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 Photograph of the light component on top of a police patrol car.

Little- or no-notice incidents and resulting evacuations produce a distinct set of challenges for those personnel involved in responding to the incidents or executing the evacuations. Transportation professionals, emergency managers, first responders, and local governmental decision makers must address these challenges in advance of needing to implement an evacuation. The focus of this section is to provide an understanding of the unique issues associated with no-notice incidents. Section 5 addresses the planning considerations that can be used by evacuation personnel to alleviate these challenges.


The most significant challenge posed by no-notice evacuations is that they do not provide emergency managers and transportation personnel with the opportunity to prepare in immediate advance of the incident. The limited amount of time between when the precipitating incident occurs and when a no-notice evacuation is initiated means that there will be little or no Readiness Phase. The lack of a Readiness Phase means that responders will be forced to rely on their existing capabilities, experience, and level of preparation.

Responders will be unable to pre-activate or pre-position resources in preparation for the specific situation mandating the evacuation. Government officials must weigh the costs and benefits of evacuating populations based on very limited information (damage and predictions for imminent secondary events, such as after-shocks). Preplanning activities, conducted as part of general operations well in advance of the need for an evacuation, are critical to a successful evacuation effort and are among the most important factors in minimizing the effects of no-notice incidents. These activities include planning, procurement, staff training, and public education efforts.

Due to the limited or non-existent Readiness Phase in a no-notice scenario, evacuation plans and any supporting protocols that require a significant "ramp-up" period will be rendered unusable or, at a minimum, greatly reduced in effectiveness. This applies to such elements as the establishment of a command structure, the activation of an operations center, or the tasking and distribution of personnel and resources to manage the evacuation.3 Key decision makers will have little time to assess the available information and make a decision about how to respond to the situation. They may be required to decide whether to declare an evacuation before they have all the necessary information to do so as planned.

Photo. A manned rescue boat searching a town during a major flood.
Source: FEMA/Jocelyn Augustino.

Also, emergency responders will have no or limited time to familiarize themselves with the evacuation plan and consider its implementation after a no-notice incident. If critical staff have insufficient training and have not participated in exercises involving the plan, the plan's effectiveness will be greatly reduced. To increase the plan's effectiveness, it is essential that transportation operations personnel be included in exercises and training with other first responders.


After a no-notice incident, emergency managers will most likely work with limited information to assess the situation. There will be no time for a thorough assessment to take place before decision makers have to decide if and how they will implement an evacuation.

Emergency management and transportation officials will need to be prepared to act with imperfect situational awareness. This implies that they may not know the status of all components of the transportation network, including whether any critical sections are inoperable. Officials may also not have a full and accurate inventory of the personnel and resources available to support the evacuation effort. Decisions will most likely rely heavily on the estimates determined during preplanning, using the limited real-time information received as a guide. While the situational awareness deficiency may improve over time, officials will be forced to make the best decisions they can based on whatever information is available to them at the time.

This issue highlights the importance of two aspects of information management. First, information that is prepared and analyzed in advance becomes critical in a no-notice scenario; data such as population estimates (daytime and nighttime), locations of those with special needs, demographics on the number and location of individuals depending on transit, vulnerabilities in the transportation network, and resource inventories all help to improve the decision-making process during the evacuation. Second, effective and resilient information and communications systems and protocols will greatly improve the availability of accurate real-time information after a no-notice incident. Agencies' abilities to improve overall situational awareness by collecting and sharing information quickly will enable better decisions.

Photo. An incident management meeting.
Source: FEMA/Jocelyn Augustino.

Once a no-notice incident occurs, damage assessments will contribute to a more accurate operational picture, and tactical operations will have to be highly flexible in order to adjust. ITS tools used on a day-to-day basis may also be extremely useful for obtaining a rapid assessment of the transportation infrastructure after an incident. TMC staff should be tapped by the EOC to interpret and report on visuals from traffic cameras that are still operational throughout the area. These cameras, augmented with security cameras and immediate windshield surveys by first responders and full-function service patrols on the ground, are often overlooked resources, but may be critical to obtaining a rapid snapshot of ground conditions and infrastructure damage that will cause operations, including evacuation efforts, to change.


In the immediate aftermath of a little- or no-notice incident, responders likely will need to conduct an evacuation under less than ideal circumstances due to the time criticality inherent to life saving/sustaining situations. This means that although officials will conduct the evacuation to the best of their abilities, it may still fall short of their expectations because of the challenges posed by no-notice evacuations. Flexibility, good information sharing, and quick decision making will be required to adapt to limitations imposed by the incident, and compromises will need to be made to support some of the evacuation's primary goals – particularly evacuating the at-risk population away from imminent danger.

Emergency managers, first responders, and transportation officials must be willing to use imperfect, short-term measures in the interest of timeliness. They may employ tactics that address an immediate need: the safety of evacuees may have to become the priority over their comfort, with the primary concern being the movement of evacuees from imminent danger. For example, evacuees in cars may need to be directed onto highways and other routes that will enable them to travel out of the at-risk area but then require them to spend a significant amount of time in gridlock, instead of being able to continue on to their destinations right away. While this may not be an ideal solution, it accomplishes an evacuation's main goal of moving citizens out of an at-risk area.

Photo. A police officer speaking into a portable two-way communication device.

In mounting a response that returns the transportation systems back to operational status as soon as possible, transportation agencies will need to have contracts in place with contractors and vendors that allow them to secure needed resources. Otherwise, there needs to be a willingness to enter "handshake" agreements that will result in actions to restore mobility and repair infrastructure damaged infrastructure as soon as possible.

Depending on the magnitude of the no-notice incident, evacuees may need to spend time at an interim destination in a safe location outside the at-risk area if long-term sheltering is not yet available. Interim sheltering sites may have insufficient food, water, and supplies to be much more than stations where people must spend a few hours before relocating to adequately equipped sheltering locations.

Emergency managers, first responders, and transportation officials will need to accept and implement a steeper triage curve in the assistance they provide to evacuees. Normal response agencies (fire, police, and emergency medical services) will likely need to respond to the precipitating incident and its aftermath, and may not be available to help support the evacuation effort. Limited response resources will have to be tasked in a manner that is most effective for those who require additional or specialized assistance. Some evacuee populations – such as healthy people who do not have access to a personal vehicle – who might have timely access to transportation services under an advance-notice scenario may need to be more self-reliant or endure a longer wait for transportation during a no-notice evacuation in which fewer vehicles are available to offer transport.


As part of the evacuation planning process, transportation officials – in consultation with emergency managers and first responders – will identify traffic management tactics for use during an evacuation to improve traffic flow and minimize congestion. These may involve a wide range of methods, particularly adjusting the timing of traffic signals, closing highway on-ramps and off-ramps in key locations, and instituting contra flow on some roadways. All of these tactics, however, require time, effort, and, in many cases, specialized systems and resources to implement, and may not be available to support an evacuation immediately following a no-notice incident. Some strategies, such as contra flow, require three to five hours to set up, and may not be a viable option. Many jurisdictions view extreme tactics, such as contra flow, as a last resort for this specific reason. Evacuation plans need to anticipate the unavailability of certain tactics in a no-notice scenario. Requirements for implementing traffic management strategies need to be well understood and actions to minimize these issues should be considered.

Photo. A shelter house with cots providing refuge for evacuees.
Source: FEMA/Dave Gatley.

Because some traffic management tactics may take too much time to implement in the immediate aftermath of a no-notice incident, other tactics will have to be utilized until the traffic management tactics are brought up and running. This limitation will vary greatly, depending on the specific tactics being considered and the circumstances of the incident that precipitates the evacuation.

For all intents and purposes, traffic management tactics that require substantial time or empty roads to implement are much less feasible options for no-notice evacuations. Because severe time constraints are inherent in a no-notice scenario, emergency managers and transportation officials cannot employ the tactics before evacuation traffic starts to load the transportation network.

There are also instances where the actions of evacuees might interfere with transportation's response. In some cases, individuals may initiate their own uncoordinated exodus before an evacuation is declared. This could be especially troublesome when a phased evacuation is identified as the best course of action. If evacuees flood the roadways and evacuation routes in a chaotic manner, this may lead to a further burden on an already overtaxed transportation system.


Decision makers must recognize that there are situations in which the timeframes dictated by a no-notice incident do not allow for evacuations, or that evacuations may put the affected population at greater risk. They must weigh the dangers of telling populations to shelter in place against the known or unknown risks of moving in the immediate aftermath of an incident. The nature and scope of the precipitating incident may generate hazards that pose a serious threat to the at-risk population if an evacuation occurred. Examples of such risks are compromised transportation infrastructure, impacts of aftershocks, the presence of toxic or radiological contaminants (particularly a plume), impending weather conditions, and secondary fires and explosions. In such situations, having at-risk populations shelter in place with basic protective measures may be a more viable and safer option.

The use of sheltering-in-place to reduce the number of people who become part of an evacuation stream or who need to be moved by public transportation is an option that emergency managers can consider, but only if the present location affords adequate protection against the particular incident. This decision may have unintended consequences and risks for those ordered to remain inside and for the decision makers. For example, a Louisiana nursing home staff's decision to shelter in place during Hurricane Katrina resulted in considerable loss of life among the residents when water filled the structure, and manslaughter charges were brought against the facility's owners.4 The incident's influence on basic human necessities - such as potable water - must be considered when deciding whether citizens should evacuate or shelter in place.

The proportion of the at-risk population that will stay or evacuate is not easily predicted. Activities related to implementing an evacuation may need to be performed, even if sheltering in place is recommended or ordered, since spontaneous evacuations and changes in the threat situation may require reassessment of the protective action strategy. At-risk populations may also decide to disregard instructions to shelter in place, based on a mistaken belief that it is safer to evacuate.

Shelter-in-place activities can be short-term or long-term, depending on the particular circumstances of the incident, the degree of safety risks to the population associated with the incident, the resulting traffic congestions, and the resources available to support the shelter-in-place population. Those services that would be provided at a shelter should also be supplied to those sheltering in place. As such, service providers, including health care workers, feeding staff, etc., must be able to travel around the affected area safely.


Photo. Hazard response team dressed in full personal protective equipment, inspecting a potential source of contaminants.
Source: FEMA/Win Henderson.

Some incidents that lead to evacuation generate associated hazards that can contaminate people, vehicles, and structures. The nature of the contaminants will vary with the nature of the incident and its cause, and different contaminants may require different approaches to exposure, decontamination, and treatment. Of particular concern to emergency response personnel are terrorist attacks that involve chemical, biological, radiological, nuclear, or explosive (CBRNE) devices. Some of these attacks are designed to cause immediate casualties and damage as well as to disperse harmful substances that will continue to harm victims and prevent the use of the affected zone.

The presence of contaminants in an at-risk area will greatly complicate the execution of an evacuation. Evacuees will be limited in their ability to move through the affected area safely. Responders may not be able to enter the area without subjecting themselves to an unreasonable level of risk, or may need to wear and use specialized personal protective equipment to protect themselves. Potential evacuees may have no means of leaving their locations without becoming contaminated. In such scenarios, sheltering in place must be considered as a potential short-term strategy for minimizing casualties if the situation and available resources are appropriate.

Evacuees who may have been exposed to harmful substances will need to be quarantined to prevent the spread of contamination to unaffected locations and populations. Decontamination of evacuees, requiring specialized screening and cleaning resources and expertise, may be necessary before evacuees are transported to advanced care and sheltering facilities. The more the population is dispersed throughout a contaminated area, the more complex the decontamination operation and medical treatment and tracking systems will be when people are able to leave.

Photo. A water-delivery service preparing resources for disaster response.
Source: FEMA/Bob McMillan.

Evacuation managers also need to anticipate that some evacuees will disregard orders to shelter in place and will self-evacuate before the nature of the contaminant is known. Procedures will be needed to notify potentially contaminated evacuees, identify and locate them to the greatest extent possible, and quarantine them as soon as possible before they contaminate others.


Large-scale incidents may have significant impacts on critical infrastructure elements, rendering them damaged or otherwise unusable. Disaster scenarios such as severe earthquakes and major explosions involve large areas of destruction that may encompass the systems and resources needed to execute an evacuation. Vulnerable infrastructure often includes components of both the transportation network as well as assets that will be used to coordinate and manage the evacuation effort.

Certain precipitating incidents will likely cause significant damage to parts of the transportation network. Structures such as bridges and tunnels which are particularly susceptible, are at the same time critical links in a jurisdiction's network. The damage or destruction of these types of sites may prevent the use of certain evacuation routes until they can be repaired. Even if these sites are undamaged, they should not be used until their structural integrity has been verified through inspections conducted by qualified personnel. Transportation planners and emergency managers should be prepared to close hazardous or questionable routes, and will need to anticipate what routes are likely to be unavailable. While DOTs have in-house structural engineers that can validate the integrity of roads, bridges, or public transit networks, a significant amount of time may be required before such inspections can be completed and the routes can be approved for use because of the limited resources and staff available immediately following a no-notice incident.5

Photo. Birds-eye view of interstate.
Source: FEMA News Photo.
Photo. End of a road approaching a destroyed bridge.
Source: FEMA/Mark Wolfe.

Critical emergency management and transportation operations assets, including ITS cameras, DMSs, etc., may also be damaged or destroyed during a large no-notice incident. This will greatly limit the capabilities of emergency responders to collect damage assessment and situational awareness information, to target and coordinate their response efforts, and to manage the evacuation. Planned sheltering sites and building may be destroyed or contaminated. Facilities such as EOCs and TMCs are vulnerable to the same threats as any other buildings and can be destroyed or rendered inoperable by loss of power or of the communications capabilities necessary for them to function as designed. The power grids, as well as many communications systems, rely on extensive networks of equipment, wiring, relay stations, and other resources. As past incidents have demonstrated, the loss of even minor nodes or equipment can disable an entire network. For this reason, many of these facilities and systems are designed to be more resilient through the use of redundant components; nonetheless, their loss can still occur. In addition, any continuity of operations plans must be coordinated with transportation agencies in consideration of the continuity of the transportation operations and infrastructure efforts, in case they are moved to alternate sites. More and more, many communities plan to use their TMCs as alternate EOCs, often because they are located outside of areas that are most likely to be impacted by an event, such as a terrorist attack or hazardous materials spill.

Transportation and emergency managers will need to assess the infrastructure and systems on which they rely to identify and address critical vulnerabilities. Contingency plans should anticipate weak points in the transportation network and response infrastructure and include provisions for their possible loss.


The effective execution of an evacuation and sheltering effort requires a significant amount of diverse resources. Different assets and tools are needed at different stages of the operational phases, each with its particular role in the overall process. Examples of key resources include:

An absence or shortage of these types of resources can significantly hinder certain phases of operations during an evacuation.

No-notice incidents and the need for immediate response activity, including evacuation, leave little time to procure and position needed support resources after the precipitating incident occurs. For the early phases of response, if not for significantly longer periods of time, emergency managers and transportation officials will have to rely on the assets and resources at hand, namely those that are used in their daily operations or are pre-positioned on a more or less permanent basis. Since many assets, such as vehicles and specialized equipment, are often stored in remote locations or assigned elsewhere during normal operations, they may not be available right after an incident occurs. The limited immediate availability of personnel and equipment to support the evacuation effort emphasizes the importance of identifying needed resources in advance and planning for their availability through procurement and logical pre-positioning.

The emergency management structure will likely face the same types of challenges for staffing. Many personnel may be off-duty and located outside the area at the time the precipitating incident occurs. These people may be unable to report to their duty assignments for a variety of reasons: they may be prevented from traveling into the affected area to reach the management facilities due to travel restrictions imposed as part of the emergency response; they may have been injured in the precipitating incident; or they may be trying to meet their personal needs by protecting their own families and property. These limitations will apply to all levels of personnel, from field workers up to command-level staff persons.

Planners and response personnel need to anticipate that their resources will likely be limited to "everyday" staffing and supply levels. As a consequence, plans must be structured in a way that minimizes the reliance on particular individuals, facilities, and specialized equipment.




Construction Equipment


Tow Trucks


Traffic Control Devices



Evacuees and responders will likely behave differently in a no-notice incident scenario than they would after an incident with advance notice. Anxiety and confusion will be generated by the uncertainty of the situation, the sense of acute risk, and the need to react quickly to developing incidents. Planners need to anticipate that responders' and evacuees' behaviors will impede the smooth execution of the evacuation plan.

Some portion of the population will likely undertake a self-initiated evacuation before receiving an evacuation order if they believe they are or will be at risk. This means that many people who are not at risk may evacuate even though they do not need to, potentially placing themselves at risk and increasing the size of the evacuation population, thus contributing to overall congestion in the transportation network.

There will also be self-motivated actions that conflict with the evacuation plan. Some percentage of the at-risk population will likely attempt to travel in a direction or manner that does not conform to the evacuation plan's intended traffic flows: parents will attempt to retrieve their children from schools or home-bound relatives in other parts of the affected area; people will generally try to head to their homes or those of friends, even if they are in the "wrong" direction; and people may try to use modes of transportation that are intended to be limited to certain routes or locations. This will generate some level of traffic that crosses or conflicts with evacuation routes.

There may be a refusal to follow a 'phased evacuation,' in which smaller zones of the at-risk region are evacuated sequentially to minimize traffic congestion. Many people, due to an acute sense of personal risk, may not wait for their turn to evacuate even if it would be safer or more effective for them to do so.

In addition to self-evacuations, there are some portions of the at-risk population who may refuse to evacuate at all, even after being ordered to do so.6 A 2007 study, conducted by the Harvard University School of Public Health among residents in high-risk hurricane areas, found that 31% of people surveyed may not evacuate even when told to do so. The reasons for not doing so were varied: belief that they would be safe at home; desire to protect their property; uncertainty that they will be able to travel safely; or a lack of confidence that they will be able to be sheltered elsewhere. Some portion of the at-risk population may procrastinate until it is unsafe to evacuate. People may judge the threat to be less severe than it is, or may be worried that evacuating poses more of a risk or inconvenience to them than staying in place. As the situation escalates, however, they may decide later to evacuate, even though it has become much more dangerous to do so. Their delayed attempts at evacuation may also place the first responders who assist them in greater danger as well by prolonging their time in the at-risk area. Plans for evacuations that are deemed mandatory by officials will need to incorporate a means of sweeping the affected area and of enforcing the evacuation order.

First responders and emergency personnel might also be affected behaviorally by a no-notice incident. Responders' private considerations may interfere with the performance of their duties. They may live in the affected area and have family members, friends, and property they feel compelled to assist and protect. Their sense of personal duty and concerns about personal matters may interfere with their ability to carry out their professional responsibilities as part of the overall evacuation effort.

There are many unique issues associated with no-notice incidents. These challenges must be considered before an incident occurs in order to enable a response in the most effective manner. Section 5 provides planning suggestions that can be used by evacuation personnel and transportation officials to alleviate the unique challenges posed by a no-notice incident and its resulting evacuation.

3 Since 9/11, many local, State, and Federal governmental entities maintain a base 24-7 operation in their EOCs to ensure rapid command, control, and operations following quick-onset events, including terrorist events.
4 "Katrina Nursing Home Owners Acquitted in Patients' Deaths."
5 Caltrans' response following the Northridge earthquake provides a best-practice model of an agency's quick response following a no-notice event, in terms of rebuilding the impacted highway infrastructure and providing mobility. On the same day that the event occurred, Caltrans demonstrated flexibility in its response and set a number of actions in place to begin repairing highway and bridge damage. Knowing that obstructions and debris must be cleared, damaged facilities shored, and detours established, Caltrans made "handshake" agreements with contractors on work assignments and tentative payment methods. By 7:00 p.m. the first night, the first contracts were in place and work had already begun on I-5 and I-10 demolition.
6 For study overview information and links to data, see

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