Guidelines for the conversion of urban four-lane undivided roadways to three-lane two-way left-turn lane facilities

Details

• Creators:
  Knapp, Keith K. ; Giese, Karen
• Corporate Contributors:
  Iowa State University. Center for Transportation Research and Education ; Iowa. Dept. of Transportation
• Subject/TRT Terms:
  • Three lane highways
  • Four lane highways
  • Two way left turn lanes
  • Level of service
  • Arterial highways
  • Before and after studies
  • Alternatives analysis
  • Research
  • Traffic flow
  • Traffic volume
  More +
• Resource Type:
  Tech Report
• Geographical Coverage:
  Iowa
• Corporate Publisher:
  Iowa State University. Center for Transportation Research and Education
• Abstract:
  The primary objective of this research project was to develop a set of guidelines to assist in the selection of candidate roadways for urban four-lane undivided to three-lane cross section conversions. The authors evaluated and assessed the physical, operational, and safety characteristics that appear to be compatible with the consideration and/or feasibility of this type of conversion. These characteristics were evaluated qualitatively, with simulation software, and through an interpretation of subjective and objective before-and-after study results from four-lane undivided to three-lane conversions throughout the United States and Iowa. Some of the roadway characteristics investigated were roadway function and environment, overall traffic volume and level of service, turning volumes and patterns, weaving/speed/queues, crash types and patterns, pedestrian and bicycle activity, right-of-way availability/cost/acquisition, and several other general characteristics (e.g., parallel parking).
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/14499/dot_14499_DS1.pdf
• File Type:
  [PDF - 625.30 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:bd8da5a372a6a3ba04b982d09828e567bed8da01fe5ba3d0b6180059556c38d4