Evaluating the Operational Impact of Left-Turn Exclusive Number of Lanes: A Case Study from Qatar
Abstract
Left-turning movements can significantly reduce the overall capacity of signalized
intersections due to the queueing built up. Intersections with heavy left-turning volumes
tend to use multiple lanes to accommodate left-turn movements, such as double and
triple left-turn lanes. This study compares the potential impact of different left-turn
configurations for saturated/near saturated levels. A signalized intersection located in the
city of Doha, Qatar, is selected to be examined and evaluated. A microscopic simulation
approach is used to replicate the existing conditions before implementing different
traffic demands, left-turn bay configurations, and traffic control parameters. The results
suggest that signalized intersections, in general, and left-turn movements, in particular,
benefit from multiple left-turn lanes. However, the anticipated operational benefits vary
depending on several factors, such as the demand for left-turn movements and the length
of the left-turn bay. The findings obtained from this study could be helpful for planners
and decision-makers to decide the type of left-turn lane treatment needed to increase the
capacity for different conditions. This work can be extended to mathematically quantify
the expected operational improvements at signalized intersections
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- Civil and Environmental Engineering [851 items ]
- Theme 2: Materials and Transportation Engineering [43 items ]
- Traffic Safety [163 items ]