What does a profile in a route survey illustrate?

A profile in a route survey primarily illustrates a side view of the route's longitudinal surfaces, showing how the elevation changes along the length of the route. This allows surveyors and engineers to understand the terrain, including peaks, valleys, and grades that will affect construction and movement along the surveyed path. By presenting this vertical representation, a profile helps in planning for drainage, cut and fill areas, and other critical design aspects. This visualization is essential for assessing potential challenges and for engineering the route appropriately.

In contrast to other options, a top view of the land would represent a plan view rather than elevation changes, which does not convey the necessary longitudinal details needed for understanding the route's grade. A map of utilities and services focuses on infrastructure rather than the physical characteristics of the terrain, and a historical view would not provide the current elevations or contours needed for practical route planning. Thus, the profile provides the most relevant and actionable information regarding the vertical landscape of the surveyed route.