When should traffic control devices such as cones or flares be deployed at a scene?

• A. They must be placed across all lanes.
• B. To establish a perimeter and direct traffic away from the scene when appropriate.
• C. Only if a supervisor is present.
• D. Never use them; rely on police trucks.

Answer: (B)

At an incident scene, the priority is to create a safe working space and keep approaching drivers away from hazards. Deploying traffic control devices like cones and flares serves to establish a perimeter around the scene, provide a visible buffer for responders, and direct traffic onto safer paths. By warning motorists early and guiding them away from the work area, you reduce the risk of secondary crashes and give crews room to operate.

The placement and number of devices depend on factors such as road type, traffic volume, weather, and visibility, but the goal remains the same: warn and channel traffic away from the scene when appropriate. This approach is preferable to blocking every lane or waiting for a supervisor, and it’s safer than relying solely on police vehicles without using planned traffic control measures.