The pavement condition index, or PCI, is a measurement of pavement grade or condition and ranges from 0 to 100. A newly constructed road will have a PCI of 100, while a failed road will have a PCI of 25 or less. The pavement condition is primarily affected by the climate, traffic loads and volumes, construction materials and age. The symptoms manifested by the pavement as it ages or fails are determined by the distress types that are present, such as fatigue or alligator cracking, rutting etc.
Briefly, good to excellent pavements (PCI>70) are best suited for pavement preservation techniques, (e.g., preventive maintenance treatments such as chip seals or slurry seals). As pavements deteriorate, treatments that address structural adequacy are required. Between a PCI of 25 to 69, hot mix asphalt (HMA) overlays are usually applied at varying thicknesses. This may be accompanied by milling or recycling techniques.
Finally, when the pavement has failed (PCI<25), reconstruction is typically required.