Traffic barriers (sometimes called
crash barriers, or
Armco barriers, also known in North America as
guardrails or
guard rails and in Britain as
crash barriers) keep
vehicles within their
roadway and prevent vehicles from colliding with dangerous
obstacles such as boulders, buildings, walls or large
storm drains. Traffic barriers are also installed at the road side to prevent errant vehicles from traversing steep (non-recoverable) slopes or entering deep water. Traffic barriers are installed within
medians of divided highways to prevent errant vehicles from entering the opposing
carriageway of traffic and help to reduce
head-on collisions. Some of these barriers, designed to be struck from either side, are called median barriers. Crash barriers can also be used to protect vulnerable areas like school yards,
pedestrian zones or fuel tanks from errant vehicles.