Boom barriers (or toll barrier gate) are equipped with multiple safety features to prevent accidents, protect vehicles, and ensure smooth operations. Here are the key safety mechanisms commonly found in barrier gates:  

1. Auto-Retraction Mechanism 

   - If the barrier arm detects an obstacle (like a vehicle or person) while closing, it automatically stops and reverses to avoid collision.  

   - Uses sensors (infrared, induction loops, or pressure sensors) to detect obstructions.  

2. Emergency Quick Release

   - Allows manual lifting of the barrier arm in case of power failure or emergencies.  

   - Often used by security personnel or toll operators.  

3. Safety Loops (Inductive Sensors)

   - Embedded in the road to detect vehicles stuck in the barrier’s path.  

   - Prevents the gate from closing if a vehicle is still present.  

4. Reflective Strips & LED Lights

   - High-visibility reflectors or LED warning lights on the barrier arm for nighttime visibility.  

   - Alerts drivers when the gate is lowering or rising.  

5. Speed Control & Slow Down Mechanism

   - The barrier arm moves at a controlled speed (not too fast) to minimize impact if a collision occurs.  

   - Some barriers have "soft-start and soft-stop" features for smoother operation.  

6. Breakaway Design 

   - If hit with significant force, the barrier arm detaches easily to minimize damage to the vehicle or gate mechanism.  

   - Commonly used in parking lots and low-speed zones.  

7. Anti-Crush Technology 

   - Advanced barriers use pressure-sensitive edges that stop immediately upon contact with an object.  

8. Fail-Safe Mechanism  

   - In case of power failure, some barriers default to the open position to avoid trapping vehicles.  

   - Others use battery backups to ensure continued operation.  

9. Alarm & Warning Systems

   - Audible alarms or voice alerts warn pedestrians and drivers when the barrier is moving.  

   - Flashing lights or beepers enhance safety in high-traffic areas.  

10. Remote Monitoring & Manual Override 

   - Toll operators can override the system in emergencies.  

   - CCTV cameras and sensors help monitor barrier operations.  

Applications:

These safety features are crucial in:  

- Toll plazas (to prevent accidents during payment)  

- Parking lots (to avoid vehicle damage)  

- Railway crossings (where barriers block trains)  

- Secure facilities (to control unauthorized entry)