Design hour volume (DHV) is used to assess capacity and safety for the design year.

Answer: C — To assess capacity and safety for the design year

Design hour volume is the forecasted peak-hour traffic for the design year, used to test how the roadway and its intersections will perform once growth is included. By projecting the highest expected load in that hour, engineers can judge whether there will be enough capacity and whether safety margins will hold, guiding decisions on lane counts, geometry, and control strategies for the project year. It’s about ensuring the design accommodates future demand, not just current conditions or ancillary planning like signage, markings, or parking demand.