Design Hour Volume
Levels of service are calculated using the design hourly volume (DHV). The DHV for intersections is the traffic flow that occurs during the peak traffic hour on an average day. Typically, traffic counts at intersections are obtained through manual counts in order to capture the volumes of the turning movements and should be conducted in 15-minute intervals. The design-hour volume most often occurs during the morning or afternoon when motorists are commuting to or from work. For typical military installations, an average day would be during the workweek on a Tuesday, Wednesday, or Thursday.