THE EFFECTS OF THE TWO-WAY LEFT-TURN LANE ON ACCIDENTS IN THE SIX COUNTY AREA

This report summarizes the effect of a two-way left-turn lane (TWLTL) on affected accidents and total accident rates after installation on a given section of roadway in the six county area. Examination of these two measures will make it possible to determine the safety effectiveness of the TWLTL in reducing total accident rates and affected accident rates in the Chicago area. The evaluation methodology is described, and the findings are reported. Based on the limited number of 2-way left-turn lane segments available for this study, the overall effect of the TWLTL in the area seems positive. In four out of five segments analyzed, the accident rate dropped after the TWLTL was installed. In the remaining segment, the accident rate peaked during the first 18 months after the TWLTL installation, and dropped gradually to below the accident rate prior to its installation. Land use effects, and the effect of familiarity with the TWLTL use is also discussed.

• Corporate Authors:

  Chicago Area Transportation Study

  300 West Adams Street
  Chicago, IL  United States  60606
• Authors:
  • NICHOLAS, A C
• Publication Date: 1988

Media Info

• Features: Figures; Tables;
• Pagination: p. 1-8
• Serial:
  • Operations Review
  • Volume: 6
  • Issue Number: 1
  • Publisher: Chicago Area Transportation Study

Subject/Index Terms

• TRT Terms: Crash rates; Impact studies; Land use; Left turn lanes; Safety; Traffic crashes; Traffic safety; Two lane highways
• Uncontrolled Terms: Two way traffic
• Old TRIS Terms: Land use effects
• Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors; I73: Traffic Control;

Filing Info

• Accession Number: 00475570
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 31 1988 12:00AM