Accident Terms and Definitions

Blood alcohol testing
At all levels of blood alcohol concentration, the risk of being involved in a crash is greater for young people than it is for older people (Mayhew 1986). In 2001, 25% of drivers ages 15 to 20 who died in motor vehicle crashes had been drinking alcohol (NHTSA 2002b).

Reaction Time
The motorist who is not alert cannot cope with a sudden emergency as quickly as is necessary. An overly relaxed driver requires more time to react to an emergency than does an alert one.

Impaired Driving
Can be alcohol or any oher substance that changes judgement while driving. Impaired driving will affect one in three Americans during their lifetimes (NHTSA 2001a).

Linear Momentum
A quantity associated with the motion of an object along a straight path. The linear momentum of an object is defined to be equal to its mass times its velocity.

Failure to yield the right of way
Can be when you proceed forward while disregarding right of way signs or signals for other cars. You may not be the car that is sopossed to go forward.

Subpoena
Document issued by the authority of the court to compel a witness to appear and give testimony or produce documentary evidence in a proceeding. Failure to appear or produce is punishable by contempt of court.

Adjudication
A judgment or decree Adversary system - Basic U.S. trial system in which each of the opposing parties has opportunity to state his viewpoints before the court. Plaintiff argues for defendant's guilt (criminal) or liability (civil). Defense argues for defendant's innocence (criminal) or against liability civil).

Reference Point
In angular momentum, the point in space around which the motion of an object is described. The angular momentum of an object is defined in relation to some point, the reference point. The velocity and radius of an object are measured from the reference point.

Disregarding traffic controls
Can be going through a red light or stopping at a green light, diregarding special signals in traffic.

Breakover Angle
when a vehicle crests a hill, it's the angle at which the front tires still remain on the ground as the rear wheels continue to climb (see High Centered)