Most streets that require traffic to be blocked for security reasons still provide access for certain approved vehicles. The bollards on the turntable are fixed, but as the table swivels, the orientation of the bollards changes enough to allow traffic to pass. When vehicle traffic is prohibited, however, the bollards do not block pedestrian access, a key feature for busy urban areas with high foot traffic.
The Turntable Vehicle Barrier (TVB) is certainly not the only such security barrier available; the most common options include operable bollards, steel plate barriers, and clamshells. But unlike these hydraulically powered barriers, the TVB uses a caster bearing system to turn.
The turntables have been in place in New York's financial district since last year, replacing clamshell barriers that limited pedestrian access and disrupted the view. Integrated light panels signal to drivers whether or not the street is passable. The perforated-bronze cladding mimics the finish of the existing sidewalk barriers.