Asset Management

Pavement Health Track Graphical User Interface, User's Guide

Purpose

This program estimates the Remaining Service Life (RSL) for the highway sections described in the Highway Performance Monitoring System (HPMS) database maintained by the FHWA.

The source data for the Pavement Health Track (PHT) analysis tool is based on the HPMS 2010 format text file (see Table 12) and/or available electronic databases. The PHT tool acquires data from the external data sources and compiles a set of highway data made up of the data fields required for the PHT analysis. Each record in the highway data represents a highway section. The compiled highway data is permanently stored in the database for subsequent use in the PHT analysis.

Estimating RSL

Pavement RSL at the project level typically is defined as life of a pavement from the present time until application of the first significant rehabilitation treatment or reconstruction, which would be the first significant cost expenditure for the pavement. The placement of a structural overlay or reconstruction signals the end of a pavement's serviceable life; the application of minor maintenance treatments or thin overlays is not considered significant enough to indicate the end of service life.

Significant rehabilitation occurs due to some form of pavement failure. Failure typically is described as the pavement attaining first terminal distress as shown in Figure 1. Thus, RSL is simply the time in years or remaining ESALs that it would take a given pavement to attain the first terminal distress.

Figure 1. Predicted Pavement Distress and Estimated RSL

Critical RSL

The critical RSL is the estimated time until the first terminal distress occurs. Using the example illustrated in Figure 1, the critical RSL is estimated as shown in Table 1. In this example, the first terminal distress is cracking, which occurs at 15 years, since the pavement's current age is 10 years; the RSL is the difference of 5 years.

¹A spalling RSL model is not currently implemented.

Weighted Average RSL

The weighted average RSL is the estimated time until each terminal distress occurs averaged together using a user defined weight for each distress type. Using the example illustrated in Figure 1, the weighted average RSL is estimated as shown in Table 2. In this example, each distress type is assigned an equal weight in the average calculation, resulting in an average RSL of 10.5 years.

¹A spalling RSL model is not currently implemented.

Calibrating the RSL Estimation

Local calibration of the RSL estimations of the pavement performance models will be done as presented by the steps below. An example of an adjusted RSL predicted faulting using the MEPDG computational model is shown in Table 3 and Figure 2.

1. Develop project-specific future estimates of pavement distress/IRI.
2. Assemble historic measured project-specific distress/IRI.
3. For the period with historic performance data, make a detailed comparison of predicted and actual pavement performance and determine the exact relationship (constant, linear, non-linear, etc.) with the RSL pavement performance predictions.
4. Based on the relationship determined in step 3, develop calibration, adjustment, or scaling factors for use in minimizing error between measured and RSL predicted distress/IRI.

Figure 2. Adjusted RSL Predicted Faulting