A toolkit for anticipating & comprehensively evaluating transportation project impacts.


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PET is a freely available, open-source transportation project evaluation toolkit that assesses impacts across a variety of project types. Developed by Dr. Kara Kockelman, graduate students Dan Fagnant & Brice Nichols, Dr. Steve Boyles, and post-doc Dr. Chi Xie, at the University of Texas at Austin, under a Texas Department of Transportation (TxDOT) research project, PET uses existing traffic link counts, behavioral functions, & travel growth projections to estimate changes in travel patterns for multiple traveler classes as a result of construction projects and transportation policy changes. PET quickly estimates how network changes affect benefits & costs to travelers, project financing feasibility, air quality, and crash totals. Summary measures (such as net present values and benefit-cost ratios) are developed over multi-year/long-term horizons to quantify the relative merit of project scenarios, versus a base-case (e.g., no-build) scenario.  Click  here for a video look at PET's motivation & GUI.

PET offers valuable predictions of future flow patterns and transportation benefits, enabling transportation planners and decision makers to quickly, quantitatively and objectively compare complicated project alternatives. This ability is particularly crucial as budgets become increasingly constrained, making optimal investment and policy decisions paramount. Additional PET capabilities include sensitivity analysis (for simulating uncertainty across most inputs) and a knapsack-type optimization module for budget allocation under a variety of constraints (across project alternatives). PET default values are consistent with federal guidelines for use in Projects of National and Regional Significance (and with past TIGER grant applications) to facilitate grants through the MAP-21 program, and parameter values are easily modified to suit local conditions and priorities.

PET-Assessed Project Impacts Include

  • Traveler Welfare (consisting of operating costs and changes in travel time)
  • Travel Time Reliability (based on the valuation of travel time variance)
  • Crash Counts (by severity)
  • Emissions (14 pollutant species)
  • Tolling Revenues
  • Fuel Use
  • Link-level Volumes & Speeds by Time of Day

Supported Transportation Project Types

  • Capacity Expansion and Grade Separation
  • Tolling (Pricing can vary by mode, user class, and time of day)
  • Shoulder Lane Use
  • Reversible Lanes
  • Ramp Metering
  • Transit Route & Headway Changes
  • Work Zone Phasing/Scheduling
  • Traffic Safety Projects
  • Advance Traveler Information Systems
  • Variable Speed Limits (Speed Harmonization)
  • Incident Management
  • Changes to Parking & Other Fixed Trip Costs

This website provides an array of PET-related information, including pre-coded transportation networks for Austin, Dallas-Ft. Worth, & Houston, Texas. Moreover, it offers all uncompiled C++ and Visual Basic codes and supporting documentation. Interested parties can download the model and run PET using the existing Austin, Dallas-Ft Worth, or Houston networks -- or code new networks to develop and assess projects for their particular region of interest. Please note that PET is developed to handle up to approximately 300 directional links at high computing speeds, but can be adapted to handle more. Please be sure to read the linked User's Guide for instructions.

The code is copyrighted to Kara Kockelman and associated investigators.  As an open-source program, all use of codes, original or modified or extended, must be freely shared with others, and appropriately referenced.  We look forward to hearing about your applications of PET!  And we welcome questions.



Visit Dr. Kockelman's Homepage

Last Updated: 7.24.14