Safety assessment of queue jump lanes at signalized intersections: a conflict analysis study under heterogeneous traffic conditions

Evaluating the safety of Queue Jump Lanes (QJLs) is crucial in heterogeneous traffic conditions, especially in developing countries. This study assesses the safety performance of two QJL Design Configurations (DCs): DC1 (standard QJL) and DC2 (QJL with a presignal and bus advance area) across eight signalised intersections in India. Traffic microsimulation in VISSIM and conflict analysis in Surrogate Safety Assessment Model (SSAM) were used. A two-stage calibration procedure has optimised simulation parameters using ANOVA, Genetic Algorithm, and Kolmogorov–Smirnov test. Compared to the Base Scenario (BS), DC1 resulted in a 13.33% increase in rear-end conflicts and a 25.49% increase in lane change conflicts, whereas DC2 reduced these conflicts by 40.57% and 27.33%, respectively. The methodology achieved high consistency, with R² values of 0.921 for rear-end and 0.942 for lane change conflicts. The study underscores the need for safety integration in infrastructure planning and provides a transferable framework for evaluating QJL safety.