Simulation Study Revealed That Crash Frequency was Reduced by Up to 88.43 Percent or 93.92 Percent Across Two Scenarios with the Introduction of an Automatic Emergency Braking System.
German Simulation Study Evaluated the Safety Impact of Sensor-Integrated Automatic Emergency Braking Systems at Urban Intersections.
Dresden
Predicting the impact on road safety of an intersection AEB at urban intersections. Using a novel virtual test field for the assessment of conflict prevention between cyclists/pedelecs and cars
Summary Information
Highly Automated Driving (HAD) systems and Advanced Driver Assistance Systems (ADAS) can improve road safety, comfort, and traffic efficiency. However, these systems face major challenges due to the complex, heterogeneous nature of urban traffic. This study simulated a high-risk conflict situation and employed a driver behavior model called DReaM (Driver Reaction Model). This allowed the researchers to investigate the safety impact of an intersection-specific Automatic Emergency Braking (AEB) system designed to detect cyclists. By simulating scenarios with varying sensor configurations, the study aimed to predict how effectively the AEB system could reduce crash frequency and collision severity at urban intersections.
METHODOLOGY
The study evaluated two high-risk scenarios at a unsignalized intersection: (1) a cyclist suddenly appearing from the left, behind visual obstructions while the car proceeds straight, and (2) a cyclist emerging from the driver’s blind spot and crossing ahead as the vehicle turns right. The simulation model was built using an open-source framework, which served as a virtual test field for baseline (no AEB) and prognosis (with AEB) conditions. Central to the simulation was DReaM, a cognitive driver behavior system that incorporated gaze behavior, reaction times, acceleration and deceleration limits, and stochastic variability. To ensure the simulation’s validity, real-world vehicle and cyclist trajectory, speed, and acceleration profile data were collected at an unregulated four-way urban intersection in Dresden, Germany, using drone observations over multiple days in November 2019.
FINDINGS
- When assessing the simulation for cyclists crossing from the left side with an AEB system with a sensor opening angle of 100 degrees, 99.28 percent of the simulation runs finished without a collision, representing a decrease in collisions by 86.98 percent.
- For the same scenario with a sensor opening angle of 180 and 210 degrees, 99.36 percent of the simulation runs were completed without a collision, indicating a reduction in crash frequency by 88.43 percent from the baseline scenario.
- When assessing the simulated scenario of turning right with a crossing cyclist, the 100-degree sensor setup led to a 58.35 percent reduction in crashes, while the 180 and 210-degree settings led to a 93.22 and 93.92 percent crash frequency decrease, respectively.
