Using Highways During Evacuation Operations for Events with Advance Notice: Routes to Effective Evacuation Planning Primer Series
Transportation networks provide a key service during emergency evacuations. Transportation operations significantly determine the safety and efficiency with which evacuations are implemented. Although there may be multiple modes of travel involved in evacuating populations, the most frequently and heavily used are highways and secondary roads. A basic approach to strengthening the service of the transportation network in emergency evacuations is to involve the transportation community in the planning process. Fully linking the transportation sector with emergency management in all phases of preparedness will enhance the ability of the transportation sector to support emergency evacuations. Thus, the state and local agencies responsible for emergency evacuations have an interest involving the transportation sector in the development of emergency plans as well as their implementation.
The Federal Highway Administration (FHWA) has produced a primer for emergency response managers and transportation officials entitled "Using Highways during Evacuation Operations for Events with Advance Notice." The primer serves as a guide for local and state planners on the lessons learned and best practices for maximizing the use of the highway network in emergency evacuations. A fundamental step recommended by the FHWA primer is to involve transportation subject matter experts and those with appropriate authorities in the evacuation planning process. In addition to lessons learned, the FHWA primer discusses transportation resources including ITS tools, traffic operations and incident management that can support emergency evacuations.
There are a multitude of transportation tools that can support evacuation operations in emergencies with advance notice. As the agency responsible for emergency management develops emergency response plans, it is useful to review the array of transportation tools available for support in emergencies. For example, transportation tools for communicating with the public can support emergency management’s effort in communicating evacuation orders to the public. Similarly, tools that help manage traffic operations can be used in emergency operations for the purpose of increasing traffic capacity on evacuation routes and responding to traffic incidents that can harm the evacuation effort by blocking traffic. As the evacuation is ongoing, emergency management can use monitoring/predicting tools for monitoring conditions and predicting outcomes. These tools can improve the response team’s situational awareness of the progress of the evacuation, help identify potential problem areas and determine optimal evacuation routes. The transportation tools listed below identified by the FHWA as having potential to support emergency evacuations with advance notices.
Communication Tools. A critical element in emergency evacuations is the ability of emergency response officials to communicate to all segments of the population in the evacuation zone. The following communication tools can help emergency management communicate to the public:
- Traveler Information-Dial 511 is the single traffic information telephone number in use by states and local jurisdictions (since 2000). As of 2008, nearly half of the states and metropolitan areas have 511 services. Nationwide availability of 511 is expected by 2010. The service is provided free of charge or the cost of a local telephone call. In addition to telephone information, many states provide comprehensive traveler information on 511 information websites. Evacuees with mobile or landline telephones (or an internet connection) can dial 511 to access current information for specific routes and roadway segments, including anticipated travel delays, traffic accidents, roadway blockages and lane closures. Roadside sensors that monitor traffic along highways permit the calculation of travel times.
- Loud Speakers that are located in the community can be used to alert people within a specific location, and loud speakers mounted on vehicles (e.g., roving police cars) can broadcast emergency information across different neighborhoods.
- Siren Systems are used to alert people when immediate action or cover is required (e.g., tornadoes or tsunamis).
- Handouts providing evacuation information (such as emergency preparedness steps, evacuation routes and locations for shelter and food) can be distributed at highway rest areas, transit stops, turnpike service plazas, gas stations, hotels, etc.
- REVERSE 911 enables emergency management to place thousands of phone calls simultaneously to residents to provide evacuation information. The service also enables communication with the hearing impaired with an optional Telephone Device for the Deaf.
- Variable Message Signs (VMS) are either pre-installed or portable, and they can be used to display information to direct motorists to the evacuation route and to shelters.
- Commercial and Public Media are a critical resource for emergency management because they reach most segments of the population. After emergency response agencies brief the media , the media broadcasts this information through television networks, radio stations, newspapers, and websites.
- Emergency Alert System (EAS) enables the President and the heads of State and local government to provide immediate communications with the public.
- Public Access Cable Television operated by local governments can broadcast emergency information to the public.
- Cell Phones are an increasingly useful and accessible means of communication . Real-time traffic information can be broadcast directly to cell phone users who subscribe to traveler information services and travelers can use their phones to dial 511 and other information resources.
- Call Centers located at state and local agencies can provide real-time information on the status of the emergency, tips for preparedness and evacuation routes.
Traffic Control Tools. The efficient and safe management of the highway network is a critical component of successful emergency evacuations. The following tools can be used to manage highway operations in controlling traffic, assessing levels of congestion, responding and clearing incidents and optimizing traffic flow.
- Traffic Incident Management (TIM) assets enable jurisdictions to respond to incidents, which is particularly important during evacuations because of the priority on mitigating causes of congestion.
- Traffic Counting Devices are used to determine highway congestion levels. These data are relevant to decisions in regards to developing and using alternate routes and preparing for the number of people seeking shelter.
- Traffic Signals that are controlled by Traffic Management Centers (TMCs) can be optimized by TMCs for throughput on evacuation routes. Traffic signals not controlled by TMCs must be changed at the location of the intersection. Controlling traffic at intersections during evacuations may require police presence at major intersections for directing traffic. Some jurisdictions include intersection control in their emergency planning. For example, the city of Portland’s emergency management plan has provisions for controlling traffic at critical intersections.
- Traffic Signal Timing Planning for emergency evacuations ahead of time expedites operations during the actual event. An important component to preparedness is sharing signal timing plans with law enforcement so that police can prepare for changes in traffic patterns .
- Traffic Signal Pre-emption devices change the traffic signal when an emergency vehicle approaches to allow it to proceed unimpeded through the intersection.
- Ramp Meters allow for the timed entry of vehicles by stopping traffic on an interval basis, improving the efficiency of vehicles merging onto highways.
- Ramp Gates prevent traffic from entering or exiting highways are used during contraflow operations.
- Traffic Signs designate evacuation routes, contraflow patterns and the location of shelters. Flip-down signs have emergency information on the flipped-down part of the sign; the sign is flipped back up when conditions return to normal. Similarly, pre-installed signs with signs attached to their back can display contraflow information to motorists.
- Pavement Markings indicate when a road is an evacuation route or when a restricted lane can be used in an emergency.
- High-Occupancy Vehicle (HOV) Lanes can be used by non-HOV vehicles or as an ingress lane for emergency vehicles in emergencies.
- Frontage Roads with limited or controlled access and that are adjacent highways can be used by emergency vehicles.
- Reversible Lanes can be switched to accommodate travel moving in the direction of the evacuation.
- TMCs facilitate the safe movement of people and goods on surface roads during evacuations.
Assessment Monitoring and Prediction Tools. The transportation community has generated advanced computerized modeling tools that can be used in evacuation planning and operations to predict weather, estimate losses and damages from weather events, evaluate evacuation plans and model traffic scenarios, including the following.
- Clarus is an effort of the U.S. Department of Transportation’s ITS Joint Program Office and the Federal Highway Administration (FHWA) Road Weather Management Program. It is supports traffic planning by predicting weather conditions in terms of its impact on transportation.
- Consequence Assessment Tool Set/Joint Assessment of Catastrophic Events (CATS/JACE) provides disaster analysis in real time with contingency and logistical planning and consequence management. The CATS program helps assess collateral damage to facilities, resources, and infrastructure, and it creates mitigation strategies for responders.
- Dynamic Network Assignment-Simulation Model for Advanced Road Telematics (Planning version) (DYNASMART-P) is a state-of-the-art dynamic network traffic operational planning tool developed under the FHWA’s Dynamic Traffic Assignment (DTA) research project. It supports transportation network planning and traffic operations decisions through the use of simulation-based dynamic traffic assignment.
- Evacuation Traffic Information Systems (ETIS) helps forecast where emergency transportation situations may arise and uses data from previous hurricane evacuation studies to estimate probable roadway congestion.
- Evacuation Travel Demand Forecasting System. This system leverages Internet-connected sensors and cameras along roads and highways to improve the surface transportation aspect of evacuation. The system proposes efficient evacuation algorithms that dynamically generate evacuation plans for both single and multiple incidents scenarios, based on real-time traffic information obtained from sensor data available through the Internet.
- Hazard U.S. – Multihazard (HAZUS-MR2) is a software program that estimates potential losses from earthquakes, hurricane winds, and floods. Developed by the Federal Emergency Management Agency (FEMA) under contract with the National Institute of Building Sciences (NIBS), it uses Geographic Information Systems (GIS) software to map and display hazard data and the results of damage and economic loss estimates for buildings and infrastructure. Estimating losses provides a basis for emergency response and recovery planning.
- Hurricane and Evacuation (HURREVAC) is a restricted-use computer program for government emergency managers to track hurricanes and assist in evacuation decision-making for their communities.
- MASS eVACuation (MASSVAC) uses macroscopic traffic flow models to forecast hurricane evacuation performance.
- Network Emergency Evacuation (NETVAC) models traffic flow in emergency evacuation conditions.
- Oak Ridge Evacuation Modeling System (OREMS) models evacuation operations and planning and management scenarios for a variety of disasters.
- Plume Modeling Tools predict the behavior of a cloud of toxic material released into the environment.
- Sea, Lake, and Overland Surges from Hurricanes (SLOSH) is a computerized model run by the National Hurricane Center (NHC) to estimate storm surge heights and winds resulting from historical, hypothetical, or predicted hurricanes.
- Traffic Estimation and Prediction System (TrEPS) analyzes real-time traffic data from different sources to select strategies for meeting traffic control, management, and operation objectives.
These tools can improve evacuation operations in communications, traffic control and assessment and monitoring. They can be used in the readiness, activation and operations phase of the evacuation. To be used effectively as possible, evacuation plans should identify which tools are available in the jurisdiction and how they can be used most effectively. By planning ahead, emergency management can use transportation tools to improve the safety, mobility, and efficiency of emergency evacuations with advance notice.
Using Highways During Evacuation Operations for Events with Advance Notice: Routes to Effective Evacuation Planning Primer Series
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