Passenger safety in public buses is a significant concern, particularly for standing individuals during sudden braking or acceleration. This study investigates a socially assistive robot conductor designed to promote seated behaviour and reduce driver burden by delivering real-time safety messages based on input from an AI-based passenger monitoring system. In a preliminary two-day field trial in Kawasaki City, Japan, both passengers and drivers responded positively, highlighting the robot’s clarity, politeness, and usefulness, while also noting issues with timing and message overlap with the driver. These early findings suggest that socially interactive robots, when designed with both operational awareness and human-centred adaptability, have the potential to improve onboard safety and support driver communication tasks.