B Automatic barrier systems are the simplest, yet effective automated barrier used today. Consisting of a long arm that lowers automatically to block the path of oncoming traffic. To raise the arm of the boom gate, the driver of the vehicle must present a pass, enter a code, pay a toll or wait for recognition before it is safe for them to proceed. Typically, an electric motor raises and lowers the arm, while a sensor or security access system controls the motor operation.

Boom gates can be also placed at a checkpoint and at the entrances of restricted areas. Normally, in these instances, the driver will have to provide identification, tap an access fob against a sensing plate or swipe an access card to enter. Boom barriers play a pivotal role in ensuring security where there is a high level of risk involved in the form of unauthorized entry because of a large flow of visitors.