INFORMATION SHARING FOR TRAFFIC INCIDENT MANAGEMENT
The Incident Timeline 16
While nomenclature and details can vary from state to state, there are generally five areas recognized as part of the incident timeline. Each step has unique characteristics that allow for performance assessment in after-action reviews. When changes to administrative, operational, or technological processes are implemented, the overall duration of an incident and its impacts can be shortened. Key elements to shorten timeframes are: implementation of intelligent transportation systems (ITS), inter-agency coordination, and improvements derived from after-action reviews.
Incident Detection
The crash or incident occurs, and traffic queues begin to build from lane blockages or “rubbernecking.” The earlier responding agencies are aware of an incident, the more quickly resources can be sent to resolve the situation. Automating this process through the use of detection equipment removes the reliance of human detection, whether by law enforcement/emergency personnel notification or cell phone calls from passing motorists. This is the first time someone in an official capacity learns of the incident and has an opportunity to follow a response plan.
Incident Verification
Once an incident is detected and a response agency (transportation management center [TMC] or law enforcement) is aware of an incident, the location, scope, and impact of the event must be verified quickly so that the appropriate resources can be sent out to the scene. Verification through closed-circuit television (CCTV) cameras or video from other sources is extremely useful because it eliminates the time needed to send a person to the scene for verification. Scene images can often be shared with multiple responding partners so that all can take appropriate action.
Incident Response
Incident response resources are called for and then arrive. They can include law enforcement, transportation agency resources, wreckers, hazardous material clean-up specialists, specialty equipment, etc. Having the personnel with appropriate resources and training arrive quickly is critical. Pre-established routes or wrong-way access to a site while following a law enforcement pilot vehicle are examples of ways response vehicles may avoid traffic queues that grow quickly after an incident occurs.
Incident Clearance
Once the area is declared safe for cleanup for responders, motorists, and other personnel on scene (there may be fire or other dangers, loads may be unsafe, etc. that must be addressed first), the incident response team can get to work. The response team must have the right equipment available so that scene clearance and temporary repair work, if needed, can begin so that the roadway can be re-opened to traffic. This time is lengthened if equipment is missing; the full complement of needed equipment must be at the incident scene. Changes to the clearance component of the incident timeline may be addressed during multi-agency sessions (traffic incident management team meetings and workshops) where traffic incident management (TIM) partners discuss and learn from previous and proposed practices. Development of agreements, execution of tabletop exercises, and discussion of after-action reviews are also extremely helpful in reducing incident clearance times. Sharing automated information, clear communication, understanding and agreeing upon roles and authority, and cooperative work efforts go a long way in addressing incident scene needs by minimizing institutional barriers and increasing collaboration. These areas are best addressed away from the incident scene so that interactions between responders are clear and all roles are understood rather than when actions are critical and pressure mounts for the roadway to re-open quickly.
Incident Recovery
When the incident is finally cleared and the roadway is re-opened, time is needed for queues to dissipate. Recovery time is the period from the re-opening of all lanes to the resumption of normal traffic flow. This time is largely dependent upon the length of the queue from the incident; an accepted estimate is that for every minute of lane closure, four minutes of recovery time is needed once lanes are re-opened. If fewer vehicles join the waiting traffic stream and possibly divert to other roadways or modes, they do not become part of the incident queue, in turn shortening the time needed to resume normal conditions. Traveler information services, partnerships with the media, and ITS information dissemination devices placed in advance of the queue help travelers make route decisions that can keep them from driving unwittingly into an incident queue for an unknown period of time. Because travelers themselves have a part in controlling this part of the incident timeline, the information they receive must be accurate, timely, and reliable.
