Barrier

A barrier or barricade is a physical structure which blocks or impedes something.

Barrier may also refer to:

Physical

Automatic full barriers, which serve to block roads at railway crossings
Boom barrier, which serves to block vehicular access
Fitch Barrier, a plastic barrel filled with sand or water, used on highways as an impact attenuator
Roadblock, a temporary installation to control or block traffic on a road
Traffic barrier (crash barrier), used to keep vehicles within their roadway
- Cable barrier
- Concrete step barrier
- Constant slope barrier
- F-Shape barrier
- Guard rail
- Jersey barrier or K-rail, a type of concrete barrier used to divide highway traffic

Crowd control barrier, temporary fencing used to keep crowds inside or away from a certain area
Noise barrier, walls and other structures used to attenuate noise pollution

Thames Barrier, a flood control structure on the River Thames in England
Hesco bastion, a dirt-filled wire mesh/cloth container used for flood control and military fortification
Breakwater (structure), a barrier created as part of coastal defense or to protect an anchorage from the effects of both weather and longshore drift
Vapor barrier, any material used to resist diffusion of moisture through walls, ceilings or floors

Barrier isolator, a physical barrier between a laboratory technician and a work process
Blood–brain barrier, a separation of circulating blood and the brain extracellular fluid
Barrier (computer science), a type of synchronization in parallel computing
- Memory barrier, an instruction to enforce an ordering constraint on memory operations in a computer program
Potential barrier, a standard problem in physics of quantum mechanics
Sound barrier, the point at which an aircraft moves from transonic to supersonic speed

Barrier, Kentucky, a community in the United States
Barrier, Voerendaal, a place in the municipality of Voerendaal, in southeastern Netherlands
The Barrier, a lava dam in southwestern British Columbia, Canada
The Barrier, Great Ice Barrier, Victoria Barrier etc., later 19th–early 20th century names for the Ross Ice Shelf, Antarctica
Barrier Bay, an open bay in Antarctica
Barrier reef, a type of coral reef running along a coast for a long distance, e.g.:
- Belize Barrier Reef, a series of coral reefs straddling the coast of Belize
- Great Barrier Reef, in the Coral Sea off the coast of Queensland in north-east Australia
Barrier Volcano, an active shield volcano in Kenya
Gilf Kebir, Arabic for "the Great Barrier" in Egypt
Great Barrier Island, in the north of New Zealand
A misspelling of Barriere, British Columbia, a small community in Thompson-Nicola Regional District, British Columbia, Canada