This paper presents a case study regarding the effectiveness of dual lefts turning into short receiving lanes. It also provides a review of guidelines pertaining to the length of receiving lanes prescribed by many jurisdictions, which are generally associated with through movements at signalized intersections. This paper provides evidence from one case study that shows the same principles outlined for receiving lanes associated with through movements may not always need to be applied for left-turn situations; instead, left-turn lane/receiving lane configurations should be evaluated on a case-by-case basis. The specific case study focuses on the performance of dual lefts turning into 100-foot receiving lanes merging to one lane with a taper length of approximately 150 feet. The common perception, as well as much of the past research, would suggest that the design in question would result in very unbalanced lane utilization. However, the design resulted in virtually equal lane utilization. While the case study was by no means a scientifically rigorous evaluation and only represents one location, the authors believe that it provides insights regarding the geometry of the merge and travel patterns within the study area. These are likely to be important factors in assessing lane utilization for the dual left-turns. Since lane utilization factors significantly affect capacity estimates at signalized intersections, they are one of the most important inputs to an operational analysis of signalized intersections. It is hoped that the case study results will spur further research on this topic.
Samenvatting