Accidents happen quickly, so recalling the precise sequence of events leading up to them is sometimes elusive, even for witnesses directly impacted by the incidents. But the incident is really just the beginning, opening the door for investigations and accident claims, neither of which proceed without accurate information about the accident.

In order to get a handle on what transpired, investigators and analysts rely on detailed reconstructions of accidents assembled with assistance from witnesses, victims, and accident scene investigative experts.
Recreations Help investigators
Once the moment has passed, accident details are gone forever, unless they are resurrected by accident investigators. And until the re-creation process starts to unfold, it is inconceivable to imagine the number of specific details contributing to accident outcomes.
In car accident cases, one of the first things officials attempt to establish is the position of vehicles and pedestrians at the time the incident occurred. By theoretically placing all the players in authentic physical positions, especially relative to one another, it is possible to conceive how things began to unfold. Skid marks, damage to vehicles, traffic signals, and other physical evidence is examined for tell-tale accident signs, which help point to accurate vehicle positioning.
After the proximate location of each vehicle and pedestrian involved in the accident is adequately established, accident re-creation specialists go about analyzing the movement of the same accident participants. By establishing speeds and directions of travel for each vehicle, officials further embellish the accident snapshot being re-created.
The angles of impact and other vehicle evidence found at accident scenes provide valuable clues into the speeds and trajectories of the vehicles involved. The information is analyzed later, to determine who is to blame for the accident, and to establish whether or not any of the drivers were acting recklessly. Sometimes individual accounts, from those involved in accidents, do not match-up with evidence present, further complicating the investigation.
All of the physical evidence is logged into the comprehensive accident report, including sketches and illustrations. Photographic evidence is also included, to support theories and probabilities presented by accident scene investigators.
Ambient conditions at the time of each accident are also included in accident reports. Surface conditions, especially during precipitation events, are strong contributing factors to vehicle collisions. Mitigating circumstances, like snow, rain, and ice help explain the causes of accidents, but they do not absolve participants from responsibility. On the contrary, when road conditions are slippery or hazardous at the time of an accident, it is often determined that drivers fail to respond properly. Driving too fast for conditions is a commonly cited offense.
Interviews Support Investigation Efforts
Once the physical characteristics of an accident scene have been generally outlined, investigators turn to actual accounts of the events, for reinforcement. Each driver is interviewed, as well as passengers travelling in their vehicles.
Bystanders, not involved in the accident, provide valuable insight, because they do not have strong stakes in the investigation outcome - one way or another. Objective viewpoints confirm, or deny, those accounts provided by drivers and available evidence. Whenever possible, information is sought from individuals who witnessed the accident from a variety of positions. By expanding the frame of reference, investigators hope to narrow the margin for error, and thwart any attempts at driver dishonesty.
Summaries of interviews are included on accident reports, compiled from information collected at the scene, soon after an accident occurred. Fresh data is always the most accurate, in terms of portraying the actual course of events. As time passes, details become blurred and witnesses second-guess their own recall abilities. Accident reports are built on timely information, so that they can be consulted later without compromising the facts.