Which of the following is NOT a type of safety device on escalators?

The emergency stop button is actually a critical component of escalator safety systems, allowing users to halt the escalator in emergencies. In contrast, the other options listed (automatic stopping device, sprinkler-vent method, and rolling shutter method) represent different types of safety or functional mechanisms utilized in escalators, while the emergency stop button is designed specifically for user intervention.

The automatic stopping device ensures that the escalator halts under certain hazardous conditions, while the sprinkler-vent method and rolling shutter method pertain more to fire safety and environmental concerns rather than the direct operation and immediate user safety of the escalator. Thus, by understanding the roles of these components, one can clearly see why the emergency stop button is a legitimate safety feature on escalators and is not anomalous in the context of escalator safety devices.