Final answer:
Emergency vehicle markings are most effective for conspicuity when they are highly visible and easily recognizable.
Step-by-step explanation:
Emergency vehicle markings are most effective for conspicuity when they are highly visible and easily recognizable. These markings include flashing lights (red, blue, and white), sirens, and reflective materials. The combination of these elements ensures that emergency vehicles are easily noticed and provide a clear warning to other drivers and pedestrians.