Which type of projection is primarily used to preserve distance?

An equidistant projection is specifically designed to maintain true distances from one or more points on the map to all other points. This characteristic makes it particularly useful for certain applications where accurate measurements of distance are essential, such as in navigation or for calculating travel distances between locations.

In equidistant projections, distance relationships are preserved, allowing for reliable calculations. This differs from other types of projections. For instance, azimuthal projections focus on maintaining direction from a central point but do not necessarily preserve distances. Conformal projections are primarily aimed at preserving angles and shapes, resulting in distortion when measuring distances. Equal-area projections, on the other hand, maintain accurate area representation, but they sacrifice distance fidelity, which is not suitable for applications where distance accuracy is critical.

Thus, the nature of equidistant projections makes them the correct answer in this context, as they are explicitly designed to keep distances accurate across the map, enabling effective spatial analysis and planning.