  We present a practical verification method for safety analysis of the
autonomous driving system (ADS). The main idea is to build a surrogate model
that quantitatively depicts the behaviour of an ADS in the specified traffic
scenario. The safety properties proved in the resulting surrogate model apply
to the original ADS with a probabilistic guarantee. Furthermore, we explore the
safe and the unsafe parameter space of the traffic scenario for driving
hazards. We demonstrate the utility of the proposed approach by evaluating
safety properties on the state-of-the-art ADS in literature, with a variety of
simulated traffic scenarios.
