Office of Operations
21st Century Operations Using 21st Century Technologies


1.3 General Timeline of Events

For the purpose of this study, a no-notice disaster that results in an emergency evacuation can be divided into phases, based on a timeline of events, as shown in Figure 1. The six phases of activities that form a general progression of events are:

  • Phase 1 – Advanced Planning

  • Phase 2 – Incident Notification

  • Phase 3 – Activation and Mobilization

  • Phase 4 – Evacuation Operations

  • Phase 5 – Re-Entry

  • Phase 6 – Debrief and Assessment.

Figure 1: Phases of a No-Notice Emergency Evacuation

Diagram of the six phases in a cycle. More details are below.

Given the spontaneous and chaotic nature of no-notice emergency incidents, these phases are likely to overlap in time. Therefore, the progression of these phases is not meant to indicate a firm timeline.

Advanced Planning – Ideally, some level of planning and organization will have been established prior to an event actually taking place. The planning phase would assume that agencies have worked together to establish a cooperative system for just such an emergency including roles and responsibilities, resource management and infrastructure operations, and key points of contact for agencies that would be involved. Education of the public would also be covered as advanced planning.

Incident Notification – This phase assumes an incident has occurred and been detected, and notification must be established. This is when the incident command system (ICS) is initialized.

Activation and Mobilization – This phase involves the dissemination of information to the public and all preparation for the actual evacuation. The ICS will be established and operational.

Evacuation Operations – This phase covers the actual exit movement and transfer of people and goods from the affected area to another. State, county, and local agency support will be directed through the ICS.

Re-Entry – This phase involves the ingress of evacuees. It will require coordination among local, county, and state agencies, through the ICS, to ensure a safe and orderly re-entry process.

Debrief and Assessment – The final phase in the evacuation process occurs after a majority of the evacuees has returned, the ICS is disassembled, and day-to-day operations are more or less “back to normal.” This phase addresses the need for all agencies involved in the evacuation process to sit down together and evaluate the overall evacuation operation from beginning to end.


June 26, 2006
Publication #FHWA-HOP-08-020