 55 Venue Design The circulation diagram is a useful tool for assessing actual venue performance under various conditions and pinpointing areas that are not performing as expected. The circulation plan can be further refined by using computer simulations of pedestrian traffic movement 100

56. 56 Venue Design The influence of external facilities on the volume and patterns of movement within a venue must be considered. For example, the concentration of parking or transit operations on one side of a stadium will focus internal movement toward that side, resulting in unbalanced traffic demands. 100

57. 57 Venue Design Pressure point hazards along movement pathways must be avoided. Pressure points are locations where a right angle change in the normal direction of movement Crowd pressures at such locations may result in people being pushed over guardrails or down stairs, or in the structural failure of the guardrails. 101

58. 58 Venue Design The crowd management center requires full communications integration with all crowd management staff; local police, fire, and emergency medical services; and any on-site radio or television media staff. Provision should be made for location of extra-large format TV screens as a multipurpose means of communication. 101

59. 59 Venue Design Backup standby power for lighting and communications must be included in the design. The NewDelhi Tower blackout crowd incident is an example of the confusion that can result from a lighting and communications failure. 101

60. 60 Venue Design Many venues accommodate the population equivalent of a medium-sized city, requiring that the medical center be fully equipped to provide immediate skilled response to cardiac cases, spinal injury cases, and other similar emergencies. 101

61. 61 Pre-Event Planning General admission events should be avoided because they introduce competition within groups to obtain favorable viewing positions. Reserved seating has been combined with festival seating areas to maximize attendance at some events. 101

62. 62 Pre-Event Planning This combination can result in competition by those in reserved seating to move closer to the performers in the festival viewing area. 101

63. 63 Pre-Event Planning A simple pass-through gate with no information exchange required can accommodate up to 60 patrons per minute. This rate will be cut in half if the ticket processor has to read and tear the ticket.

64. Pre-Event Planning When patrons require more involved instructions or information, entry processing rates can drop to 6 per minute. 101 64

65. 65 Pre-Event Planning During a study of door egress rates at a 16,000 seat arena the author observed that a number of doors were chained and locked during the event as a means of controlling gate crashing. Crowd densities during a sudden emergency egress would make it impossible for the staff to gain access to these doors to unlock them. 101

66. 66 The Event Communication failures are a common component of virtually all serious crowd incidents. Accurate and timely information is necessary to assure an appropriate response to developing situations before they reach critical phases.

67. 67 The Event Public address systems should be capable of reaching all areas of the venue, and instructions should be accurately phrased and understandable. Closed-circuit TV surveillance cameras should be situated to cover all blind spots, as well as a wide view of the event venue.

68. 68 The Event Crowd managers should know how to communicate with first responders in an emergency and what their radio frequencies are. This information could prove valuable in assuring that appropriate equipment and numbers and type of personnel are dispatched to the site.