The Problem Of Tailgating:
One of the biggest weaknesses of automated access control systems is the fact that most systems cannot actually control how many people enter the building when an access card is presented. Most systems allow you to control which card works at which door, but once an employee opens the door, any number of people can follow behind the employee and enter into the building. Similarly, when an employee exits the building, it is very easy for a person to grab the door and enter the building as the employee is leaving.
Anti-tailgating access control refers to restricting an unauthorized person from gaining access through a turnstile or gate after an authorized person has already gained access. Tailgating, also referred to as “piggybacking”, is a major security concern, making anti-tailgating turnstile systems necessary for many applications.