Safety Effectiveness of Offsetting Opposing Left‐Turn Lanes: A Case Study

This paper discusses the benefits to intersection safety of offsetting left-turn lanes by widening the width of the lane-line marking between the left-turn lanes and their adjacent through lanes. The analysis was performed using an empirical Baye's procedure in order to account for potential bias due to regression-to-the-mean. Results from the analysis of 12 treated intersection approaches and 36 non-treated approaches in Lincoln, Nebraska, suggest statistically significant improvements in safety at the treated intersections.

[1]  S. Washington,et al.  Statistical and Econometric Methods for Transportation Data Analysis , 2010 .

[2]  D F Jarrett,et al.  Accidents at blackspots: Estimating the effectiveness of remedial treatment with special reference to the 'Regression-to-Mean' effect , 1981 .

[3]  E. Haver.  SELECTION FOR TREATMENT AS A SOURCE OF BIAS IN BEFORE-AND-AFTER STUDIES , 1980 .

[4]  Tarek Sayed,et al.  Safety Evaluation of Alternative Signal Head Design , 1998 .

[5]  Bhagwant Persaud,et al.  COMMON BIAS IN BEFORE-AND-AFTER ACCIDENT COMPARISONS AND ITS ELIMINATION , 1983 .

[6]  Lily Elefteriadou,et al.  Safety Effectiveness of Intersection Left- and Right-Turn Lanes , 2003 .

[7]  Patrick T McCoy,et al.  GUIDELINES FOR OFFSETTING OPPOSING LEFT-TURN LANES ON FOUR-LANE DIVIDED ROADWAYS , 1992 .

[8]  Neil Salkind,et al.  Using SPSS for Windows: Analyzing and Understanding Data with Disk , 1997 .

[9]  Patrick T McCoy,et al.  SAFETY IMPROVEMENTS AT INTERSECTIONS ON RURAL EXPRESSWAYS: A SURVEY OF STATE DEPARTMENTS OF TRANSPORTATION , 1993 .

[10]  Ezra Hauer,et al.  OBSERVATIONAL BEFORE-AFTER STUDIES IN ROAD SAFETY -- ESTIMATING THE EFFECT OF HIGHWAY AND TRAFFIC ENGINEERING MEASURES ON ROAD SAFETY , 1997 .

[11]  Bhagwant Persaud,et al.  Safety Effect of Roundabout Conversions in the United States: Empirical Bayes Observational Before-After Study , 2001 .

[12]  Ezra Hauer,et al.  Reflections on methods of statistical inference in research on the effect of safety countermeasures , 1983 .

[13]  Bryon Li.  INTERSECTION COLLISION AVOIDANCE - ITS DECISION REPORT , 2000 .

[14]  Patrick T McCoy,et al.  BENEFIT-COST EVALUATION OF LEFT-TURN LANES ON UNCONTROLLED APPROACHES OF RURAL INTERSECTIONS (ABRIDGMENT) , 1985 .

[15]  Anthony A Saka,et al.  MITIGATION OF SIGHT-DISTANCE PROBLEM FOR UNPROTECTED LEFT-TURNING TRAFFIC AT INTERSECTIONS , 1992 .