Traffic Investigation Process
Explorers should be able to investigate a traffic accident, obtain witness and victim information, determine
the cause and fault of an accident and properly fill out the state ST-3 Accident Report form. Explorers
should be able to properly clear the scene of an accident calling upon the necessary resources such as EMS,
wreckers, firemen or repair crews.
Traffic accidents are extremely confusing events. How they occur, who or what caused them, and why they
occurred are facts that police must determine. Every peace officer must know the fundamentals of traffic
accident investigation and know how to prepare traffic accident reports. Traffic accidents, resulting in
personal injury, fatality, and property damage in the amount of $1,000 or greater require an on scene
investigation. The State of Texas mandates all peace officers will use the ST-3 state accident form for
reporting traffic accidents to the Texas Department of Public Safety. If additional instruction/information
is needed, contact the Bureau of Statistical Records, Texas Department of Public Safety.
Prompt arrival at the scene of an accident is essential. Safety, however, should be emphasized at all times.
While in route, the officer should maintain contact with the Dispatcher. They should also be on the lookout
for any suspicious or damaged vehicles fleeing the general area.
Arrival at the Scene.
The following steps should be taken upon arrival at the scene of the accident.
While enroute to the scene, the officer should obtain as much preliminary information as
possible concerning the accident. Such information includes:
– Time of notification
– Who notified the officer and how
– Weather and visibility conditions
– General information as to seriousness of the accident–injuries, hit and run,
amount of traffic congestion, etc.
– Whether or not additional support is proceeding to the scene, such as wrecker,
ambulance, or additional Police patrols
By obtaining such information prior to arrival at the scene, the investigators may
more quickly and efficiently respond to the needs of the situation.
Questioning and taking statements of witnesses and victims should be done at the scene. If this is not
possible, statements should be taken as soon as possible at the hospital, police station or homes of those
involved. Names, number and contact address of witnesses should be noted on the ST-3 accident report.
All parties should be separated when questioning them, but in a safe location like on the sidewalk, not in
the roadway. Make sure the parties exchange names and phone numbers before leaving the accident scene.
After gaining all the information possible from all persons involved in the accident, the investigator begins
to examine the physical condition of the scene and to record his observations.
Vehicle Final Rest Position
The examination should start where the vehicle came to final rest. Debris or broken parts from vehicles,
with other indications, will help locate the key event and indicate the paths of the vehicles involved. Marks
or traces such as skid or scrape marks help the investigator locate pertinent points accurately. All marks,
puddles, bits of metal and contents of vehicles must be located and their positions measured and recorded.
Skidmarks are very important since they show position and direction of travel, evasive action or unlawful
behavior. Note especially things that would help locate the point of first contact, such as changes in
skidmarks, chips in pavement and damage to roadside objects.
Path of Vehicles
The investigator should next retrace the paths of the vehicles involved. Note visibility, condition of signs
and signals, road surface condition, traffic volume, angles of view and possible distractions.
Vehicle Search and Inspection
A careful inspection of vehicle equipment and contents is necessary. Items affecting vehicle control should
be particularly checked, such as tires, brakes, lights, steering, signals and safety equipment. For example, it
is important to know whether a tire blew out as a result of the accident, or whether a tire blowout was a
possible contributing factor of the accident. This fact can be determined by analyzing skid and scuff marks.
Contents of the vehicle may also give important information concerning the identity, residence, occupation,
destination and position of vehicle occupants.