These bright yellow, typically rectangular objects are traffic control devices deployed to prevent vehicles from entering restricted areas. An example of their usage is at the entrance of pedestrian zones or cycle paths, physically stopping unauthorized vehicular access. The construction material is frequently a durable plastic or rubber composite, often hollow to allow for ballasting with water or sand for increased stability.
The benefit of these barriers is enhanced safety for pedestrians and cyclists by clearly delineating safe zones free from vehicle traffic. They also contribute to traffic calming measures in residential areas. Historically, simpler barriers like bollards or chains were used; however, these modern implementations offer improved visibility and are easily repositionable, making them adaptable to changing needs and temporary events.