What is the most reliable way to determine how far to extend actual evacuation distances?

Detection equipment is the most reliable method for determining evacuation distances because it provides precise and quantitative measurements of hazardous substances in the environment. These tools can assess the concentration of toxic gases, radiation levels, or chemical spills, allowing responders to understand the specific risks associated with an incident.

Detection equipment can enhance decision-making during emergencies by offering real-time data about the type and severity of the hazard. This enables officials to set accurate evacuation zones based on objective information rather than relying on subjective judgments or assumptions.

The other options, while useful in certain contexts, do not provide the same level of reliability. Visual assessments can be misleading depending on the conditions and may not accurately reflect the presence or concentration of a hazardous material. Public feedback can indicate perceptions of danger but lacks the scientific basis required for effective decision-making. General guidelines serve as helpful starting points but may not account for the unique circumstances of each incident, making them less reliable than data obtained from detection equipment.