An innovative design for left turn bicycles at continuous flow intersections

To improve the practical capacity of the continuous flow intersections (CFI) and eliminate the conflict between left-turn bicycles and through vehicles, an optimization design method for left-turn bicycles was proposed. The pre-stop line for through vehicles and the crossing passage for left-turn bicycles were set at the pre-signal points of the CFI. The control of the through vehicles at pre-signal was added in the proposed method. A linear programming model was established to achieve the maximum vehicular practical capacity. The optimization effectiveness and applicability for this design were validated by a case study and sensitivity analyses. The results show that the improvements in practical capacity obtained by the proposed method increase with the increase of the left-turn bicycles volume and through vehicle percentage, while decrease with longer cycle length. As for bicycles, the proposed method can reduce the delay in the case of high traffic demand.