Ensuring robust wireless communication is paramount for the safety operations of connected and automated vehicles (CAVs). However, the susceptibility of these links to failure from hardware issues or the communication environment presents substantial safety challenges. Existing literature thoroughly examines temporary communication losses for single CAV or platoons, but overlooks the persistent failures confined to specific regions. To address this knowledge gap, our research assesses the safety repercussions of localized, persistent communication failures in a connected-vehicle-only setting. We developed a simulation incorporating detailed CAV driving dynamics, such as car following, lane changing, collision alerts, and driver intervention mechanisms. This study focuses on three distinct communication failure patterns, including random errors, random delays, and periodic data loss, within a designated zone of a two-lane highway. We found that the safety outcomes are uniquely sensitive to the disturbance factor, severity, and spatial coverage. The results provide a foundation for creating countermeasures against regional communication disruptions and enhancing the longitudinal safety mechanisms of CAVs.