What kind of views do the bottom halves of most plan and profile sheets show?

The bottom halves of most plan and profile sheets typically show profile views of the proposed highway. This is essential for understanding how the highway will interact with the existing terrain and any elevations or depressions in the land. The profile view illustrates the vertical alignment of the roadway, depicting changes in grade, elevations at various points along the highway, and any critical design features such as grades or vertical curves. This information is vital for engineering purposes, as it directly impacts drainage, sight distance, and vehicle operation along the roadway.

The other types of views mentioned do not accurately describe what is displayed in the bottom halves of plan and profile sheets. Cross-sectional views focus on slices through the terrain to show the relationship between different elevations at specific points. Bird's-eye views provide an overhead perspective of the entire project, which differs from the linear representation offered in profile views. Lastly, topographical charts present detailed information about the terrain's features, such as contours and elevation changes, but they serve a different function than the detailed profile representation of the highway alignment found in plan and profile sheets.