Which measurement marks the threshold for classifying turnstiles as revolving doors?

Which measurement marks the threshold for classifying turnstiles as revolving doors?

• A. 31 inches
• B. 35 inches
• C. 39 inches
• D. 42 inches

Answer: (C)

Opening width is what codes use to classify devices as revolving doors. When the passage through the device is wide enough for a person to pass while the mechanism rotates around a central axis, it’s treated as a revolving door for egress and accessibility purposes. The threshold is 39 inches, because that width provides enough clearance for the rotating section to operate safely and for single-file passage. If the opening is narrower than 39 inches, it’s typically not considered a revolving door and is treated more like a standard turnstile or barrier. A width exceeding 39 inches is simply the boundary used to differentiate revolving-door configurations from smaller barriers, making 39 inches the decisive measurement.

Opening width is what codes use to classify devices as revolving doors. When the passage through the device is wide enough for a person to pass while the mechanism rotates around a central axis, it’s treated as a revolving door for egress and accessibility purposes. The threshold is 39 inches, because that width provides enough clearance for the rotating section to operate safely and for single-file passage. If the opening is narrower than 39 inches, it’s typically not considered a revolving door and is treated more like a standard turnstile or barrier. A width exceeding 39 inches is simply the boundary used to differentiate revolving-door configurations from smaller barriers, making 39 inches the decisive measurement.