INFINITE SYSTEMS INSIGHTS:

 

Turnstile Tailgating Prevention: Sensors, Access Control and Secure Lobby Design

Turnstiles help regulate the movement of people into offices, commercial buildings and secured facilities. However, controlling the gate alone does not eliminate tailgating. Effective prevention combines passage-detection sensors, credential verification, physical lane design, CCTV monitoring and clear security procedures to identify and respond to unauthorized entry attempts.

---

01 / UNDERSTANDING THE SECURITY RISK

What Is Tailgating at a Turnstile?

Tailgating occurs when an additional person attempts to enter a controlled area using another person’s valid authorization. Instead of presenting an individual credential, the unauthorized person follows closely behind an authorized user through the same passage.

This can happen deliberately or accidentally, particularly in busy entrances where people are rushing, carrying items or entering in groups. Without appropriate detection and security procedures, the system may register a valid credential while allowing more than one person to pass.

Common situations that should be considered during system design include:

• Two people attempting to pass through one authorized opening.
• A person following closely behind an authorized user.
• Reverse movement through a controlled lane.
• A person attempting to enter before the gate has completed its previous passage cycle.
• Unauthorized entry through an adjacent door or an open area beside the turnstile.

The objective is to identify abnormal passage behavior while allowing legitimate users to move through the entrance efficiently.

---

02 / SENSOR-BASED DETECTION

Use Sensor-Based Passage Detection

Modern speed gates and selected optical turnstiles use multiple sensors along the passage to monitor movement. These sensors help the controller determine whether a person has entered, moved through or exited the lane in accordance with the expected passage sequence.

Depending on the model, sensor configuration and controller logic, the system may identify abnormal conditions such as multiple-person passage, unauthorized movement or reverse entry.

Important sensor and configuration considerations

Sensor-based detection should be evaluated using the manufacturer’s supported specifications. Not all turnstiles offer the same detection capabilities, and performance may vary with passage geometry, user behavior and installation conditions.

---

03 / CREDENTIAL VERIFICATION

Coordinate Credential Authorization Before Passage

The access-control reader should be positioned where users can present an approved credential before entering the controlled lane. Depending on the selected system, credentials may include RFID cards, mobile credentials, PINs, biometric verification or other supported identification methods.

The turnstile controller and access-control platform should coordinate the authorization signal with the gate’s operating sequence. One valid authorization should permit only the intended passage, subject to the gate’s supported operating logic.

Access-control design considerations

• Position the reader before the controlled passage, with clear visibility and convenient reach.
• Configure access permissions according to the organization’s security policy.
• Verify the communication and control interface between the access-control system and turnstile.
• Define how repeated credential presentation is handled.
• Confirm how denied access, timeout and abnormal passage events are reported.
• Test both normal authorization and unauthorized entry scenarios.

Credential verification and passage detection serve different purposes. A valid credential confirms that a user has permission to enter, while passage sensors help determine whether the physical movement through the gate follows the expected sequence.

---

04 / LOBBY AND PHYSICAL LAYOUT

Design the Lobby Around the Turnstile Line

A properly configured turnstile can still be bypassed if the surrounding lobby has open gaps, uncontrolled side corridors or adjacent doors that allow people to enter without authorization.

The physical layout should guide visitors and employees through the intended access-control point. Coordinate the turnstile arrangement with reception counters, walls, partitions, doors and other access routes.

Physical barriers should be coordinated with the overall building layout and applicable fire and life-safety requirements. Emergency egress must remain available in accordance with the approved building design and relevant regulations.

---

05 / ACCESSIBILITY AND VISITOR MOVEMENT

Provide an Accessible Lane Without Creating a Security Bypass

Some facilities require a wider passage for wheelchair users, visitors with mobility needs, deliveries or other authorized movement. This route should be included in the security design rather than treated as an uncontrolled opening beside the turnstile line.

Where required, provide an appropriately sized accessible passage with suitable access-control arrangements and monitoring. Depending on the project requirements, this may use a wider speed gate, a controlled swing gate or another approved accessible entrance arrangement.

Consider the following:

• Provide adequate clear passage width for the intended users.
• Coordinate the reader location and authorization method with the accessible route.
• Define whether the lane is monitored, supervised or operated by security personnel.
• Confirm that the selected gate supports the required safety and emergency-release functions.
• Maintain compliant emergency access and egress arrangements.

The objective is to provide an inclusive entrance while maintaining consistent access-control and security procedures across the facility.

---

06 / ALARM AND SECURITY RESPONSE

Configure Alarms and Define the Security Response

Tailgating detection is useful only when the event produces an appropriate response. Depending on the turnstile and access-control platform, abnormal passage activity may generate a local audible or visual indication, a controller event, a security workstation notification or an integrated CCTV event.

Before implementation, define which events should be reported and who is responsible for responding.

Examples of security events

• Multiple-person or suspected tailgating detection.
• Unauthorized or reverse-direction movement.
• Forced gate opening or abnormal gate status, where supported.
• Passage timeout or incomplete passage.
• Repeated access-denied attempts.

Security procedures should identify how guards or reception personnel verify an event, approach the situation and document incidents. Alarm thresholds and response actions should be configured to balance security with normal user movement.

---

07 / VIDEO VERIFICATION

Integrate CCTV for Monitoring and Incident Investigation

CCTV can support turnstile security by providing visual information about the entrance, helping operators verify alarms and investigate repeated unauthorized passage attempts.

Camera placement should cover the relevant approach and passage areas while providing useful views of user movement. The selected camera position, lens and mounting height should be based on the lobby layout and required level of identification or observation.

Camera integration should follow the site’s privacy, recording, access-permission and data-retention policies. Avoid unnecessary monitoring of areas unrelated to the security objective.

---

08 / COMMISSIONING AND TESTING

Test Real Passage Scenarios Before Handover

Commissioning should verify that the turnstile, reader, controller, sensors and monitoring functions operate together as intended. Testing should reflect the actual entrance layout and expected user behavior rather than relying only on a basic card-access demonstration.

Recommended test scenarios

1. Normal authorized passage: Verify that one valid credential permits the intended user to pass.
2. Unauthorized access: Confirm that invalid or unrecognized credentials do not grant passage.
3. Closely spaced users: Test the selected gate’s supported detection behavior when people move close together.
4. Reverse movement: Verify how the system handles movement against the authorized direction.
5. Hesitation and incomplete passage: Check the response when a user enters but does not complete the passage.
6. Items and luggage: Evaluate representative user behavior involving bags or carried items, within the manufacturer’s recommended test procedure.
7. Alarm reporting: Confirm that relevant events are displayed or reported through the configured monitoring platform.
8. Emergency operation: Verify safety functions, emergency release and approved egress behavior.

Use manufacturer-supported settings when adjusting sensor sensitivity and passage logic. Do not disable important detection functions simply because alarms appear inconvenient. Investigate the cause of unwanted alarms and adjust the configuration within the equipment’s supported operating limits.

---

09 / PROJECT PLANNING

Turnstile Tailgating Prevention Checklist

Use this checklist when evaluating an existing entrance or preparing a new turnstile access-control installation.

For project procurement, the scope should also identify gate quantities, lane dimensions, reader and controller requirements, integration interfaces, CCTV coverage, installation works, testing and commissioning activities, and any site-specific civil or electrical requirements.

---

10 / RELATED SOLUTIONS

Related Infinite Systems Solutions

Effective entrance security combines controlled pedestrian access, credential management and visual monitoring. Explore related solutions for an integrated facility security design.

---

11 / FREQUENTLY ASKED QUESTIONS

Frequently Asked Questions About Turnstile Tailgating Prevention

Can speed gates detect two people using one credential?

Many modern speed gates use multiple sensors and passage logic to identify abnormal or closely spaced movement. However, detection capabilities depend on the selected model, sensor arrangement, lane configuration and operating settings.

Does a wider lane increase tailgating risk?

Lane width affects passage geometry and sensor coverage. A wider passage should use equipment specifically designed and configured for that width and intended application. The overall security arrangement should also consider the types of users and items passing through the lane.

Where should the card reader be installed?

The reader should be positioned where an authorized user can present a credential before entering the controlled lane. Its location should be coordinated with the gate controller, direction of travel and user approach.

Should CCTV cover the turnstiles?

CCTV can support alarm verification and incident investigation when cameras provide suitable views of the entrance and passage areas. Camera selection and positioning should reflect the site’s monitoring objectives and privacy requirements.

Can reception prevent people from bypassing the turnstiles?

Reception layout can help guide visitors through the controlled entrance. However, it should be coordinated with walls, partitions, adjacent doors and other access routes to prevent uncontrolled gaps.

Should tailgating alarms be tested during commissioning?

Yes. Test representative passage scenarios, including closely spaced users and reverse movement where supported. Verify the alarm response, monitoring notifications and security procedures before the system is handed over.

Can a turnstile completely prevent tailgating?

No single gate should be treated as a complete solution against every unauthorized-entry scenario. Effective prevention requires suitable equipment, correct configuration, coordinated physical barriers, monitoring and trained security personnel.