Which security control best prevents tailgating into a restricted area?

Which security control best prevents tailgating into a restricted area?

• A. Security guard station
• B. Tailgate detector
• C. ID badge reader
• D. Man trap

Answer: (D)

Tailgating happens when someone gains access by following an authorized person through a secure door without a separate verification. The best defense is a mechanism that enforces one person at a time and requires independent authentication for each entrant. A man trap uses a small, controlled vestibule with two interlocking doors. A person must be authenticated to enter the first chamber and only then can the second door be opened for that person, ensuring the second person cannot slip through behind them. This setup prevents multiple people from entering on a single credential and provides a clear point to verify identity, while also often logging access attempts for auditing. Other options rely more on human behavior or looser checks. A security guard station depends on constant vigilance and can be bypassed if the guard is distracted. A tailgate detector might alert after the fact and doesn’t stop the entry. An ID badge reader on its own validates credentials but can still be abused if someone holds the door open for another. In contrast, a man trap mechanically enforces single-entry flow and per-person verification, making it the strongest choice for preventing tailgating into a restricted area.

Tailgating happens when someone gains access by following an authorized person through a secure door without a separate verification. The best defense is a mechanism that enforces one person at a time and requires independent authentication for each entrant. A man trap uses a small, controlled vestibule with two interlocking doors. A person must be authenticated to enter the first chamber and only then can the second door be opened for that person, ensuring the second person cannot slip through behind them. This setup prevents multiple people from entering on a single credential and provides a clear point to verify identity, while also often logging access attempts for auditing.

Other options rely more on human behavior or looser checks. A security guard station depends on constant vigilance and can be bypassed if the guard is distracted. A tailgate detector might alert after the fact and doesn’t stop the entry. An ID badge reader on its own validates credentials but can still be abused if someone holds the door open for another. In contrast, a man trap mechanically enforces single-entry flow and per-person verification, making it the strongest choice for preventing tailgating into a restricted area.