Using Vehicle Probe Data to Evaluate Speed Limits, Year 3

Details

• Creators:
  Fitzpatrick, Kay ; Kutela, Boniphace ; Le, Minh ; Venglar, Steven
• Corporate Creators:
  Texas A&M Transportation Institute
• Corporate Contributors:
  Texas Department of Transportation. Research and Technology Implementation Office ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  • Speed zones
  • Speed data
  • Traffic lanes
  • Data collection
  • Traffic law enforcement
  • Speed limits
  • Freeways
  • Transportation corridors
  • Speed Zone Studies
  • 85th Percentile Speed
  More +
• Publication/ Report Number:
  FHWA/TX-2/0-7156-01-R1
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Texas
• Edition:
  September 2022-June 2026
• Corporate Publisher:
  Texas A&M Transportation Institute
• Abstract:
  Speed limits are among the most visible and routinely enforced traffic control devices motorists encounter in their everyday driving. Speed limits are set using speed zone studies. This research project investigated how to make speed zone studies and speed zone decisions more effective and efficient. Researchers explored the thresholds for speed zone factors, applying the previously developed suggested speed limit based on a probe data (SSL Probe ) protocol for corridors to determine if improvements are needed. Researchers also used the findings from these efforts to refine the guidelines on how to use probe data within a speed zone study. The SSL_ Probe protocol was used to estimate the 85th percentile speed needed for a speed zone study for 32 freeway corridors and 246 non-freeway corridors. The suggested speed limits based on the estimated85th percentile speeds were similar to the suggested speed limits identified using on-site speed data or were generally within 5 mph. While the Texas Department of Transportation (TxDOT) Procedures for Establishing Speed Zones manual would need to be revised prior to being able to use probe data in a speed zone study, the use of these predicted 85th percentile speeds can provide a quick check on the need for a speed zone study. Based on discussions with TxDOT staff, reviews of other recent research studies, and the research team's engineering judgment, researchers suggest new factors for use in a speed zone study.
• Format:
  PDF
• Funding:
  0-7156-01
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/93219/dot_93219_DS1.pdf
• File Type:
  [PDF - 1.35 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:9bcf149b80bba6e4eebe70f21b162f7b2e8aee3d7ea558826cc7856948dbd9590cf8b0241790814f9e8408b384ad690a3b056029702a91cbf1c7469953a18415