Retractable bollards are a type of security barrier that can be raised or lowered as needed to control vehicular or pedestrian access to a specific area. They are commonly used in high-security locations, such as government buildings, airports, and commercial areas, to prevent unauthorized vehicle access. Retractable bollards can be controlled manually or electronically, and some models can be operated remotely. They are typically made of durable materials such as steel or concrete and can withstand significant impact from a moving vehicle. In addition to their security benefits, retractable bollards can also help to regulate traffic flow and improve pedestrian safety in public areas.