The present serviceability index (PSI) is a pavement performance measure. Introduced by the
(AASHTO), the PSI is one of the most widely used pavement performance indicators after
pavement condition index (PCI) and
international roughness index (IRI).
This performance indicator ranges between 0 and 5, 0 representing a failed pavement and 5 an excellent one. Since the PSI entails slope variance, it is correlated with
performance indicators related to roughness such as IRI.
History
The PSI was developed based on the
AASHO Road Test
The AASHO Road Test was a series of experiments carried out by the American Association of State Highway and Transportation Officials (AASHTO), to determine how traffic contributed to the deterioration of highway pavements.
Methodology
Of ...
's
present serviceability rating
The present (or here'' and ''now) is the time that is associated with the events perceived directly and in the first time, not as a recollection (perceived more than once) or a speculation (predicted, hypothesis, uncertain). It is a period of ...
(PSR).
AASHO Road Test
The AASHO Road Test was a series of experiments carried out by the American Association of State Highway and Transportation Officials (AASHTO), to determine how traffic contributed to the deterioration of highway pavements.
Methodology
Of ...
was a set of experiments carried out by the
AASHTO from 1956 to 1961. Unlike the PSR, which was a ride quality rating that required a panel of observers to ride in a car over the pavement of interest, the PSI does not require a panel of experts. Therefore, it was a more practical approach for large-scale pavement networks.
Calculation
Present serviceability is a function of several variables. For
flexible pavement
Highway engineering is an engineering discipline branching from civil engineering that involves the planning, design, construction, operation, and maintenance of roads, bridges, and tunnels to ensure safe and effective transportation of people and ...
these variables include:
* Slope variance (SV)
* Depth of
rut (RD)
*
Cracking and patching (C+P)
References
{{Road types
Pavements
Pavement engineering