Road Traffic Collisions

Written by Dr. D. Rao

Vehicle of transportation are responsible for a great number of fatalities all over the world. Ideally, Forensic Pathologist should visit the scene of death. in vehicular accidental deaths, retrospective visit may also be helpful in making conclusion about the death. photographs should be an integral part of the scene investigation A meticulous Autopsy helps to study the Nature and Pattern of Injury,Cause of death and circumstances

Surrounding the death which in turn may influence the Road Construction, Saftey precautions in Motor Vehicles and also help evaluate standards in Management of Victims of Road Traffic Collusions in the Emergency Medical services.

(A) Injuries to Pedestrains: Three patterns of injury are often seen:
(1) Primary impact injuries (the first part struck),
(2) Secondary impact injuries (further injuries caused by the vehicles).
(3) Secondary injuries, (injuries caused by the victims striking other objects such as the ground).

In primary impact injuries, the part of the body involved depends upon the position of the person in relation to the vehicle when struck. The injuries also depend upon the relative heights of the various parts of the vehicle, i.e., bumper, radiator, door handles, etc. If a person is struck from behind, the back of the legs are first struck. If the foot is fixed a fracture results and the buttocks and back will come in contact with the vehicle. He may sustain a fracture-dislocation of the lumber or thoracic spine. If the feet slide forward the whole body will fall backward with a secondary impact of the head against the windshield, or he may be thrown into the air or to one side and strike the ground. If the person is facing the vehicle he may sustain intra-abdominal and intra-thoracic injuries. When he is thrown clear of the vehicle he may sustain head injuries. Frequently, bumper  injuries are at different levels on the two legs or absent on one leg, which suggest the victim was walking or running when struck. An impact against a mud-guard or head lamp may cause fracture of the pelvis or fracture-dislocation of the sacro-iliac joints. The pubic ramus opposite to the buttock or hip involved is usually fractured. If the victim is struck from behind, striaelike superficial tears of the abdomen or the inguinal regions are seen due to over-stretching of the skin. When a pedestrian walks into the side of a vehicle, crushing abrasion or tears on the side or front of the face are produced. The chest or loin may be injured with fractured ribs and rupture of lung, diaphragm, spleen or liver. Tearing wounds may be caused by protruding objects such as door handles, or with cuts from broken glass. The most extensive fractures are produced by the head striking a flat surface. If the person is run over there may be:

(1) Tyre marks

(2) Abrasions and lacerations

(3) Burning of the skin.

(4) Deep crushing of the trunk or limbs with rupture of internal organs.  
  1. Injuries to cyclist and motor cyclists: The cycle is hit, and the person is thrown violently to the ground or into some other object or on the car. In being thrown he may injure the groins or legs by entanglement with handlebars or projecting levers or mirror and sustain tears. The head or shoulder may hit some object or they may be run over by the vehicle. Fractures of the skull are common due to secondary impact with ground.
  2. Injuries to occupants of the Vehicles: The driver may be thrown forward. The horn boss may buckle the sternum and produce a transverse fracture and crush the heart or split the aorta. The heart, aorta and the lung root may be pinned and split against the spine. The wheel rim may crush the liver spleen or kidney. The throat may be crushed across the top of the steering wheel. These are known as “the steering wheel impact type of injuries”. If the driver puts force or his hands on the steering wheel to avoid impact on his chest, he may sustain injuries to wrists or forearms. If he applies breaks, fractures of the femur or pelvis, may occur. The driver and front passengers may split the head or face on the wind screen, or may sustain a fracture-dislocation of the cervical spine due to ducking of the head or being thrown up as well as forward. In head on crash the passengers move forward or sustain abrasions and lacerations on the shins and knees or fracture of one or both patellae. The femur or the pelvis may be fractured by being thrown against the dashboard or shelfedge. Sometimes the door may spring open and the person may fall out. When the car overturns the occupants may be pinned and crushed, showing traumatic asphyxia. Rarely the occupants are burned, asphyxiated or drowned whilst pinned in interior of a car.


  1. Scene: Tracks leading to and from the scene indicate direction of travel, speed and attempts to stop or avoid collision. The broken head lights, wind-shield, bumper, mudguards, parking lights, mirrors, spotlight etc., should be collected. Skid marks and other road markings are described, measured and photographed. The locations of vehicles, the type of road, the location and positions of victims on the road, distance and direction of the victims from the impact, and size and direction of blood on the road should be noted, photographed and drawings made.
  2. The case vehicles: The vehicles involved in accidents are photographed from various angles to record the type and amount of damage. Measurements of vehicle are made to determine the amount of the formation and collapse of various structures. Photographs of the interior of the vehicle should be taken, especially areas of deformation and of the impact points. Look for human tissue, blood, hair, cloth fibres, etc., at the possible points of impact. 
  3. The accident victims: In fatal accident, photographs of the victim should be taken to show his position relative to the vehicle.
    1. Clothes: The clothes should be examined while still on body to determine any evidence to indicate what part of the vehicle struck the victim. Paint, smudge marks, grease marks and dirt on the clothes must be noted. The clothes may show imprints of tyre, pieces of glass or metals.
    2. The body: The description of nature, size, extent and location of the injuries may identify some wounds on the body with some object or part of the vehicle in question. Primary impact injuries vary in extent and severity in different cases depending on the position of the pedestrian and on the speed of the vehicle and the part of the vehicle hitting the person. The secondary impact injuries should be described.

AUTOPSY: The main objects are

A. Reconstruction of the accident:

  1. Scene investigation is essential.
  2. Drag marks may indicate that the victim had crawled from the vehicle and was not ejected. Injury sustained by dragging or scraping is usually superficial and show typical brush burning.
  3. The victim’s injuries indicate the mechanism of the accident.

B. Cause of the accident:

i. Natural disease processes in the driver.

  1. Epilepsy
  2. Diseases of the heart and blood vessels.
  3. Hypoglycaemia
  4. Rupture of congenital aneurysm of the cerebral vessels.
  5. Brain tumour
  6. Poor sight or hearing as a result of disease or ageing.

ii.Other causes: Alcohol, Barbiturates, tranquilizers, etc., Carbon-monoxide.

iii.Suicide: Suspicion may arise from the circumstances preceding the accident, e.g., family quarrels, financial crises, threats of suicide, history of depressing, suicide note, etc. In all cases the absence of skid marks and a high speed impact against a highway object which is not particularly hazardous are significant factors.

iv.Other factors: Mechanical failure and Poor design and maintenance of highway.

v.Psychic factors: Disorganization of skilled  reactions may occur in persons who are emotionally upset or suffer from anxieties.

vi.Pedestrians: Cardiovascular or cerebrovascular disease, poor vision, impaired hearing and reduced mobility.

C. Cause of death:

  1. Severe blunt force injuries will point to a traumatic cause of death
  2. Severe natural disease alone or in combination with significant trauma will point to a natural cause of death
  3. Minor trauma may be sufficient by affecting diseased organs or vial areas, e.g., nervous centers of the brain or the conduction system of the heart.

D. Manner of death:
  1. Accident
  2. Accident and natural disease combinations
  3. Suicide:
    • Single occupant crashing into a fixed object.  
    • Pedestrian walking or running in front of moving vehicle. 
    • Other methods employed for suicide: (a) Drugs plus accidents. (b) Suicidal incised or stab wounds plus accidents. (c) Poisoning plus accident. (d) Homicide: (1) Deliberate running down of victim or vehicle. (2) Hit and run (failure to stop and render aid).

A. To identify the driver and reconstruct the positions of the victims of the accident: The driver can be identified by:

  1. Position in the vehicle upon discovery
  2. The presence of steering wheel impact type of injuries
  3. Finding of paint or glass from the door on the driver’s side on the victim’s body or clothes
  4. Finding of cloth fibres, hair and tissue from the suspected driver on the driver panel, door or glass on the driver side or in the steering wheel and columns.
  5. The brake or accelerator pedal design imprinted on the sole of the shoe.
  6. Matching of the blood group of the driver with that of the driver panel, driver and steering assembly.
  7. Finger prints on the steering wheel
  8. Specific injuries caused by objects so positioned in the vehicle that a passenger could not have been so injured.
  9. Witness to crash having no vested interest in the crash.

B. The passengers:

  1. By position in vehicle upon discovery.
  2. Finding of paint or glass from the door on the victim’s body or clothes
  3. Finding of cloth fibres, hair and tissue from the passenger on the doors and inside of the vehicle
  4. Matching of the blood group of the passengers with that of the blood and different parts of inside of the vehicle.
  5. Specific injuries caused by objects so positioned in the vehicle that the driver could not have been injured.

C. Do not know whether driver or passenger:

  1. Confusing cross-transfer of evidence between vehicle and occupant.
  2. No injury pattern clearly indicating whether driver or passenger
  3. Ejection of occupants
  4. No witness

D.  The pedestrian:

1. Injuries which fit a predicted pattern:
  1. Point of impact
  2. Bumper fractures
  3. Specific injuries that fit striking objects, e.g., patterned abrasions and contusions,
  4. 'Moving head' type of coup-contre-coup cerebral contusions
2. Cross-transfer of physical evidence:
  1. Transfer of grease, paint or broken glass from striking objects to victim
  2. Transfer of blood, hair, fibres and tissue to the vehicle.
  3. Patterned imprints of fabric in paint or dust on the vehicle
  4. Dents in metal at impact points that fit with the pedestrian's injuries

ii) Evidence from a witness.

E. Do not know; body lying on the road: I) Rarely may have no external injuries and be a vehicle-pedestrian accident victim ii) Injuries may not be visible, e.g., fracture of cervical vertebrae. Iii) Hit and run: no vehicle to examine for transfer of evidence. Iv) A dead person on the road may be run over by the vehicle.

F. Individual precipitated either accidentally or deliberately from the vehicle:

  1. Permit rapid stop and following vehicle may run over or strike the precipitated individual.
  2. Individual deliberately precipitated from the vehicle: (i) Usually dumped in darkness or in unraveled area. (ii) High level of alcohol or drugs, or dead or incapacitated by injury. (iii) Pattern of injury may not fit with the scene where found.
  3. To differentiate injuries caused by being hit from those caused by being run over.
  4. To identify the vehicle in cases of hit and run:
  5. The clothes may show a tyre tread pattern,
  6. Matching studies of blood type, hair, dirt, grease, paint, oil, rust, etc, found on the victim and vehicle.
  7. Measurement of the leg fractures from the heels of the feet, and the height of other body injuries sustained from protruding part of the vehicle.
  8. The body or clothing of the victim may show oil, rust, paint, glass pieces, etc., from the vehicle.
    1. To determine the significance of previous injuries in case of delayed death: Previous injuries in case of delayed death: Morphologic proof that the trauma can be traced to the time of the accident will prove causal relationship, in delayed traffic deaths.


  1. Collect all information about the circumstances of the crash including police investigation reports and photographs.
  2. Do inspect the vehicle.
  3. Take photographs and draw diagrams of all external evidence of injury.

Collect, preserve and retain anything that is likely to establish a correlation between the pedestrian victim and the offending vehicle, e.g., hair, blood, clothing, paint, grease, glass, etc.

Doctors Responsibilities:To determine the cause of death.
  1. To confirm that death was due to injuries suffered in the accident.
  2. Determine the extent of these injuries
  3. Detect any disease or factors that could have precipitated or contributed to the accident or death.
  4. To detect any criminal activity associated with the death
  5. Document all findings for subsequent use in either criminal or civil actions
  6. Establish positive identification of the body especially if it is burnt or severely mutilated.

Examination of the scene:

  1. Time and date of accident.
  2. Name(s) of decedent(s), whether Driver, passenger or pedestrian
  3. Position’s of victims and degree of injuries
  4. Brief background information about the decedent if suicide suspected
  5. Findings indicating suspicion of foulplay
  6. Make and position of vehicle and degree of damage
  7. Behaviour of vehicle prior to crash
  8. Points of impacts and relative positions of vehicles (if more than one)
  9. Estimated speed of vehicle and posted speed limit
  10. Condition of road.
  11. Skid marks, brake marks
  12. Weather conditions (rain, fog) and lighting condition


  1. Reconstruction of the crash to determine its cause
  2. Determination of the cause of death.
  3. Determination of the Manner of death
  4. Establishment of the identity of the decedent
  5. Identification of the driver and reconstruction of the positions of the victims prior to the accident
  6. Differentiation of injuries caused by being hit from those caused by being run over
  7. Identification of the automobile in the case of hit and run incidents.
  8. Determination of the significance of these injuries in a case of delayed deaths

Documentation of the findings to aid legal processes. 
  1. Scene investigation with photographs
  2. Collection of evidence-clothing, paint traces, glass splinters, oil spots, rust, bloodspot
  3. Complete autopsy with recording of injuries by description, drawings and photograph
  4. Follow up studied – Examination of vehicle, driver, and alcohol intoxication.