A boom barrier goes by many names. Sometimes called a barrier arm, a boom, a boom gate, or an access barrier arm; these all mean the same thing. A boom barrier arm is a gate or access point that regulates traffic flow by means of a long arm that pivots on the opener. The arm is also called a boom. This might be familiar to anyone that has used a microphone before since this term is also used for the arm that holds a microphone. The opener or operator is the entire structure that moves the arm up and down. They come in many different shapes and sizes depending on the application and where they will be installed.



Barrier openers are typically used in access areas where traffic needs to be regulated. Areas such as parking garages, toll roads, car washes, private roads, railway crossings, and security checkpoints are where most boom barrier openers will be. The length of the arm is generally anywhere from 6' (1.8 m) all the way up to 33' (10 m). Applications that need longer booms are places that need large, wide lanes for buses and trucks, such as a business driveway or an airport. Parking garages may only need smaller-length barrier arms since only one vehicle should be passing at a time.


Barrier arms can be operated in a number of different ways. Some of them are still manually operated, or at least can still be if the power goes out. Most of the others, though, are automatic. This allows the user to conveniently use the gate without the need to get out of the vehicle. The gate automatically opens and closes via different sensors that tell the barrier arm what to do. Photo Eyes are the most common type of sensor that detects vehicles. They're also required in order to comply with the UL 325 Safety Standards. Loop Detectors are another very common sensor that access gates use. These are popular for traffic lights as well. They work by installing a wire just under the surface (usually concrete or asphalt) and connecting it to a loop detector. There is a small electrical current running through the wire, and when something changes the level of current in the wire, it is detected and will trigger whatever action is programmed. Loops work by induction rather than magnetization.