The Role of Integrity Monitoring in Connected and Automated Vehicles: Current State of Practice and Future Directions

Positioning integrity refers to the trust in the performance of a navigation system. Accurate and reliable position information is needed to meet the requirements of connected and automated vehicle applications, particularly in safety-critical scenarios. Receiver autonomous integrity monitoring (IM) and its variants have been widely studied for global navigation satellite system-based vehicle positioning, often fused with kinematic (e.g., odometry) and perception sensors (e.g., cameras). However, IM for cooperative positioning solutions that leverage vehicle-to-everything (V2X) communication has received comparatively limited attention. This article reviews existing research in the field of positioning IM and identifies various research gaps. Particular attention has been placed on identifying research that highlights cooperative-IM methods. It also examines key automotive safety standards and public V2X datasets to map current research priorities and uncover critical gaps. Finally, the article outlines promising future directions, highlighting research topics aimed at advancing and benchmarking positioning integrity.