This type of access control system is characterized by its reliance on human power to operate a pivoting arm that restricts or allows passage. Such a device is commonly found where pedestrian or vehicular traffic needs to be managed without automated mechanisms. A simple example includes an entrance to a park requiring a park ranger to physically open and close the arm.
These systems offer advantages such as low initial cost and minimal maintenance requirements, particularly in locations lacking reliable power infrastructure. Historically, they have been employed in areas where a physical presence is desired for monitoring or security purposes, predating the widespread adoption of automated systems. Their enduring presence signifies a simple, reliable, and controllable method of managing access.