Deterioration Rates

These fields (pictured below) allow you to create deterioration slopes for each combination of street pavement type and classification. These slopes are then used to determine PCI in the model runs. For additional information on how each field is used, consult the table at the bottom of the screen.

deterioration

Note: Only one Deterioration setting is required; all others are optional. The software provides the first and last two points on the curve.

Field Name

Description/Use

Initial PCI (Pavement Condition Indices) Rating and Starting Year

The Initial PCI is always set to 100 and the Starting Year is always set to 0. This indicates the best possible condition for the street at the time it is created.

Note: Over time, the street will deteriorate. You can create your deterioration slopes using the fields provided below.

PCI 1-6

These fields allow you to include PCI values as they diminish from 100. This is used to calculate the deterioration slope.

Year 1-6

These fields allow you to include year values as they increase from 0. These fields correspond with the PCI values on the left and represent each year the PCI value will change. These are also used to calculate the deterioration slope.

Deterioration Slopes

The various points along the curve are calculated by the system. These use the user-entered PCI and Year values. Only one deterioration setting is required; all others are optional. The system provides the first and last two points on the curve.

Penultimate Rating and Ultimate Rating (PCI)

The PCI values have a penultimate rating of 1 and an ultimate rating of 0. This means that calculated PCI values in Field Inspections cannot be lower than 0. In order to save PCI values in this module, you cannot enter a value less than 1.

Penultimate Year and Ultimate Year

The year values have a penultimate year of 100 and an ultimate year of 1000. This means that the calculated year cannot be greater than 1000. In this module, you cannot enter a year of 100 or greater.

Penultimate Slope and Ultimate Slope

The penultimate slope is calculated by the system based on the last year input and the penultimate year. In our example below, the last year input was 30. Thus, the penultimate slope is equal to 0.003. The ultimate slope is always equal to 0.0011. This means that the street's deterioration slope can never be less than 0.0011.