When creating a map layout, what is the best reasoning for including a scale bar?

Including a scale bar in a map layout is essential primarily because it enables viewers to measure distances accurately. This is crucial for interpretation and analysis, especially when users need to gauge real-world distances from the map representation. A scale bar provides a visual reference that corresponds to actual distances on the ground, ensuring that viewers can make informed decisions or conclusions based on accurate distance measurements.

While aesthetics and compliance with mapping standards may contribute to the overall quality and professionalism of the map, they do not serve the primary function of helping users understand the relationships and distances in the geographic data presented. Additionally, while a scale bar may offer some context regarding the geographic extent of the layer, its main purpose is to facilitate distance measurement, making it an integral component of a functional map layout.