The second impact, also known as second collision and human collision, is the impact suffered between a vehicle occupant and the vehicle during a collision. The first impact is the impact between the vehicle and another object. There is also a third impact between the internal organs and the frame of the body.
The term was coined in the 1950s by Sergeant Elmer Paul of the
Indiana State Police
The Indiana State Police is the statewide law enforcement agency for the U.S. state of Indiana. Indiana was the 12th state to offer protection to its citizens with a State police (United States), state police force.
Its headquarters are in the ...
. Paul convinced Indiana authorities to investigate the mechanics of highway injuries, and worked with safety pioneer
Hugh DeHaven
Hugh DeHaven (3 March 1895 – 13 February 1980) was an American pilot, engineer and passive safety pioneer. DeHaven survived a plane crash while training as a Royal Canadian Flying Corps pilot during the First World War, and became interested in ...
.
The effects of the second impact are reduced by the use of
seat belt
A seat belt, also known as a safety belt or spelled seatbelt, is a vehicle safety device designed to secure the driver or a passenger of a vehicle against harmful movement that may result during a collision or a sudden stop. A seat belt reduce ...
s,
airbag
An airbag is a vehicle occupant-restraint system using a bag designed to inflate in milliseconds during a collision and then deflate afterwards. It consists of an airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. ...
s, interior vehicle padding and removing of aggressive structures.
''A HALF CENTURY OF ATTEMPTS TO RE-SOLVE VEHICLE OCCUPANT SAFETY: UNDERSTANDING SEATBELT AND AIRBAG TECHNOLOGY'' PDF
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References
Automotive safety
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