A bollard is a short vertical post. Originally it meant a post used on a ship or a quay, principally for mooring. The word now also describes a variety of structures to control or direct road traffic, such as posts arranged in a line to obstruct the passage of motor vehicles.[1] In addition, bollards are used in the lighting industry to describe short, post-like light fixtures.
The term is probably related to bole, meaning a tree trunk.[2][3] The earliest citation given by the Oxford English Dictionary is from 1844: previously, simpler terms such as "post" appear to have been used. The Norman-French name Boulard (still often found in Normandy) may be related.
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The National Clearinghouse for Educational Facilities (NCEF), managed by the National Institute of Building Sciences (NIBS), cited three dozen applications of bollards.[4][5] The following list of open areas is encompassed by the ABA, NCEF and WBDG recommendations:
Listed below are the building design objectives and requirements under fire or security related instances on Campuses and their relationship to the use of bollards according to the Association of Higher Education Facilities.[6]
In the maritime contexts in which the term originates, a bollard is either a wooden or iron post found as a deck-fitting on a ship or boat, and used to secure ropes for towing, mooring and other purposes; or its counterpart, a short wooden, iron or stone post on a quayside to which craft can be moored. The Sailor's Word-Book of 1867 defines a bollard in a more specific context as "a thick piece of wood on the head of a whale-boat, round which the harpooner gives the line a turn, in order to veer it steadily, and check the animal's velocity".
Historically (in the 17th and 18th centuries) old cannon were often used as bollards on quaysides: they would be buried in the ground muzzle-first to approximately half or two-thirds of their length, leaving the breech (rear end) projecting above the ground for the attachment of ropes. Such cannon can still occasionally be found. Later (19th-century) bollards were often given the same cannon shape.
Mooring bollards are seldom exactly cylindrical, but typically have a larger diameter near the top to discourage mooring warps (docklines) from coming loose. Single bollards sometimes include a cross rod to allow the mooring to be bent into a figure eight.
Bollards are rigid posts that can be arranged in a line to close a road or path to vehicles above a certain width or to separate traffic from pedestrians.[7]
The American Heritage Dictionary describes this use of bollard as "chiefly British", although the term has crept into the jargon of some American universities where dense traffic necessitates the use of bollards for access control.
Bollards can be mounted near enough to each other that they block ordinary cars, for instance, but wide enough to permit special-purpose vehicles through. Bollards can be used to enclose car-free zones: Removable bollards allow access for service and emergency vehicles. Bollards and other street furniture are used to control overspill parking onto sidewalks and verges.[8]
Tall (1.15 meter/4 foot) slim (10 cm/4 inch) fluorescent red or orange plastic bollards with reflective tape and removable heavy rubber bases are frequently used in road traffic control where traffic cones would be inappropriate due to their width and ease of movement. Also referred to as delineators, the bases are usually made from recycled plastic, and can be easily glued to the road surface to resist movement following minor impacts from passing traffic. Sometimes called "T-top bollards" from the T-bar moulded into the top for tying tape, the bollard is an economical, cost effective, and safe delineation system designed especially for motorways and busy arterial roads. In conjunction with plastic tape, it is also effective in pedestrian control.
Bollards may be hinged at ground level, allowing them to be folded flat to permit vehicles to drive over them. In such cases they are generally fitted with padlocks at the base, to prevent their being lowered without proper authorisation.
Retractable or "rising" bollards can be lowered entirely below the road surface (generally using an electric or hydraulic mechanism) to enable traffic to pass, or raised to block traffic. Rising bollards are used to secure sensitive areas from attack, or to enforce traffic rules that are time related or restrict access to particular classes of traffic. They are increasingly common around the world to hinder vehicle-based terrorist actions from achieving close proximity to buildings, and are also used to prevent ram-raiding such as in the 2007 Glasgow International Airport attack. They are also useful in mixed-use public spaces, which support both pedestrian use and emergency and or service vehicle use. These bollards are usually priced between $11,000 to $100,000 depending on its ability to ram vehicles based on speed. The most expensive bollards can stop vehicles at speeds of about 50mph.
Manually retractable bollards (lowered by a key mechanism) are found useful in some cases since they do not require retrofitting into existing landscapes, or any electrical hookups or hydraulic systems.[9]
The term "robotic bollards" has been applied to traffic barricades capable of moving themselves into position on a roadway.[10]
Self-righting bollards can take a nudge from a vehicle and return to the upright position without causing damage to the bollard or vehicle. They are popular in car park buildings and other areas of high vehicle usage.
A bell bollard is a device that deflects vehicles' tires. The wheel mounts the lower part of the bollard and is deflected by its increasing slope. Such bollards are effective against heavy goods vehicles that can damage or destroy other types of street furniture.[11]
Internally illuminated traffic bollards (herein referred to as traffic bollard) have been in existence throughout the United Kingdom since the 1930s, although the term "bollard" only seems to have been in common use since the late 1940s. They are primarily used at modern roundabout intersections within the splitter islands (a raised or painted area on the approach of a modern roundabout used to separate entering from exiting traffic, deflect and slow entering traffic, and provide storage space for pedestrians crossing the road in two stages)[12] and at the ends of pedestrian refuge islands, typically located at mid-block pedestrian crosswalks. They are used to supplement street signs and street lighting to provide a visual cue to approaching drivers that an obstacle exists ahead during hours of darkness and during periods of low visibility:[13][14] (fog, rain, snow, haze, etc.) and that braking may be required.
A traffic bollard consists of three parts:[15]
Road agencies in the United States are beginning to experiment with modern traffic bollards. The first modern traffic bollard was installed at a modern roundabout intersection (State Road 89 and Willow Lake Road) in the City of Prescott, Arizona They were also used to prepare for the Republican Convention in New York City. (see middle thumbnail photo at right). The traffic bollards at this intersection are very similar to devices found throughout the United Kingdom with the following exceptions:
Traffic Calming
According to the Traffic Calming organization bollards can be used in two types of situations[17]:
Israel's Transportation Research Institute found that by putting bollards at highway exits to control traffic also reduced accidents.[18]
Bollards use to contribute to safety and security are extensive. The American Bar Association (ABA) state that bollards are used to contribute to homeland security.[19] Also the NIBS’s site—the Whole Building Design Guide (WBDG)—recommends in its Design Guidance that open spaces surrounding and contiguous to buildings be included as integral parts of a security design.[20] See Crime prevention through environmental design for more.
Security-related Bollard types
In the security industry physical site security bollards have assumed a prominent role, of which there are two main kinds:
According to the National Institute of Building Sciences, non-crash resistant bollards are “perceived impediments to access” and address the actions of two groups.
According to the International Fire Code (IFC-2009) and the National Fire Protection Association Fire Code 1 (NFPA-1) all new buildings or renovated buildings must have fire access roadways to accommodate fire apparatus and crews and other first responders. Thus the choice of bollard styles must apply to the NFPA’s Code 1710. Bollard are now designed in terms of how long it takes to remove or collapse them to allow first responders entry to the access roadway.[22]
Relevant Case Studies A case study from New York City on the subject was written in 2007[23]:
Bollards are used as a form of permanent utility location. They are sometimes placed next to warehouse and garage door edges to prevent large trucks from hitting the door jambs.
The term bollard light is a type of architectural outdoor lighting that is a short, upright ground-mounted unit typically used to provide cutoff type illumination for egress lighting, to light walkways, steps, or other pathways. These types of light fixtures typically give off light from the top or the sides.
In Australia, decorative bollards, designed and painted by Jan Mitchell, are placed in around the city of Geelong, Victoria, to enhance the landscape as a form of outdoor public sculpture. Usually they are made of timber, minimally modified from the traditionally cylindrical, wooden, maritime bollard shape, but brightly painted to resemble human figures. Such figures - which may be historical or contemporary, particular or generic - are sited singly or in clusters along the waterfront and in other areas where people gather. Decorative bollards have become a well-known feature of the city of Geelong and reflect its history as a major Australian port.[24]
In Antwerp, Belgium, artist Eddy Gabriel transformed a bollard to look like a toadstool in 1993. This example was followed massively, turning the quaiside of the river Schelde into a street art gallery [25]