KY MUG An Overview of Post Processing Routines

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KY MUGAn Overview of Post Processing Routines

• The Corradino Group
• February 25, 2005

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Topics

• What is a post-processor?
• How are they implemented?
• Examples

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What is a Post-Processor?

• A script or procedure that uses model results and
  other data or procedures to develop additional
  data and analyses that the model itself cannot
  produce.

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How Are They Implemented?

• Program as a GISDK Script
• Integrate with external procedures
• Use a database reporting program like Crystal
  Reports

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Examples

• Highway Evaluation
• Root-mean-square error
• Cost estimation and forecasting
• Air quality

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Highway Evaluation

• Number of Links and Percentages
• Percentage of Links with Counts
• Total Lane Miles, Directional System Miles
• Average Link Length Using System Miles
• Total VMT, VHT and Loads Using Volumes on Links
  With Counts
• Ratio of Volume Over Count VMT, VHT and Loads
• Total Volume on All Links

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Highway Evaluation (cont.)

• Volume Percentages on All Links
• Average Total Volumes on All Links
• Total VMT and VHT for All Links Using Volumes
• Original and Congested SPEEDS (MPH) and Percent
  Change
• Screenline Summaries

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Highway EvaluationSystemwide

• Number of Links
• System Miles
• Lane Miles
• Directional Miles
• VMT Using Volumes
• VMT Using Counts
• VMT V/C

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Highway EvaluationSystemwide (cont.)

• VHT Using Volumes
• VHT Using Counts
• VHT V/C
• Volumes All Links
• VMT All Links
• VHT All Links
• Original Speed (mph)
• Congested Speed (mph)
• Average Total Volume

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Report of Screenlines
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Root-Mean-Square Error

• RMSE 34.616 FOR COUNT RANGE 0. TO
  5000. 45 - 55
• RMSE 23.946 FOR COUNT RANGE 5000. TO
  10000. 35 - 45
• RMSE 22.541 FOR COUNT RANGE 10000. TO
  20000. 27 - 35
• RMSE 19.812 FOR COUNT RANGE 20000. TO
  30000. 24 - 27
• RMSE 25.878 FOR COUNT RANGE 0. TO
  400000. 32 39

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Evaluation Routines

• Percent Root-mean-square error
• By volume group
• By roadway type
• VMT ratio by AT, FT
• HPMS observed VMT.

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Count Estimation and Factoring

• TransCAD ODME
• Factor by modeled growth
• Process to wash-out model error.
• Typical Estimated Counts at RMSE lt15
• Apply model growth to estimated counts for
  project level traffic
• Counts must be consistent
• Doesnt work for new roads on new alignment

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Air Quality Analysis

• VMT by HPMS functional class
• Tabulate by Functional Class
• Length load VMT
• Some processes also estimate speed.

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QUESTIONS?

• ?