Utah Travel Models Free-Flow Speed Research

Details

• Creators:
  Hooper, Ivan ; Bassett, David ; Abel, Emma ; Gee, Collin
• Corporate Creators:
  Avenue Consultants, Inc
• Corporate Contributors:
  Utah. Department of Transportation. Research and Innovation Division ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  • Travel demand
  • Free flow speeds
  • Traffic
  • Speed and delay studies
  • Data analysis
  • Geographic information systems
  • Travel Modeling
  • Speed Research
  • Traffic Research
  • Speed Study
• Publication/ Report Number:
  UT-24.24 ; UT23.405
• Resource Type:
  Tech Report
• Geographical Coverage:
  Utah ; United States
• Edition:
  Final Report Jan 2024 to November 2024
• Corporate Publisher:
  Utah. Department of Transportation
• Abstract:
  Utah’s six travel demand models (TDM) are essential tools for the state’s transportation planning. Virtually every transportation plan and environmental study uses the TDMs to develop and evaluate transportation solutions, making the TDMs the most important transportation planning tool in the state. Currently, all of the TDMs employ a similar methodology to estimate link-level free-flow speeds which have been in use for more than 20 years. However, UDOT has never fully vetted this methodology and compared it to observed travel speeds in areas outside of the Wasatch Front metropolitan planning area. With accessible statewide speed data now available, UDOT can conduct this research with the goal of improving the accuracy of the TDMs. The objective of this research is to determine the accuracy of the methodologies and data used to estimate free-flow speeds in the six Utah TDMs and recommend any improvements to those methodologies. The research team performed a comprehensive GIS-based comparison analysis of free-flow model speeds and observed free-flow speeds that were obtained from UDOT-owned datasets. These datasets were then joined to form a common dataset. The data was cleaned and then filtered based upon various data combinations including the TDM, roadway type, and area type. Researchers made several findings using the aggregate statistics created for these combinations. Findings suggest a high variety in speed-difference results between the TDMs and real-world speeds in rural areas. Smaller models seem to perform better than larger, state-level models. Speed factors help to improve accuracy in the models. Some issues apparently exist in model functional types, which may warrant review. The research resulted in the development of a series of recommendations which may help enhance future TDM performance.
• Format:
  PDF
• Funding:
  24-8367
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/81964/dot_81964_DS1.pdf
• File Type:
  [PDF - 4.43 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:119ceb1d7809847a6ac407bc64caef6a596a23cbd0f847562558e7dbbdadcbafa44eba53ab81edc5b8497918abf87f373316a2de441485b4b26121a363f2ef7c