What is one primary feature of scissor stairways?

Scissor stairways are defined by the unique configuration of having two stairways that share the same vertical shaft but run in opposite directions. This design is specifically advantageous for providing quick egress routes for occupants and efficient access for firefighters during emergencies. The two stairways function independently, allowing for simultaneous use by occupants and first responders, which helps to reduce congestion and improve overall safety during evacuations. This is crucial in high-rise buildings where stairwell traffic can become a significant issue during an emergency. The efficiency of this design plays a vital role in enhancing building safety protocols and is a consideration in modern architectural design for structures requiring multiple egress points.