Martello Bollard

Inspired by the Martello Towers on England's coast, the bollard is designed to protect pedestrians and property just as its historic precedent once protected the coastline. Its slope shifts the momentum of a vehicle in the event of a collision, pushing it upwards so that it loses speed. The New York City Department of Transportation  has installed bollards on various meridians and sidewalks throughout the city. See also Access Control Bollard