A research team from the Cognitive Neurotechnology Unit and the Visual Perception and Cognition Laboratory, Department of Computer Science and Engineering at Toyohashi University of Technology, investigated human behavior and comfort when handing over a package to an autonomous mobile delivery robot while walking—an interaction envisioned for logistics in future smart cities. The results showed that people tend to feel more comfortable when the robot approaches them more closely, whereas they tend to feel discomfort when the robot stays farther away. This tendency was particularly pronounced when the package being carried was heavy. On the other hand, when the robot came close, participants often slowed down their walking speed and sometimes stopped momentarily, exhibiting brief hesitation. These findings suggest that humans may perceive robots as “helpful partners” rather than mere machines, and that appropriate approach distances and motion designs are essential for achieving comfortable human–robot collaboration. The study was published online in the International Journal of Social Robotics on October 20, 2025.