🤖 AI Summary
Conventional vehicle-centric functional safety approaches fail to quantify autonomous vehicles’ (AVs) interactive impact on overall traffic flow, hindering large-scale deployment.
Method: This paper proposes a novel “behavioral safety” paradigm, establishing a third-party evaluation framework centered on AV–traffic environment interaction. It comprises two components: (1) a driver’s license test—assessing controlled-scenario responsiveness—and (2) a driving intelligence test—statistically analyzing safety-critical events in naturalistic traffic. Leveraging Autoware.Universe (L4), the framework integrates high-fidelity simulation with real-world testing at Mcity, employing scenario-driven evaluation, automated safety-event detection, and statistical modeling.
Contribution/Results: We formally define behavioral safety for the first time, extending beyond functional safety by quantifying AV-induced traffic perturbations. The AV passed 6 of 14 license-test scenarios; real-world testing yielded a collision rate of 3.01×10⁻³ per mile—approximately 1,000× higher than human drivers—and uncovered multiple previously unknown unsafe scenarios, validating the paradigm’s necessity and effectiveness.
📝 Abstract
Autonomous vehicles (AVs) have significantly advanced in real-world deployment in recent years, yet safety continues to be a critical barrier to widespread adoption. Traditional functional safety approaches, which primarily verify the reliability, robustness, and adequacy of AV hardware and software systems from a vehicle-centric perspective, do not sufficiently address the AV's broader interactions and behavioral impact on the surrounding traffic environment. To overcome this limitation, we propose a paradigm shift toward behavioral safety, a comprehensive approach focused on evaluating AV responses and interactions within the traffic environment. To systematically assess behavioral safety, we introduce a third-party AV safety assessment framework comprising two complementary evaluation components: the Driver Licensing Test and the Driving Intelligence Test. The Driver Licensing Test evaluates the AV's reactive behaviors under controlled scenarios, ensuring basic behavioral competency. In contrast, the Driving Intelligence Test assesses the AV's interactive behaviors within naturalistic traffic conditions, quantifying the frequency of safety-critical events to deliver statistically meaningful safety metrics before large-scale deployment. We validated our proposed framework using Autoware.Universe, an open-source Level 4 AV, tested both in simulated environments and on the physical test track at the University of Michigan's Mcity Testing Facility. The results indicate that Autoware.Universe passed 6 out of 14 scenarios and exhibited a crash rate of 3.01e-3 crashes per mile, approximately 1,000 times higher than the average human driver crash rate. During the tests, we also uncovered several unknown unsafe scenarios for Autoware.Universe. These findings underscore the necessity of behavioral safety evaluations for improving AV safety performance prior to widespread public deployment.