Using Highways During Evacuation Operations for Events with Advance Notice

Routes to Effective Evacuation Planning Primer Series

Produced in collaboration with the Intelligent Transportation Systems Joint Program Office (ITS JPO)

Operations: Readiness Phase

During the readiness phase, information becomes available that an incident has occurred or is anticipated that may require an evacuation. That information must be relayed as quickly as possible to the decision makers so that they can determine whether an evacuation should be ordered.
Stakeholders critically involved in the readiness phase may be viewed as:

Decision Makers—Usually only one political authority with the power to make the ultimate decision to evacuate one or more areas

Decision Influencers—Factions with a political, social, or economic stake in decisions to evacuate

Information Providers—Those that have information that may ultimately be used to make a decision whether to evacuate.

It is important that these partners are identified and know their roles—and limitations—in the evacuation decision-making process.

As the event moves from theoretical planning and preparedness to this first operational phase, authorities rely on information—fast, reliable, and in usable form—for making decisions and designing operational and tactical response plans specific to the event. Information plays an especially critical role in evacuation readiness efforts. Transportation officials act as information providers to the decision makers. Information should be collected from official sources to ensure reliability. It should be readily available, interpreted, and continually collected during all phases of the evacuation operation. All event-specific plans should be updated as new information becomes available. The agencies listed in the box may be tapped for demographic data; meteorological data; geographic data; and transportation, transit, and traffic data, all of which can support the development of a good evacuation plan and evacuation decision-making. Modeling tools—including decision support tools—may be used to obtain information that can assist planners in providing the impact areas of some events such as hurricanes or airborne hazardous materials releases. Some of these tools are described in the “Evacuation, Weather, and Assessment Monitoring and Prediction Tools” section of this primer.

Reliable baseline data should have been collected and continually updated as a part of a jurisdiction’s preparedness efforts. At this point in the operation, baseline data is essential to a good evacuation strategy. For example, decision makers and evacuation operations personnel need to know how many people must be evacuated from a specific geographic area and the highway routes available for their evacuation in order to calculate the time needed to execute an evacuation. Planners should consider that some people will decide to evacuate their families using multiple vehicles to prevent damage to vehicles if left at home. This behavior was observed during the evacuation for Hurricane Rita in 2005, and the additional vehicles contributed to the roadway congestion. Therefore, planners should consider not only the number of people to be evacuated, but also the number of vehicles.

Since many disaster-vulnerable areas are also tourist locations, elements of non-resident populations need to be factored into evacuation plans during the readiness phase. Public school management should also be involved so that if a disaster strikes when schools are open, the plan includes ensuring the safety of students as well as the school’s role as local shelter, feeding site, and supplier of school buses for evacuation.

As emergency managers monitor emerging situations, certain points may be reached that should trigger the movement of decision makers and emergency team members to the EOC to facilitate coordination, information management, and decision making. At this juncture, the decision makers should receive information, options, and recommendations based on the best-available information, and emergency managers should develop an evacuation tactical plan. In developing this evacuation strategy, organizations may use a step process and a “countdown” timeline to decide if and when they will evacuate an area based on collected information and what steps should be taken at critical times. This process also may be used for the recovery period after an event has occurred. At each key timeline point, the evacuation plan should address steps to take and agency assignments by task.

Many factors affect a decision to evacuate an area. Foremost is the potential danger to lives and property. Officials need to know about the severity of the potential danger so they can make informed decisions about whether or not to evacuate an area. Of course, the officials must have the legal authority to order and enforce an evacuation. While, ultimately, a single official is responsible for and has the authority to order an evacuation, that person seeks information and recommendations from many sources depending on the nature of the event causing the potential evacuation. Emergency planners, first responders, transportation technical professionals, and others contribute information and recommendations about their readiness to support an evacuation. Among the recommendations provided to decision makers should be the type of evacuation the situations warrants. Evacuations are classified as one of three types:

Voluntary—Targeted toward people most vulnerable to the threat including offshore workers, persons on coastal or barrier islands and other flood-prone areas, and other special populations having particularly long lead-time evacuation requirements. This also includes people in harm’s way from other events. No special traffic control or transportation measures are usually taken during voluntary evacuations, and people may remain if they so choose.

Recommended evacuations—Issued when an event has a high probability of causing a threat to people located in at-risk areas. Again, decisions of whether or not to leave are left to individuals, and some special transportation arrangements are made.

Mandatory evacuations—Issued when authorities put maximum emphasis on encouraging evacuation and limiting ingress to potentially impacted areas. This type also occurs when evacuation transportation plans go into effect. Mandatory evacuations are difficult to enforce as many people resist being ordered by government officials to leave their homes and property.

Ordering an evacuation is one of the hardest decisions that anyone can make. The decision could put people in harm’s way from other events, cause emotional and physical distress to those at risk, cost the community considerable money, and open the evacuees to looters and other security issues. As a result, decision makers, decision influencers, and information providers collectively must deem the decision to evacuate outweighs other risks. To weigh this balance, the decision process should address the following items, at a minimum, to determine whether to evacuate, what areas to evacuate, when to evacuate, conditions of evacuation, resources needed to evacuate people, and how to evacuate.

  Probability of impact (depending on nature of event) National Weather Service (NWS), DHS, local fire officials, etc. depending on nature of event
  Estimated effects—geographic area to be evacuated Impact models
  Timing of event EOC
  Lead time for an evacuation Evacuation models and DOTs
  Timing of notifications/orders EOC
  Weather conditions NWS
  Economic impacts to government and private sector Impact models and Chamber of Commerce
  Condition and availability of evacuation routes DOTs
  Evacuation decision by neighboring jurisdiction EOC
  Number of tourists to evacuate Convention/Visitors Bureau
  Number of transit dependent to evacuate Transit Agency and Human Service Agencies
  Number and type of people with special needs to evacuate Transit Agency and Human Service Agencies
  Populations potentially impacted Impact models
  Availability and safety of personnel to support an evacuation Human Resource Departments
  Vulnerable transportation infrastructure or potential transportation targets identified DOTs
  Selection of staging areas that may include transportation facilities DOTs
  Ability to stage transportation assets for movement of those who cannot self-evacuate DOTs, Transit Agencies and Human Service Agencies
  Ability to coordinate traffic control devices DOTs
  Plan for shut down of highway work zones, non-essential commercial vehicle traffic including oversize loads, hazardous materials, etc. DOTs
  Process to suspend toll collections on public and private toll roads DOTs and Toll Road Operators
  Ability of TMCs/TOCs to move into evacuation readiness status DOTs
  Ability to implement contraflow if required DOTs and Highway Patrol
  How to evacuate while enabling incoming response personnel, equipment, and supplies DOTs and Highway Patrol
  Transportation resources available to conduct evacuation and move evacuees, including availability of assets through State (e.g., National Guard), mutual-aid, or regional agreements DOTs, Highway Patrol, and EOC
  Number of first responders in impact zone and whether they can move their families out of affected areas before reporting for duty Human Resource Departments
  Location of shelters/reception sites EOC
  Ability of planned shelters/reception sites to receive evacuees EOC
  Potential for reimbursement of evacuation costs State EMA and FEMA