Glossary

Acceleration Severity Index: The index is used as a measure for ascertaining the severity of impacts of vehicles against road equipment devices. It takes into account the decelerations of vehicles in the longitudinal, transverse, and vertical directions compared to maximum tolerable values.
Actions: Actions which may affect the compliance of the works with the essential requirements are brought about by agents acting on the works or parts of the works. Such agents include mechanical, chemical, biological, thermal and electro-magnetic agents.
Active fire protection measures: Systems and equipment installed to reduce danger to persons and property by either detecting fire, extinguishing fire, removing smoke and hot gases, or any combination of these functions.
Adjoining works: Construction works with common or connecting building elements (Opposite: separated works).
Alarm: Sudden attention or action for protection of persons or property (ISO 8201, 1987).

Boxed Value: The Boxed Value, used at the ENV stage together with the National Application Documents, offered a National choice for a value. It has to disappear in the EN Eurocodes.
Break-away safety: Passive safety of road equipment that ensures that the equipment readily disengages, fractures, or bends away from impacting vehicles.