1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
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4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SURFACE VEHICLE RECOMMENDED PRACTICE J1674 AUG2009 Issued 1998-06 Revised 2009-08 Superseding J1674 JUN1998 Early Acquisition and Preservation of Information in a Motor Vehicle Crash RATIONALE This document has been
5、revised with editorial changes and to include additional technical information. The term “accident” has been replaced with the term “crash” in all instances including the title. 1. SCOPE The purpose of this SAE Recommended Practice is to offer simplified and prioritized guidelines for collecting and
6、 preserving on-scene data related to motor vehicle crashes. It is intended that these guidelines improve the effectiveness of data collection, which will assist subsequent analysis and reconstruction of a particular crash. This document is intended to guide early data collectors whose objectives inc
7、lude documenting information related to the crash. It may be used by law enforcement personnel, safety officials, insurance adjusters and other interested parties. This document identifies categories of scene physical features that deteriorate relatively quickly and recommends documentation task pri
8、orities. Detailed methods of collecting data are not part of this document. However, some widely used methods are described in the references in Section 2. 2. REFERENCES 2.1 Applicable Publications The following publications form a part of this specification to the extent specified herein. 1. Baker,
9、 J. S. and Fricke, L. B., “Traffic Accident Investigation Manual,” 9th Edition, Northwestern University Traffic Institute, 1986 2. Tumbas, N. S., Gilberg, A. N. and Fricke, L. B., “Minimum Guidelines for Efficiently Acquiring or Preserving Basic Information in a Motor Vehicle Accident,” SAE 880067 3
10、. Rivers, R. W., “Traffic Accident Investigators Handbook,” Charles C. Thomas, Springfield, IL, 1980 SAE J1674 Revised AUG2009 Page 2 of 13 3. IDENTIFYING EVIDENCE Types of evidence ordinarily found at the scene of a motor vehicle crash may be classified as follows: 3.1 Positions of Vehicles Which i
11、ncludes cars, trucks, trailers, bicycles, motorcycles, etc. 3.2 Places where Dead or Injured Persons Lie After the crash, particularly if they are outside of vehicles. 3.3 Gouges Made by heavy metal parts which have displaced road or other surface material. 3.4 Scratches and Scrapes Made by weak or
12、rounded metal objects where pavement or other surface material has not been significantly displaced. 3.5 Tire Marks On the pavement or elsewhere if they may be related to the crash. 3.6 Scars On the roadside such as furrows or ruts. 3.7 Debris Various kinds of materials not originally at the scene;
13、such as underbody dirt or snow, loose vehicle glass and parts, vehicle liquids, personal belongings, blood, body tissues, etc. 3.8 Objects Originally on or near the road, which were broken or contacted as a result of the crash. 3.9 Electronic Vehicle Information Some vehicles have an event data reco
14、rder (EDR) which stores vehicle operation information after a crash. Care should be taken to preserve or download this information. 4. PHOTOGRAPHING EVIDENCE Photography (film or electronic/digital) and/or video should be used in the documentation of vehicle crashes. Photography is one of the least
15、expensive items involved in the investigation of a crash, so, a simple guideline is, “When in doubt, photograph.“ SAE J1674 Revised AUG2009 Page 3 of 13 4.1 Photographic Priorities When policy decisions or cost considerations limit the number of photographs, the photographic resources should be mete
16、red according to the following priorities: a. The Crash Scene, before traffic units and people are moved b. Evidence on and off the Road (the crash site) c. Exterior of the Least Damaged Vehicles d. Exterior of the Most Damaged Vehicles e. Interior of the Most Damaged Vehicles f. Interior of the Lea
17、st Damaged Vehicles g. Objects Associated with the Crash (e.g., child restraint seat) These priorities are based upon the following considerations. The crash scene changes the moment the vehicles and victims are moved from their final rest positions. Because this information has a life span of minut
18、es and is often critical to any reconstruction; the relationships of the vehicles to each other, to the roadway evidence and to fixed reference objects should be photographed first. It is often helpful to include a reference object (such as a yard stick or other item of known dimension) in the photo
19、graphs. It is important to realize that the top priority is to record the relationship of vehicles to each other and fixed references (curbs, edges, poles, etc.) and not to detail specific damages. Often, photographs taken for this purpose will be usable for documentation of the damage; but, unlike
20、damage photographs, the scene photographs cannot be made at a later time. The tire markings, liquid spills, and debris remaining on and off the road are usually the next items of evidence to be lost and are therefore listed as the second priority. Sometimes, the arrival of other vehicles disturbs or
21、 obliterates evidence. On other occasions, this information may last for days or weeks or, with some marking enhancements, months. Photographing these items along with the identification markings, discussed later, will enhance their visibility in the photographs and provide additional references for
22、 any follow-on investigation. If there is time available, the vehicles should be photographed to document damages before they are moved. This is preferable because they will be subjected to the potential of further damage in towing operations. If this is not practical, they can be photographed at a
23、later time. The exterior of the least damaged vehicles should be documented first because they are the most likely to be repaired or driven and damaged in further crashes. Conversely, more severely damaged vehicles tend to be either repaired or scrapped less quickly. The interior of the most damaged
24、 vehicle is given priority because its occupants are more likely to have sustained injury. Because the interiors of vehicles offer the most protection to the accident evidence, photography of the occupant contact marks and restraint devices can often be delayed until the final task. Often useful inf
25、ormation can be gained months or years after an accident, particularly when the area of interest is damaged and has no resale value. 4.2 Limited Photography In some cases, a limited number of photographs may be allocated to an investigation. If such a restriction is in effect, this priority list is
26、a good guide. If only a few photographs can be made, overall views of the accident scene, paying attention to the damages as much as practical, are preferred. SAE J1674 Revised AUG2009 Page 4 of 13 4.2.1 The Crash Scene Photographs of the crash scene should be taken at a distance sufficient to inclu
27、de the entire scene within the frame of the photograph. Once this minimum requirement has been fulfilled, further photos of specific objects should be taken at a distance that best shows what you want to show. Initial photographs should be taken well back from the accident vehicles and other objects
28、 of interest so that the entire crash scene is located within the frame of the photograph. Whenever possible, a nearby fixed reference object or other involved vehicle should be captured in the frame. A fixed reference could be a manhole cover, telephone pole, centerline marking, sidewalk or road su
29、rface seam or imperfection, bridge, guardrail, or sign. An object of known dimensions or a measurement tool such as a yard stick may also be helpful to include in the photo. The best photographs will include the intersection of the reference object and the ground plane. This is because most maps of
30、highway crash scenes are two-dimensional representations of the road surface (or ground plane). Photos which do not show this intersection are sometimes difficult to interpret in terms of location on the roadway. The relationship of vehicles to the reference object and the markings on the roadway is
31、 the principle reason for making a map. Photographs taken from an elevated position (e.g., car hood, extension pole, nearby overpass, fire truck ladder, or lift bucket) often provide the best perspective for viewing this intersection. Wide angle lenses are at an advantage in high angle perspectives;
32、 however the photographic distortion they produce should be considered as a tradeoff. One photograph showing a pair of involved vehicles is often more valuable than two photographs showing each vehicle individually. This benefit can be greatly enhanced when a fixed reference point is also visible in
33、 the cameras field of view. Photographs which show the relationship of vehicles to tire marks, loose debris, gouges in the pavement, liquid spills, and damage to roadside objects are also valuable in documenting the scene. As with multi-vehicle photographs, there is more value if the items pictured
34、(vehicles, etc.) can be linked to fixed objects at the scene. At times, this linkage can be created by marking the pavement surface with the techniques discussed later. Photographs of victims after they have been moved from their accident rest positions are generally a lower priority. Medical record
35、s usually provide detailed injury information if it is needed. On the other hand, photographs of bloodstains or victim impact evidence at the crash site, referenced to fixed objects or to a full view of a vehicle, can be invaluable. 4.2.2 The Crash Site The crash site is distinguished from the crash
36、 scene by the passage of time and the rearrangement or removal of vehicles or other evidence. Photographic documentation of the site can often be delayed for favorable weather, lighting, or traffic conditions, especially when critical items of evidence have been highlighted. Tire marks, ruts, or lon
37、g gouges should be photographed along their axes (in the direction they were made) and perpendicular to their axes, if resources permit. If the marks, for example, are too long to show much detail in a single, comprehensive photograph, then overlapping views should be taken of shorter ground segment
38、s which chain the items of evidence together along the path of propagation. Each element of physical evidence at the accident site should be photographed at least twice, preferably from different directions. Whenever possible, two or more angles should contain a fixed reference object within the fra
39、me. 4.2.3 The Vehicles In detailing vehicle damage, at least four photographs per vehicle should be considered a minimum. The preferred views would show the full front, rear and sides at a right angle to the original surface with a minimal border between the viewing frame of the camera and the subje
40、ct image. It is especially important to document both damaged and undamaged areas. If film is limited, two planes (end and side) may be captured in one corner-view. SAE J1674 Revised AUG2009 Page 5 of 13 If possible, the original four views may be augmented by corner views. Resources permitting, clo
41、se-ups may then be taken of the damaged region, particularly of “witness“ marks which associate interactions between specific objects. An impression, for example, may exist in a radiator of one vehicle from the corner of the bumper of an impacting vehicle. It is important to link close-up photos to
42、general area photos to provide a perspective on location. It is desirable to photograph all the damaged parts of a vehicle from different directions and different distances to show the depth of crush. Overhead photographs as well as photographs of the undercarriage also provide a great deal of addit
43、ional information. Photographs of the interior of vehicles should be framed so as to show as much occupant contact damage as possible. Occupant contact can occur to the headliner, sun visors, and trim around window and door openings, as well as to the instrument panel, windshield, steering wheel, se
44、atback, and doors. Be alert for this and for contact to other surfaces such as the hood or deck lid in extreme collisions when documenting occupant impacts. For interior surfaces a flash and a wide-angle lens are a great advantage. The restraint system photographs should emphasize marks left by occu
45、pant loading on “D“ rings, deformed mounting brackets, broken plastic covers on belt buckles, or occupant contact marks on airbags. 5. MARKING THE SCENE EVIDENCE After the crash results have been observed, they may then be marked to: a. Facilitate comparison with the photographs, and b. To preserve
46、the key items for later measurement 5.1 Using Only One Point One point will adequately locate relatively small things such as: a. Grooves, gouges, or groups of gouges less than 1 m (3 ft) across (mark the middle of the group or item). b. Collision scrubs or other tire marks less than 1 m (3 ft) (mar
47、k the middle of the item). c. Small scrapes or dents in guardrails, posts, and trees. d. Spatter areas and puddles less than 1 m (3 ft) across. e. Small debris areas. f. Vehicle parts that are detached. 5.2 Using Two or More Points Two or more points are needed to locate such things as: 5.2.1 Curved
48、 Tire Marks Two end-points if the marks length is apparent. One or more intermediate points when the mark is more than 2 m (6 ft) long. 5.2.2 Straight Marks with Angles, Crooks, Gaps, or Other Irregularities in Them Locate each end and any irregularity. SAE J1674 Revised AUG2009 Page 6 of 13 5.2.3 L
49、arge Debris Areas Three to six points may be located on the perimeter of the debris, along with a central mark at the point of maximum concentration. 5.3 Uniform Scene Marking Symbols It is a good policy to take a few photographs of the overall scene prior to any marking or other modification on the part of the investigator. Subsequent photographs which contain the symbols are much easier for the viewer to understand when the key points of ev
