Design Hourly Volume
2.12        
    Current 10 Years
    Year Later
    b c
     
ADT 6915 9660
  K    
Source 30th Highest Hour 15.0% 1037 1449
Figure 2.12, page 50 10th Highest Hour 17.5% 1210 1691
AASHTO Exhibit 2-28 Highest Hour 24.0% 1660 2318 Capacity Exceeded
Capacity   2000 2000
Roadway Design Engineers usually use the K30 DHV for Design and Analysis
Traffic Engineers usually use the Peak Season PM Peak Hour for Design and Analysis
This roughly corresponds to a K100 DHV
Why do we do this?  Data is much easier to get.
K30 = V30 / AADT
Example: K30 = 1500 / 10,000 = 15%
AADT = Average Annual Daily Traffic (a continuous count for the entire year)