Which of the following is NOT a required component for safety warning devices?

A portable fire extinguisher is not a required component for safety warning devices used in the event of a roadside emergency. Instead, the primary focus of safety warning devices includes items that signal to other drivers and ensure their awareness of a potentially hazardous situation.

Three red electric lanterns, three fusees, and two red flags are all essential for marking the location of a vehicle that has broken down or is stopped on the roadway. The red lanterns or fusees serve as visual warnings to approaching vehicles, while the red flags enhance visibility during daylight conditions.

The absence of the portable fire extinguisher in the list of required components highlights that while safety equipment is crucial, the specific regulations for safety warning devices focus more on visibility and signaling rather than on fire prevention. Therefore, the choice of a portable fire extinguisher, although important for general safety in various situations, does not fall under the mandatory items for safety warning devices in the context of a vehicle emergency.