  Automated vehicles (AVs) are of great potential in reducing crashes on the
road. However, it is still complicated to eliminate all the possible accidents,
especially those with vulnerable road users (VRUs), who are among the greater
risk than vehicle occupants in traffic accidents. Thus, in this paper, we
conducted a systematic review of safety-critical scenarios between AVs and
VRUs. We identified 39 papers in the literature and typical safety-critical
scenarios between AVs and VRUs. They were further divided into three
categories, including human factors, environmental factors, and vehicle
factors. We then discussed the development, challenges, and possible solutions
for each category. In order to further improve the safety of VRUs when
interacting with AVs, multiple stakeholders should work together to 1) improve
AI and sensor technologies and vehicle automation, 2) redesign the current
transportation infrastructure, 3) design effective communication technologies
and interfaces between vehicles and between vehicles and VRUs, and 4) design
effective simulation and testing methods to support and evaluate both
infrastructure and technologies.
