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.

These barriers consist of a long arm, or boom, that lowers and raises to control vehicle access. There are primarily two types of boom barriers: manual and automatic. Manual Boom Barriers require human intervention to operate, where a person must physically lift or lower the boom to control traffic.