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Enhancement of the Pavement Health Track (PHT) Analysis Tool Final Report

PHT Analysis Log System


A comprehensive log system is useful to explain and document the analysis process to aid in understanding of the results and the inputs and conditions that affected it. The objective of this task was to develop a log system for the PHT Analysis Tool to create a process history log that records errors, warnings, and key actions that occur during the analysis.

The log system for PHT analysis engine collects and records key information for each PHT step during the run-time analysis, and provides a sequential log file for the whole analysis procedure. The information in the log file contains

  • Information Messages about input data, process steps, and key processing results
  • Warning messages about unusual input data and processed results
  • Error Messages about invalid input data, recoverable and critical analysis errors

The log information provided by the log system is beneficial to both PHT users and developers. As a PHT user, the information can be used to trace each key analysis step, understand the engineering process, verify analysis result during each step, and identify potential issues caused by input data. To PHT developers, the information can be used to assist the program debug, identify programs bugs, and improve the code maintenance efficiency.


Data communication between PHT user interface and PHT analysis engine is through an in-memory dataset. However, the log information size can be very big and it is not efficient to pass the log information by dataset or through computer memory. Rather, the log system generates a log file and PHT user interface reads and interprets the log file for log information. There are three types of log message:

  • Info: Information, function start/end, input data, output result
  • Warning: Warning information, uncommon input data or analysis result
  • Error: Error information, invalid data range/format, invalid analysis result

The PHT log system records the following information.

  • PHT analysis start
  • Total projects number
  • Current project Analysis start
  • Input data verification for current project (data range, and data format)
  • Default data selection for current project
  • EASLs and distress calculation for each year
  • Distress correction with historical data
  • Terminal value, age, and ESALs for each distress
  • Overall RSL, distress, and ESALs
  • Current project analysis end
  • PHT analysis end

The log files generated by the PHT analysis are stored on the systems hard drive and are referenced by the PHT analysis results stored in the PHT database. By default, all the analysis log files are stored in the following directory:


The following excerpt of the PHT log for the analysis of a highway section illustrates some of the types of messages that may appear in the log system.

Record Index: 1
<Info> ID = 1
<Info> YearRecod = 2011
<Info> StateCode = 4
<Info> data check passed
<Info> The maximum service life=15
<Info> ACType = 4
<Info> Precipitation = 11.3
<Info> FI = 53.9
<Info> FTCYC = 51.7
<Info> GMT = 40
<Info> AverageTemperature = 65.24166
<Info> AirVoid = 5.14
<Info> EffectBinder = 9.86
<Info> base modulus = 1500000
<Info> Clay_Percents = 6.1
<Info> Sand_Percent = 42.4
<Info> Silt_Percent = 14.2
<Info> Overall RSL Age =5, Accumulated ESALs=1.062762E+07
<Info> DistressType=2, Terminal Value=20, MaxServiceLife=46
<Info> DistressType=2, Terminal Age=46, TotalESALs=97774080
<Info> DistressType=0, Terminal Value=170, MaxServiceLife=46
<Info> DistressType=0, Terminal Age=46, TotalESALs=97774080
<Info> anaylsis succeeded for this project

The use of the log system has a negative impact on the overall runtime of the PHT analysis and is therefore disabled by default. When fully enabled for all logging, the overall analysis runtime increases on average of about two fold as shown in Figure 67.

A vertical bar chart plots values for run time associated with processing data for 2,252 highway sections without logging and with logging. The value for runtime without logging is 193 seconds; the value for runtime with logging is 401 seconds.
Figure 67. PHT Runtime Benchmarks with/without Logging

Graphical User Interface

The PHT log system is controlled from Logging tab of the PHT Properties dialog window as shown in Figure 68. This window is used to enable the PHT analysis logging capability and to specify the level of logging to be captured. When logging is enabled, the level of logging indicated will be captured; however, logging can significantly increase the analysis runtime and should be disabled when the log is not of interest.

A screen shot shows the options under the logging table of the PHT Properties window. Enable PHT Analysis Logging is a selected or deselected field. If selected, the user has three radio buttons: capture only error message logs, capture error and warning message logs, and capture error, warning, and informational message logs.
Figure 68. PHT Properties - Logging

When an analysis log has been captured, the logging for the analysis for each individual highway section is available on the Log tab of the PHT results window. The Log tab in the vertical panel of the Result Viewer is only available if a log file has been captured during the analysis and is available for display as shown in Figure 69.

A screen shot shows a sample log in a vertical window that is associated with the analysis of a specific highway section that is selected in an adjacent vertical window.
Figure 69. PHT Logging User Interface
Updated: 11/22/2013