National Academies Press: OpenBook

Transportation's Role in Emergency Evacuation and Reentry (2009)

Chapter: Appendix B Emergency Management Roles and Processes in Evacuation

« Previous: Appendix A Emerging Knowledge and Technologies
Page 85
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 85
Page 86
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 86
Page 87
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 87
Page 88
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 88
Page 89
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 89
Page 90
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 90
Page 91
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 91
Page 92
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 92
Page 93
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 93
Page 94
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 94
Page 95
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 95
Page 96
Suggested Citation:"Appendix B Emergency Management Roles and Processes in Evacuation ." National Academies of Sciences, Engineering, and Medicine. 2009. Transportation's Role in Emergency Evacuation and Reentry. Washington, DC: The National Academies Press. doi: 10.17226/14222.
×
Page 96

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

85 APPENDIX B EMERGENCY MANAGEMENT ROLES AND PROCESSES IN EVACUATION This appendix summarizes and describes evacuation planning and management practices and the roles of processes used by emergency management agencies during an evacuation. It includes an example illustration of one state-level emergency management agency’s process in preparing for the issuance of a mass evacuation order. Although the information presented here focuses on hurricane-related mass evacuations, the hazard for which the greatest amount of information on mass evacuation planning and management is currently available, other hazards are also discussed. EMERGENCY MANAGEMENT PROCESSES AND SYSTEMS Although the evacuations that receive the most attention are those that involve hundreds of thousands or millions of people, the reality is that the vast majority of evacuations are much smaller local events that involve less than 5,000 people. As such, evacuations are typically ordered and managed by local officials with relatively little involvement from transportation agencies. Even million-person mass evacuations for wildfires and hurricanes start as local events in which evacuations of threatened areas can begin on neighborhood-by-neighborhood bases. When an evacuation grows to include mass amounts of people over multiple counties (or states), agencies at the state-level become much more involved in the process. Although federal agencies like FEMA have been involved in some aspects of prior evacuations, the federal role is typically limited to providing assistance to state and local officials as the conditions of the emergency surpass local resources and capabilities. Historically, FEMA has not planned or managed evacuations. Since Hurricanes Katrina and Rita, however, FEMA has taken a more active role in pre- evacuation planning. In some hurricane-threatened locations, state emergency management agencies even have pre-scripted missions for FEMA and FEMA maintains operational elements within state and local emergency management offices. The following sections highlight several of the key components of emergency management processes and systems. The discussion is generally presented in a top-down order, beginning with the National Incident Management System (NIMS) which has established a national management framework to plan for and respond to emergency incidents. Also included are summaries of the FEMA emergency management planning and response processes. National Incident Management System Following the terrorist attacks of 2001 and the creation of the US Department of Homeland Security (DHS), the federal government initiated the development of a standardized, structured framework to coordinate emergency preparedness and incident management planning and operations for governmental and nongovermental agencies across federal, state, and local levels. The framework, known as NIMS, was

86 released by DHS March 1, 2004 (FEMA 2006). By presidential directive, all federal agencies are now required to adopt NIMS and to use it in their domestic incident management and emergency prevention, preparedness, response, recovery and mitigation programs and activities. The directive also required Federal departments to make adoption of NIMS by state, tribal, and local organizations a condition for Federal preparedness assistance beginning in 2005. In addition, all state, tribal, and local emergency personnel with a direct role in emergency preparedness, incident management or response were required to certify themselves as NIMS-compliant by October 2006. The NIMS system was developed to provide a consistent nationwide template to enable federal, state, local, and tribal governments and private-sector and nongovernmental organizations to work together effectively and efficiently to prepare for, prevent, respond to, and recover from domestic incidents, regardless of cause, size, or complexity, including acts of catastrophic terrorism. The NIMS report (FEMA 2006) establishes its basic elements and provides mechanisms for the further development and refinement of supporting national standards, guidelines, protocols, systems, and technologies. It integrates best practices that have proven effective over the years into a comprehensive framework for use by incident management organizations in an all-hazards context (terrorist attacks, natural disasters, and other emergencies) nationwide. It also establishes the mechanisms necessary to leverage new technologies and adopt new approaches that will enable continuous refinement of NIMS over time. It was also developed through a collaborative, intergovernmental partnership with significant input from the incident management functional disciplines, the private sector, and nongovernmental organizations. The NIMS standardized incident command and management structures are based on three key organizational systems, including (FEMA 2006): • The Incident Command System • Multi-agency Coordination (MAC) System • Public Information Systems Within NIMS, preparedness is operationally focused on establishing guidelines, protocols, and standards for planning, training and exercises, personnel qualification and certification, equipment certification, and publication management. NIMS requires incident management organizations to ensure that effective interoperable communications and information management processes, procedures and systems exist to support a wide variety of incident management activities across agencies and jurisdictions (FEMA 2006).

87 Emergency Management Planning Process In preparing transportation systems for emergencies it is helpful to understand the emergency management planning process. This process is typically reflected within the five areas of prevention, mitigation, preparedness, response, and recovery. Although the role of transportation has tended to be concentrated within the preparedness and response stages of the process, its role has grown within both mitigation and recovery. Mitigation The mitigation step of the emergency planning process involves activities that are undertaken to develop systems and measures that seek to eliminate or reduce the likelihood of damage or impacts in the event of a hazard. Although the structures and systems within the built environment are purposefully designed and constructed to withstand various levels of destructive threat, the real-world includes numerous conditions that can exceed these expectations. Such was the case with the construction of the levees in New Orleans and structural design of the World Trade Center buildings. It is for these reasons that evacuation is necessary. In some areas of the world evacuation is not an option because there is no adequately safe location from wind or flooding and/or no means by which to move there. In these areas buildings are often designed and built stronger to resist wind or built higher above the ground to resist flooding. Such techniques are certainly common in the US as well. In some locations “vertical evacuation” can be used as a protective action in which people seek shelter in the upper floors of building designed specifically for such purposes. Although such techniques are simple and reduce the need for highway evacuations, they can add significant costs to construction. Often, property owners in the US find it more cost effective to build to a lower threat standard (for hurricane hazards a Category 3 level storm, for example), then purchase insurance to cover losses in the less likely situation that a worse event (like a Category 4 or 5 storm) impacts a structure. Preparedness Preparedness activities involve the development of emergency plans (like those for evacuation) and set frameworks for decision-making; designate agency roles and responsibilities, implement communication systems and protocols; and develop emergency training and drills to maintain readiness; and revise and update plans. In terms of the role of transportation in preparedness, this is an area in which agencies like DOTs and DPWs have significant involvement. One illustration of this has taken place in Louisiana where a working group involving members of Louisiana’s Department of Transportation & Development

88 (LaDOTD), the Governor’s Office of Homeland Security and Emergency Preparedness (GOHSEP), and the State Police (LSP) worked to identify State emergency evacuation routes that could be used by each of these departments and the general public for disaster situations, including chemical spills, ice storms, floods, nuclear leaks, hurricanes, etc (LaDOTD 2008a and Wolshon et al. 2006). One of the outcomes of the process was the development of the southeast Louisiana regional evacuation plan that utilizes contraflow, road closures, and the phasing of evacuation orders (LaDOTD 2008b). When used for the first time for Hurricane Katrina in 2005, the plan showed a significant improvement over prior evacuations (Wolshon and McArdle 2008). Transportation preparedness activities have also included the development and distribution of evacuation route maps and the identification and planning of transit services for assisted evacuees. Response Activities in the response step of the process include the mobilization and implementation of first responders and emergency support staff; the allocation of resources at the disaster locations; the issuance of evacuation orders; and carrying out its implementation. In recent past evacuations transportation agencies have supported these types of response activities by supplying barricades and other control devices and support staff necessary to implement road closures and contraflow operations. Recovery activities seek to return evacuees to areas affected by the emergency and return conditions to normal operations. Transportation agencies have played key recovery roles in several recent emergencies. In Louisiana, for example, the LaDOTD was heavily involved in the immediate response to the flooding of New Orleans because it was the agency responsible for the maintenance of the state levee system and it had equipment, personnel, and emergency contracting mechanisms in place to respond immediately to the situation and make initial closures to the damaged levees. In several recent instances transportation agencies have also played key roles in disaster recovery by repairing damaged roads and bridges to permit the inflow of relief supplies. Emergency Response Process The federal government, through FEMA, requires all states to have a comprehensive emergency operations plan. These plans guide emergency operations for all types of hazards, from natural to manmade and technological. While the general evacuation issues faced by coastal states are similar, different strategies and plans have been developed to deal with variations in population, geography, and transportation system characteristics. States also differ in the way that they delegate authority, allocate

89 people and resources, and enforce evacuations. A typical goal is to maximize the efficiency of emergency operation plans within these many constraints. Most states take a two-tiered approach to emergency planning and response. For the most part, evacuation planning, response, and recovery activities are developed at the local level. State-level emergency management agencies serve to coordinate cross-jurisdictional emergency management planning and the participation of state-level law enforcement, transportation and other relevant agencies. An example of this approach is illustrated by practices in the State of Texas where potential threats differ widely in the various regions of the state. The Texas State Emergency Management Plan (TDEM 2001) has a general multi-hazard evacuation plan; however, specific hurricane evacuation planning is left up to local coastal jurisdictions. Inland jurisdictions in Texas are concerned more with sheltering and mass care issues rather than the movement of evacuees. In Florida, where the entire state is vulnerable to hurricanes, the state attempts to coordinate the development of evacuation plans. The FEMA/USACE Hurricane Evacuation Study program has also yielded significant benefits in Florida (and other states). It has been suggested that it is the primary reason that most coastal communities now develop hurricane evacuation clearance times and trip assignments. Due in part to the problems encountered during Hurricane Floyd, the North Carolina Department of Transportation (NCDOT) has developed an Emergency Response Procedures Manual (NCDOT 2001). The manual includes plans and procedures for dealing with a variety of emergencies including snowstorms, wildfires, floods tornadoes, and hurricanes. It also includes information on various emergency response and recovery procedures for such issues as debris removal, personnel requirements, and equipment needs. In addition to the planning process, emergency management agencies in the US follow a generally standardized response process. This process is used to declare emergencies then coordinate response and relief resources and efforts. The following summarizes FEMA official response process that first involves preliminary damage assessments which then leads to the declaration of an emergency. It also includes the primary considerations that influence the declaration (FEMA 2008). A governor can declare a state of emergency within his/her jurisdiction and thereby invoke the state's emergency plan to augment municipal and county resources as required. In addition, a governor may also determine that the recovery appears to be beyond the combined resources of both the state and local governments and that federal assistance may be needed. The request for federal assistance must follow the legal process detailed in the Robert T. Stafford Disaster Relief and Emergency Assistance Act, 42 U.S.C. §§ 5121-5206 (Stafford Act) and implementing regulations, 44 CFR Part 206.

90 A preliminary damage assessment involves a review of damage and any emergency costs that have been incurred and the impact to critical facilities like public utilities, hospitals, schools, and fire and police departments. The assessment reviews the affect of the emergency on “individuals and businesses, including the number damaged, the number of people displaced, and the threat to health and safety caused by the storm event.” As part of the assessment process, estimates of the expenses and damages are also made. Ultimately this information is used to show that the costs of response efforts, such as emergency personnel overtime, other emergency services, and damage to citizens, is beyond state and local recovery capabilities exceeding available state and local resources. Based on the results of the assessment, a governor submits a written request to the President through a FEMA regional office. Based on a FEMA review of the request and the findings of the preliminary damage assessment, FEMA recommends a course of action to the President. When developing a recommendation to the President, FEMA guidelines require a number of factors to determine the severity, magnitude, and impact of a disaster event including (FEMA 2008): • Amount and type of damage (number of homes destroyed or with major damage); • Impact on the infrastructure of affected areas or critical facilities; • Imminent threats to public health and safety; • Impacts to essential government services and functions; • Unique capability of federal government; • Dispersion or concentration of damage; • Level of insurance coverage in place for homeowners and public facilities; • Assistance available from other sources (federal, state, local, voluntary organizations); • State and local resource commitments from previous, undeclared events; and • Frequency of disaster events over recent time period. Recently, FEMA has also made it possible for a state to request an emergency declaration in an advance of the impact of a disaster (FEMA 2007). If granted a pre-disaster declaration facilitates pre-positioning of direct federal assistance, equipment, and supplies to meet emergency requirements before a catastrophic hazard, like a hurricane, makes landfall.

91 Authority and Command Structure The emergency response command structure differs in every state. By law, governors in most states have the ultimate authority to order evacuations. However, some governors delegate this authority to local- level officials, such as mayors, city councils, county sheriffs, county judges, or county presidents. This is primarily because these officials have a better knowledge of local characteristics and are better informed on current local conditions. Discussions with emergency management officials suggest this may also be in part because mass evacuations, particularly for hurricanes, can be unpopular and politically sensitive issues since they are so costly and disruptive and (in hindsight) the orders can turn out to be unneeded, too large, or in the worst case, too small. Temporal Processes A critical issue in hurricane evacuations is timing. While some hazards, like hurricanes, typically give many hours if not several days of advanced notice, many give no advanced notice at all. Under these varying conditions, the manner in which evacuations are carried out is equally varied. The earlier the evacuation order is issued, the more time people will have time to evacuate. However, the earlier it is issued the greater the possibility that the hazard conditions could change, rendering parts of the evacuation unnecessary or potentially putting more people at risk during the evacuation. The primary criteria used to make decisions of how soon and how large of an area to evacuate for hurricanes are the storm forecasts and Hurricane Watches and Warnings issued by the National Hurricane Center (NHC). The NHC generally issues advisories on current and predicted storm track, forward speed, and intensity every six hours. As a storm nears landfall or if conditions change significantly from what was forecast, the NHC will issue intermediate advisories every two hours. Although they use the latest storm monitoring and computer modeling techniques to develop their forecasts, the current state-of-the- art is such that these forecasts contain uncertainty in the time frame of one to three days out, when evacuation decisions need to be made. The NHC has made slow but steady improvement in track forecasts over the past few decades, but not as much in intensity forecasts. The NHC average official forecast track errors (for the period of 1989–1998, Atlantic Basin) for 24, 48, and 72 hr were 102, 186, and 278 statute miles, respectively. During the same time period, the average official intensity (wind speed) forecast errors were 12.7, 18.4, and 23.0 miles per hour, respectively. It is apparent that most agencies feel that NHC predictions for hurricanes are not timely or accurate enough since even medium-sized coastal cities need on the order of 12 hr to initiate and

92 complete evacuations before arrival of tropical storm-force winds (39 miles per hour), the most common evacuation termination criteria. The time required to evacuate is estimated from a combination of clearance times and the hazard time. Clearance time for a with-advance-notice hazard typically includes the time required to configure all traffic control elements on the evacuation routes, initiate the evacuation, and any additional time to clear the routes of vehicles once degrading conditions warrant its end. The hazard time for a scenario like a hurricane includes the pre-landfall hazard time during which hazardous conditions can exist prior to the actual hurricane landfall. This occurs as the outer bands of the storm begin to impact the coast, bringing combinations of tropical storm-force winds and potential roadway flooding from torrential rains and storm surge. Clearance times are often estimated using evacuation traffic models, which are themselves dependant on data such as the population anticipated to evacuate, the number of lanes available for evacuation, and other travel impacts that will affect the evacuation, including road closures and blocked lanes. The amount of time required for clearance can also be significantly lengthened by en route congestion and the setup time required for complex control features, such as those required for contraflow. With all of the factors that need to be considered, it is not surprising that pre-planned evacuation times vary widely by location. Many areas will also include additional time for larger hazards that encompass larger evacuation zones in which a greater population is affected. In Louisiana, home to the city of New Orleans, with 1.3 million residents and limited outbound route capacities, an advanced notice of 72 hr before landfall is desired to issue an evacuation order for a hurricane. However, this much advanced notice is difficult given the limitations of current storm track and intensity forecasting. In North Carolina, clearance times for hurricanes can vary from 9 hr in some areas of the state to 24 hr in others. In New Jersey the maximum clearance time is 36 hr for their most southern county, Cape May. In the state of Texas, planned hurricane evacuation clearance times range from 2 to 29 hr. As a safety factor, officials in Texas generally add in 3 hr to advise the public and get the evacuation underway. Thus, depending on the size of the storm and its location along the coast, more densely populated jurisdictions may need as many as 32 hr ahead of storm landfall to make the evacuation decision. Evacuation orders for less populated Texas coastal areas may, however, require much less time. Evacuation Process The most visible part of any evacuation is when people take to the road to flee an impending or existing danger. However, this action is typically only the last step in a process that may have begun hours, days,

93 or even a week prior depending on the type of hazard. The sequence of activities that precedes a hurricane evacuation order, for example, is typically led and coordinated by state-level emergency management officials, incorporating a progression of weather observations, readiness actions, and response activities. The level of urgency at which these activities are undertaken is based on the development and movement of the storm. Thus, while emergency management agencies follow established procedures, the sequence and timing of which may vary widely based on the characteristics of any particular hurricane. In the following sections, the sequence used by the State of Louisiana emergency management officials for a hurricane evacuation is described (Wolshon et al. 2001). This sequence has evolved over time as more experience and knowledge has been gained and is not necessarily representative of every location and for every hazard. However, most states generally follow a similar process in response to hurricane threats. In Louisiana, the Louisiana Governor’s Office of Homeland Security and Emergency Preparedness (GOHSEP) is responsible for developing emergency procedures and coordinating preparedness, response, and recovery functions for hurricanes. GOHSEP uses a four-step “activation” process that transitions their staff from routine operation through the various stages of readiness and response ultimately leading to recovery after the storm (LA OEP 2001). While these procedures are presented relative to the landfall time of an approaching storm, it should be noted that in preparing for hurricane there is no such thing as a “normal” storm. Hurricane behavior is notoriously unpredictable tropical storms can develop into strong hurricanes within hours. Therefore, pre-landfall time references can vary significantly and activations can jump more than one level at a time. Levels V and IV Activation Under routine operation GOHSEP functions at a Level V Activation status. At this level, normal staffing is maintained and no special duties are undertaken. Anytime a tropical weather system forms in the Gulf of Mexico or in the Atlantic Ocean with a track that might take it into the Gulf, GOHSEP moves to Level IV Activation. Level IV represents a very preliminary activation and operations within the management center are still relatively routine. At Level IV, a Crisis Action Team (CAT) is activated to monitor the storm (using National Hurricane Center forecasts) and prepare a situation report for key government officials, including the Governor and FEMA. Communications with local emergency management offices and other involved state agencies such as the Departments of Transportation, Environmental Quality, Health and Hospitals, etc., are also initiated. Based on weather conditions, Level IV Activation could take place up to a week prior to storm landfall.

94 Level III Activation When forecasts show that a hurricane poses a threat to coastal Louisiana, GOHSEP moves to a Level III Activation in which GOHSEP staff moves to an increased state of readiness. At this point a storm strike could be as close as three days away. GOHSEP staff begins to coordinate with the LaDOTD to clear evacuation routes of all obstructions and to collect traffic volume data on key routes on an eight-hour basis. The Louisiana National Guard also determined the need to activate National Guard liaison officers to facilitate the allocation of resources required by local emergency management officials, such as the use of military vehicles for evacuation transportation. The Louisiana State Police may also send liaison officers to the Parishes. At this stage GOHSEP officials also begin to coordinate their activities with bordering states (Texas, Arkansas, and Mississippi), particularly in the area of traffic control measures, as evacuees may need to move across state lines. Level II Activation If a storm continues on a track that threatens the state, Louisiana emergency officials shift to a Level II activation giving them a higher state of readiness. Transition to this level would normally occur two to three days prior to predicted storm landfall. In Level II status, emergency management officials begin to disseminate evacuation and shelter information to the public via various media outlets. GOHSEP also meets with both LaDOTD and State Police officials to determine the status of evacuation routes. At this time the emergency management officials would seek a Declaration of Emergency from the Governor of Louisiana. Level I Activation When a storm strike is imminent, GOHSEP reaches its highest state of readiness. Activities within the Emergency Operations Center (EOC) shift to action-oriented tasks, including making recommendations to evacuate. In Louisiana, evacuation orders can only be issued by local authorities, such as a mayors or parish presidents (the highest county-level officials). Evacuations orders are typically issued at one of two levels “recommended” or “mandatory.” The evacuation order level is critical since it affects several aspects of the evacuation, including the number of people who are likely to evacuate and the implementation of reverse flow operations. The geographic extent and urgency level of an evacuation order are determined after the area at risk has been defined and discussions are held with local-level officials in the risk zones. During a Level I Activation, GOHSEP monitors the status of low-mobility populations such as those from nursing homes, hospitals, and prisons. If problems arise, GOHSEP assists in coordinating resources to transport people out of these facilities.

95 At three hours prior to the onset of tropical storm force winds on the Louisiana coast, GOHSEP issues an order to close all evacuation routes. Evacuation traffic enforcement personnel, members of the news media, and other people who could not or did not evacuate are directed to available shelters. During the storm, GOHSEP remains at Level I Activation and develops post-storm response and recovery strategies. Activities also include assessments of casualties, damage to personal property and critical infrastructure, resource availability, planning for re-entry of the population into evacuated areas, and the coordination of services for the post-storm recovery effort. The process followed by most states includes discussions and consultation with many other state agencies including health and hospitals, commerce, tourism, and natural resources among many others. They also coordinate activities with federal agencies such as FEMA. More recently, states have also begun to coordinate evacuation activities through the FHWA through their developing Evacuation Liaison Team (ELT), which is a cooperative effort between FEMA and FHWA. Evacuation Type Once an evacuation is deemed necessary, the extent and type of evacuation must be determined. The type and urgency is dependent on the characteristics of the hazard and clearance times described earlier. Nationwide, evacuations are most often classified as recommended or mandatory. Recommended evacuations are typically used to warn people in areas in which a threat to life and property exists or will likely exist in the immediate future. Although people who receive such warnings are not required to evacuate, it is to their advantage to do so. In hurricane scenarios, recommended evacuation orders are targeted toward people most vulnerable to hurricane storm surge and extreme winds, including offshore workers, persons on coastal islands, and other special populations having particularly long lead-time requirements. From a traffic perspective, recommended equations are also used as a way to motivate the most threatened people to move first and clear more heavily populated areas before later, more urgent, evacuation orders have the potential to cause congestion and delays along the travel routes. No special traffic control or transportation measures are usually taken during recommended evacuations and people may remain if they so choose. Mandatory evacuations are more serious. During a mandatory evacuation, authorities put maximum emphasis on encouraging evacuation and limiting ingress into threatened areas. These orders are also when most evacuation transportation plans go into effect. Although people are “required” to leave under mandatory evacuation orders, such orders are difficult to enforce and most government agencies lack both

96 the resources and the legal authority to compel threatened individuals to leave. In the past, many people have resisted orders to leave their homes and property by government officials. Under such conditions emergency management officials acknowledge that if a person wants to stay, the state will not physically remove them even if it is absolutely certain that they would be harmed. In discussions with county law enforcement officials in California, it was found that some deputies were able to encourage mandatory evacuations by compelling parents to release minor children to authorities under child endangerment laws. Once children were taken into protective custody, parents would make decisions to leave as well. Other, more ambiguous, evacuation terminology was also found across the country. Words like voluntary and precautionary are also used in some locations. It was also learned that the terms “recommended” and “precautionary” are often used interchangeably and are not necessarily as clearly defined as the previous two. One agency described their precautionary evacuations as “pre-voluntary” and thought of them as a way to get people or entities in need of long preparation times or those in recognized at-risk areas to move toward action. Again, decisions of whether or not to leave are left to individuals and few special transportation arrangements are made. The definition and terminology of evacuation declarations are important because they impact peoples’ decision of whether or not to leave. Prior research has shown that people who said they heard mandatory evacuation orders are the most likely to evacuate; while recommended evacuation orders are met with less urgency (PBS&J 2000). The type of evacuation order and how it is communicated is also critical to avoid spontaneous evacuation, also referred to as shadow evacuations. Shadow evacuations occur when people who believe they are at risk evacuate even though they have not been officially advised or recommended to do so (Gunter 2001). Shadow evacuees most often leave because of concern about safety but could also leave for other reasons. Authorities in Florida and Texas feel that the one of the reasons for the extreme number of evacuees during Hurricane Floyd then later in Rita was the result of shadow evacuations. However, it has been suggested that the over evacuation problem in Houston also resulted from vague and inconsistent instructions provided by the authorities.

Next: Appendix C Survey Questionnaire »
Transportation's Role in Emergency Evacuation and Reentry Get This Book
×
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 392: Transportation's Role in Emergency Evacuation and Reentry explores information on transportation's role in emergency evacuation and reentry by summarizing aspects of its planning, control, and research as well as highlighting effective and innovative practices.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!