Which type of sheet shows directional arrows?

Answer: C — Plan or key sheets

The correct answer is that plan or key sheets are the type of sheets that illustrate directional arrows. These sheets provide a simplified view of the project layout, showing the overall configuration of the roadways and their relationship to existing features. Directional arrows on these sheets guide users in understanding traffic flow, lane designations, and proposed alignments, making it easier to visualize how the different components of the project will interact. In contrast, typical section sheets focus on the cross-section of the roadway, detailing materials and dimensions but generally do not include directional information. Profile sheets display the elevation changes along a centerline and are primarily concerned with vertical alignment rather than directional flow. Cross-section sheets illustrate horizontal slices of the roadway at particular stations, providing details on the cuts and fills involved in construction, again without the directional context. This distinction highlights the unique role of plan or key sheets in conveying directional flow in highway design.