The literature review and interviews for this project indicated that until emergency evacuation plans for towns and cities have focused mainly on the movement of people in private vehicles. Little mention was found of pedestrians (other than as building evacuees) in the past research on emergency evacuations. The evidence indicated that little attention has been given to instructions and routing for people evacuating a section of an urban area on foot. With the public’s reactions to the 9/11 attacks came news service photographs and accounts of people leaving office buildings in New York City and Washington, D.C., and not necessarily using a private vehicle or mass transit to leave the city. Many are thought to have walked long distances if it was necessary to arrive at their preferred destination, usually their residence. Since 9/11, some cities have begun to consider pedestrians in their evacuation plans, such as those developed for Cleveland, Ohio, and Charlotte-Mecklenburg, North Carolina (see Section 5.3.2 above).
During this research, discussions with 23 persons representing an array of disciplines from transportation and public safety practitioners to social and behavioral science researchers revealed a range of issues to be addressed if emergency evacuations from big cities are expected to involve large numbers of both private vehicles and pedestrians. Transportation officials in particular voiced concerns about whether pedestrians can be kept safe, since they cannot be managed and channeled as easily as can vehicles. This was at least partially based on having witnessed pedestrians walking in the roadway among vehicles in some locations in New York City and Washington D.C. Public safety and behavioral science experts generally agreed that it can be difficult to deter pedestrians from taking direct routes to destinations, or to deny them access to a familiar route. The social scientist experts in disaster behavior are confident that pedestrian evacuees will behave in an orderly adaptive manner, including looking out for and helping each other and staying out of the way of emergency responders.
Most emergency response experts acknowledge that in any emergency or sudden threat situation, people need and want information. For that information to result in appropriate protective behavior, what people are told at any given time must be relevant to their decision-making about appropriate action, even if it is not a complete picture of the emergency or a threat. Research findings on emergency evacuation behavior and management of special events suggest that people leaving buildings are likely to move away from where they emerge from buildings if they have an indication of which direction or directions are appropriate and safe. Planning for pedestrians in emergency evacuations must address how to determine the appropriate direction under the circumstances and how this guidance is provided to those who are evacuating. A major issue for consideration is that of what strategy for evacuating a major downtown area will result in the least harm to the evacuees. Dilemmas will emerge. For example, when gridlocked traffic conditions curtail mobility of drivers; walking may be faster in general but not possible for certain people; being in the open air prolongs exposure for those walking along distance. The use of special evacuation transit may promise faster and safer evacuation, but the capacity of the buses not adequate for a sudden surge of evacuees, leaving many evacuees waiting for carriers to drop off evacuees and return to the downtown area for more.
Up to this time, evacuations from large, highly concentrated cities similar to New York City are too few in number to provide much information to go on for knowing what to expect. Systematic study of large-scale pedestrian evacuation in U.S. cities still is needed to better understand how pedestrian evacuees react to various types of settings, situations, and instructions. Some of the participants in the study remarked that on 9/11 and during the extensive August 2003 blackout in the northeastern states, the time-concentrated exodus by the urban workers who lived elsewhere was essentially an extremely heavy end-of-the-day commute. That is, people going home don’t just move as far as is necessary to be safe, but instead continue on to their residence. They know their destination, which is likely to be at some distance from the perimeter of the area defined as dangerous; they work out a way to get there under the circumstances. This pattern of workers evacuating and heading home, even on foot, raised questions about how far and by what routes and transportation modes urban evacuees will travel, and what services they will need or want along the way. Even less well understood is the likely behavior of people who live and work in the downtown area, and who may be car-less by choice. They may make the decision to evacuate, leaving their home and possessions temporarily, but may not have to travel very far to come to a part of the city that is not being evacuated.
Transportation managers and researchers need to be prepared to conduct studies following the next case of a major metropolitan evacuation from a no-notice event. FHWA sponsored relatively detailed case studies of the 2001 and 2003 evacuations from New York City and Washington, D.C., but the objective of the case studies was to determine the disruptions to transportation activities and adjustments made by the transportation agencies. Consequently, the large number of people evacuating on foot was more a finding than a focus of the inquiries.
Disaster researchers from the behavioral disciplines tend to be skeptical of emergency plans that specify what the evacuation planners see as the best thing for people to do. Social scientist disaster researchers advocate for emergency evacuation planning that takes into account how people are likely to respond based on what is known about social behavior in threatening situations and in response to warnings. With the exception of the 9/11 events, there have been no large-scale evacuations in major U.S. metropolitan areas precipitated by a sudden “no-notice” event or threat. Even in reports of the response during the 9/11 events, there is little information about whether pedestrian evacuees were given any instruction by authorities as to evacuation routes and if so, how the evacuees responded to instructions or advice.
Past research from other types of disaster cases indicates that in the immediate post-impact stage, people tend to be reasonable and adaptive. They also will be cooperative with authorities when they think they have received adequate information about the danger and appropriate protective actions. Case studies of large-scale urban evacuation are needed to what the specific decisions and actions are in these urban contexts. The most commonly observed response and evacuation behavior has been in the context of the traditionally structured environment of smaller cities and towns. Persons living in high density urban environments and more used to the congestion and transportation alternatives can be expected to collectively adjust their behavior to that context.36 The unanticipated emergence of pedestrian evacuees in New York City and Washington, D.C., in the face of the 9/11 situation provides some evidence that this may be one of the adaptations to that context. Indeed, urban dwellers may have learned from their observations of these events. Not only was evacuating on foot “publicized” through media accounts as an option during urban evacuation events, but the delays described because of the initially gridlocked traffic may result in other urban dwellers considering options other than driving, should the need to evacuate from a downtown area occur. Circumstances that differ in many high density downtown areas, compared to smaller cities, include better walking facilities, more mass transit options, and a greater likelihood that a large proportion of the evacuees are headed home, instead of to some unfamiliar location to wait out the evacuation situation
At the moment of this report, there are two major opportunities for gathering more systematic detail about urban evacuations involving pedestrian evacuees: the last case and the next one. The most recent cases would be that of people leaving Lower Manhattan after it became evident that the planes hitting the World Trade Center towers were no accident, and the government and other office workers voluntarily leaving downtown Washington, D.C., as news of the attacks emerged. Various types of research were found in relation to New York City, but none was identified that provided an overview of the decision points of the pedestrian evacuees or the interactions between pedestrians and the agency officials with roles related to facilitating the temporary evacuations. Now that issues have been raised about pedestrian evacuation, preparations should be made for research on the next case as well. General areas of recommended research about the management and accommodation of pedestrians from these two past cases and in the next no-notice urban evacuation follow.
In order to better understand the nature of pedestrian evacuations in U.S. cities in response to a no-notice event it will be necessary to employ various research techniques to glean further information from the 9/11 evacuations of Lower Manhattan in New York City and Washington, D.C. While these two evacuation examples are several years old and officials directly involved likely to have dispersed to some extent, the scarcity of such events as opportunities to pursue the topic of pedestrian evacuation lend value to such research. This research was completed before the September 2005 hurricane season.
Nonetheless, the evacuations in relation to warnings about the approaching Hurricanes Katrina and Rita in 2005 do not seem to provide examples needed for understanding the issues raised for research on no-notice evacuations. For example, a telephone survey conducted by Harvard Medical School37 found that, as typical of hurricane evacuations, about 75% of the respondents from the New Orleans Metropolitan Area had evacuated at some point before the hurricane made landfall. Of the 25% of the sample who said they had not evacuated, about 40% of them said they did not evacuate because they felt the storm would not be that bad, while another 40% said they did not evacuate because of a lack of money. The subsequent and unanticipated flooding from the levee failures clearly called into view issues relating to a need for being prepared to provide specialized transportation assistance in urban evacuations. Once the unanticipated flooding started, official activities are better characterized as rescue for people who had remained in their neighborhoods and institutions rather than as an evacuation situation. As an example of research approaches and questions for examining the 9/11 evacuations, the approaches to consider include systematic surveys of individual behavior, interviews with agency officials, in particular law enforcement and transportation agencies, and compilation of private and public video recordings from the morning of 9/11, such as the following:
If transportation and emergency management agencies view as high priority the possession of better information on which to base planning assumptions about evacuations with large numbers of people on foot as well as in vehicles, it is important that the decision to collect this information be made in advance of the next event. Timely post-disaster research calls for consideration of how to make resources immediately available for data collection. Examples of this type of contingent research funding in past decades can be found with the National Science Foundation, the National Research Council, and the National Institute of Mental Health. Needless to say, the more resources that can be made available, the more extensively and systematically the question of pedestrian evacuation, as a phenomenon or an official strategy, can be studied using the various research approaches and data sources.
Agencies responsible for urban emergency evacuations need to consider what types of information are most important in their view to be obtained from the next evacuation of a highly concentrated metropolitan area in response to a no-notice event or credible threat. Information collected within weeks or months of the event is less likely to have suffered distortions that inevitably creep into accounts provided long after the event. Research techniques and questions appropriate for this task are the same as those suggested for research on the 9/11 evacuations, including the following:
In summary, the main intent of this study was to try to identify practices or ideas that transportation managers and public safety agencies were planning or maybe had actually used, to ensure that people evacuating on foot and people evacuating in vehicles did not hamper each others’ mobility in relation to a safe and preferred destination.
Practitioners expressed concern that they had not given adequate thought to planning for large numbers of people evacuating on foot, now that there was some indication this may occur in large cities. The discussions with the practitioners also indicated they believe the usual techniques for traffic congestion management can be used. However, they assert that emergency planners need to focus much more attention during preparedness planning on evacuation scenarios that provide planning assumptions for pedestrian evacuation.38 The public safety practitioners emphasize that the basis of effective emergency response of any type is the development of close and continuous working relationships across agencies. The transportation practitioners add to this that the transportation agencies have traditionally responded based on decisions and directives of others. Among other things, the development of intelligent transportation systems (ITS) now put them in the position of being able to make major contributions of information during disaster response and the means to provide information to the public, and especially travelers. Transportation agencies also are increasingly using public education campaigns to familiarize drivers and riders with options and information sources. These ITS assets and education campaigns can be capitalized on for the development of information sharing and dissemination for managing both traffic and pedestrians during major disruptive events. Transportation officials need to have greater participation during city evacuation planning and to provide a more proactive presence during emergencies.
In conclusion, based on the information collected for this report, it seems reasonable to say that the factors associated with the emergence of a large scale pedestrian evacuation from a section of a large U.S. city are not as yet very well understood. Since 9/11 several U.S. cities have begun to incorporate the possibility of people choosing or needing to leave a downtown area on foot in preference to driving. Evacuation planners view as credible the image of the almost impenetrable traffic gridlock that can occur if downtown populations suddenly begin to leave the city because of a no-notice event or threat.
At the same time, discussions with transportation and response practitioners and disaster researchers raised the issue of considering pedestrian evacuation as the quickest option for getting large numbers of people away from a dangerous area in a concentrated urban area. Thus, further research is needed to help clarify the planning assumptions for managing a metropolitan-based pedestrian evacuation. Pedestrian evacuation can be seen as a phenomenon that responders should consider in order to be prepared for the potential that large numbers of people may decide to evacuate on foot, along with vehicle traffic. On the other hand, evacuation planners may want to consider under what circumstances the deliberate implementation of a pedestrian evacuation might be a preferred and feasible strategy for most quickly getting the largest number of people out of harm’s way.