The University of Tennessee, Knoxville


TTAP Newsletter: RoadTalk

How about some Transportation Planning??

by Dr. Airton Kohls (Source: Federal Highway Administration)

You may have noticed that TTAP has enhanced its continuing education program by updating and developing new workshops. We have focused in the area of Transportation Planning, offering workshops like Traffic Access Management and Planning for Special Events. Right now we are developing workshops on Planning for Operations, School Site Planning and Traffic Impact Analysis. For our training calendar, please go to:

In the mean time I would like to share some interesting information and tools that I found on the FHWA Travel Model Improvement Program webpage -

The Travel Model Improvement Program (TMIP) has conducted research, provided technical assistance, and delivered training to local, regional and state transportation planning professionals since 1994. Much has changed over this period, with shifts in transport policy, advances in modeling theories, and progressions in practical lessons. Throughout, TMIP has worked to advance modeling capabilities and support transportation professionals as they respond to current and future challenges. Today, TMIP continues its mission of improving analysis practices to ensure that transportation professionals are well equipped to inform and support strategic transportation decisions.

Smart Growth Area Planning Tool
Developed through the second Strategic Highway Research Program (SHRP2), the Smart Growth Area Planning tool (SmartGAP) provides planners with scenario-forecasting tools that allow them to estimate smart growth strategies impact on peak-hour transportation, as well as its effects on sprawl, energy reduction, active travel, and carbon footprints.

The SmartGAP tool allows a user to test different scenarios for land use, population growth, and transportation strategies, and then evaluate their effects on several significant performance measures. SmartGAP tracks individual households and firms in a region to determine transportation impacts from growth. The tool has several advantages:

  • Requires relatively low-resolution inputs,
  • Is based on high quality science,
  • Can handle complex interactions,
  • Allows for a rapid configuration of scenarios,
  • Provides numerous performance measures, and
  • Is FREE, open-source, and user-friendly.

SmartGAP considers 13 built environment place types and features that address the complexity of land use and transportation interactions:

  • Congestion impacts – Accounts for recurring and nonrecurring congestion on local streets, arterials and freeways as a function of smart growth and vehicle miles travelled (VMT) from autos, trucks and buses.
  • Induced demand – Forecasts the change in VMT for each household due to changes in urban form as well as the short and long term induced demand effects.
  • Transportation policies – Forecasts the change in VMT for each household due to various transportation policies, such as pricing, intelligent transportation system strategies, and vanpool, telecommuting, ridesharing and transit pass subsidy programs.

SmartGAP is a decision support tool for planners to test smart growth scenarios and evaluate their impact on travel demand. The software is designed to be accessible to land use and transportation planners with no modeling experience. In certain cases, the tool can be applied to supplement more sophisticated modeling methods.

Results from the pilot tests indicate that:

  • Performance measure outputs were consistent with expectations,
  • Installation and input file preparation were easy,
  • Regional policy scenario testing is useful for: (a) smaller MPOs, local jurisdictions without advanced travel demand models, and (b) bigger MPOs, state agencies to pre-screen policy scenarios before undertaking extensive travel demand modeling, and
  • Model run times are reasonable.

SmartGAP software: The tool is available on the SHRP 2 Web Site.
For the final report, software, and user’s guide visit:

R software: SmartGAP was developed in R, an open source statistical software platform, and therefore must be installed on the user’s computer prior to running the tool. R is available at:

For additional information on Smart Growth Area Planning Tool please contact Sarah Sun at