Pavement Condition Indexes

Understanding PCI
 
  • PCI Rating - total deduct value (sum of each deduct) subtracted from 100
  • Total for each distress type and severity (21)
  • Count the number of distress type & severity combinations with a deduct value greater than 5
    		•
    PCI Calculations
     
  • Collect field data - severity, type, quantity.
  • Each distress type and severity are summed and percentages calculated.
  • Determine deduct values from the deduct curves
  • Compute total deduct value - TDV = a+b
  • Adjust total deduct value -
  • Compute PCI - PCI = 100-cdv
    		•
    Sample Calculation
     
  • Asphalt surface is 24 feet wide and 100 feet long
  • Distresses Identified:
  • 200 sq./ft - Low - Alligator Cracking
  • 400 sq./ft - Medium- Alligator Cracking
  • 24 linear/ ft- Low - Transverse Cracking
  • 200 sq./ft- Low - Rutting
    		•
    The densities for each of these distress types/severity
     
  • Divide the affected area by the area of the inspection unit
  • Density = (density/area) x 100
  • Low Alligator Cracking = (200/2400)*100 = 8.3%
  • Medium Alligator Cracking = (400/2400)*100 = 16.6%
  • Low Transverse Cracking = (24/2400)*100 = 1 
  • Low Rutting = (200/2400)*100 = 8.3%
    		•
    Alligator Cracking - Low - 8.3 percent = 30 points
    Alligator Cracking - Med - 16.6 percent = 51 points
    Transverse Cracking - Low - 1 percent = 3 points
    Rutting - Low - 8.3 percent = 25 points
    Corrected PCI
     
  • The total-deduct value is 106 points.
  • This deduct must be corrected for multiple occurrences.
  • The total numbers of distress & severity combinations with deduct values greater than 5 is 3. So q=3.
    • Enter the deduct value of 106 and going with curve 3.
    • The corrected deduct value of 68.
    • The PCI value is 100 minus 68 = 32.
    PCI for Management Sections
     
  • If there is only one inspection unit for the management section, the PCI of that one unit will represent the whole management section.
  • If there are multiple inspection units, they must be combined to provide the PCI of management unit
    • Multiple PCI Calculations
     
    With Special Sections