Capacity of Right-Turn Lane Affected by Bicycles during Red Phase

During the red phase, the waiting cyclists beyond the stop line produce a new conflict with vehicles at an intersection, severely affecting right-turn vehicular traffic. This is addressed in traffic capacity estimation. Therefore, a model is developed to estimate right-turn lane capacity with the influence of bicycles during the red phase. First, a new conflict zone between waiting bicycles and right-turn vehicles is introduced and defined. The impact of bicycles entering conflict zones on right-turn vehicles is described by researching the correlation between vehicle velocity and bicycle volumes. Using various theories, a model for right-turn lane capacity is established. The proposed model is compared with the HCM model and the method of overlooking waiting bicycles. The results illustrate that the proposed model cannot only effectively estimate the capacity of the right-turn lane with the influence of bicycles during the red phase at the intersection but also quantitatively reflect the impact of bicycle volume on capacity.