Bollard
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A bollard is a short vertical post. Originally meaning a strong post used on a quay for mooring, the term is also used in the United Kingdom for a variety of structures to control or direct road traffic.
Mooring bollards
A bollard is a short wooden, iron or stone post used on a quayside for mooring ships. The term may be related to bole, meaning the lower trunk of a tree. Bollards are rarely totally cyclindrical, but typically have a larger diameter near the top to discourage mooring warps (docklines) from coming loose. The Mallaig example exaggerates this idea with a flattened overhanging top.
Road traffic control
Bollards are strong metal posts that can be used to close a road or path to vehicles above a certain width. Bollards can be mounted close enough to 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 emergency vehicles.
The American Heritage Dictionary describes this use of Bollard as "chiefly British", although the term has crept into the jargon of some American universities.
A recent development is the "rising bollard" - a bollard that can be lowered entirely below the road surface 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.
Road traffic direction
Bollards are frequently used to direct traffic around a traffic island.
The term "robotic bollards" has been applied to traffic barricades capable of moving themselves into position on a roadway. (See this [story from the BBC].)
Mountaineering
In mountaineering, a bollard is a large pile of snow or a block of ice shaped to form a secure anchor point. While such bollards can be quite strong, they are time consuming to build and not as commonly used as flukes, pickets, ice screws and Abalokov threads.
Other meanings
[The Bollard] is also an online alternative news publication in Portland, Maine.USCGC Bollard is a US Coast Guard cutter operating in Long Island Sound and north to Narragansett Bay.
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