 |
 |
|
|
|
Collision Type and Severity
Collisions can be of several types:
Collision severity is often characterized by parameters that can be helpful to the fire investigator. Frequently, an accident reconstructionist makes judgments about collision damage according to the seven-digit SAE Collision Deformation Classification [1]. This classification is used to characterize the location and extent of damage in an abbreviated format. Some examples of the coding for this classification include:
Direction of Force During Impact: The Principal Direction of Force (PDOF) is the direction from which impact force is applied to the vehicle. A clock face is assigned to the vehicle with 12:00 being at the front. Hence, a frontal collision into a wall would have an impact location of "Front" and a PDOF (on the subject vehicle) of 12:00. A sideswipe from an overtaking car on the driver’s side of the subject vehicle would have an impact location of "Left" but a PDOF of 6:00. In the SAE Collision Damage Classification system, the first two digits are the PDOF clock position.
Area of Deformation: The area of deformation broadly defines the area of the subject vehicle that was damaged. It is given a letter designation, such as “F” for front, or “U” for underside.
Other codes exist for
These factors, as well as measurements of crush damage and other vehicle data are analyzed by the accident reconstructionist to determine a measure for the severity of impact. This is often characterized by the “Delta V” or speed change of the vehicle as a result of impact. Delta V is used to standardize the assignment of impact severity by normalizing the result for the weight of both the vehicle, and the object with which it collides. It is typically calculated by analytical techniques, and sometimes confirmed by crash tests.
For statistical information relating fire location to collision type, click here.
References
|
|