Abstract Manager

Major emergencies such as hazmat releases, wildfires, and nuclear incidents create intense, short‑duration demands on urban transportation networks. For transportation professionals, the core challenge is bridging planning‑level evacuation analysis with real‑time decision making and operations. This presentation synthesizes lessons from recent evacuation planning work the Greater Toronto Area, and most recently, Denver Colorado, emphasizing practical decision support based on best practices and data analysis/transportation modeling.

The work is grounded in traditional traffic engineering and network assessment—identifying critical evacuation corridors, key freeway ramps, grade crossings, and arterial bottlenecks—and then stress‑testing these against plausible emergency conditions such as plume exposure, wildfire growth, or rail hazmat events. These transportation insights are combined with extensive consultation with emergency management practitioners, police and fire services, road maintenance crews, and transit agencies to ensure that traffic measures are feasible under real emergency constraints and to identify opportunities and constraints in improving evacuation efficiency.

The presentation translates these findings into a staged, operations-oriented planning framework to support time-sensitive decision-making during extreme events. Key elements of this framework include:

1. Evacuation planning and prioritization, defining who evacuates, who remains in place, and the sequencing of evacuation through staged or ring/keyhole (plume-based) strategies.
2. Transportation network operations, providing clear recommendations on what actions to implement, where, and in what order—ranging from background traffic reduction to high-impact, low-complexity measures such as favoring outbound signal progression.
3. Real-time monitoring and operational triggers, establishing thresholds based on observable field conditions, and linking those thresholds to predefined, coordinated operational responses.

Examples of decisions supported by this framework include whether to shelter in place or evacuate, how to manage shadow evacuation demand, which traffic management strategies to deploy and with what resources, and how to safely and efficiently reintegrate traffic and displaced populations during recovery.

Decision-making within this framework is driven by observable field conditions (e.g., speeds, queues, spillbacks, blocked crossings) and hazard indicators (such as plume direction, fire spread, and rail perimeters), each linked to predefined operational responses. The conclusions emphasize transferable best practices from emergency evacuation research, including the use of monitoring-based action thresholds within emergency plans and improved integration between transportation operations and emergency management to enable timely, resilient decisions during extreme events.