tire marks and its types and its image and how it was formed

Tire marks and its types

1. 1
Tire Marks
By
Mr. Subhendu Mandal
B. Sc. Forensic science

2. CONTENTS
INTRODUCTION
CHARACTERISTICS OF TIRE MARK
TYPES OF TIRE MARK
SKID MARK
SCUFF MARK
IMPORTANCE OF TIRE MARK
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3. INTRODUCTION
• Tire tracks are the impressions left by tires on the surface
onto which a vehicle drove.
• But tires don’t leave impressions on every surface.
• If the surface is soft or semi-soft, such as mud, dirt, or snow,
the tire will leave an imprint under the weight of the vehicle.
• And if the surface is hard, such as road pavement, the tire
might still leave a trace, if dirt or dust will be there.
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4. • Tires are made of semi-hard rubber and are
characterized by class and individual characteristics.
• Class characteristics includes size and general
patterns.
• Whereas Individual characteristics includes
regular wear and tear as well as accidental cuts or
holes.
• These characteristics may be reproduced in the
tracks left by the tire, depending on the surface and
the circumstances under which the track occurred .
CHARACTERISTICS OF TIRES

5. TYPES OF TIRE
MARKS
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TIRE MARKS
SKID MARKS
SCUFF
MARKS
ACCELER
ATION
SCUFF
DECELER
ATION
SCUFF
FLAT TIRE
SCUFF
SIDE
SCUFF
COMBINIT
ION
SCUFF
YAW
MARKS

6. SKID MARKS
•Skid marks caused by tires on roads
occur when a vehicle wheel stops rolling
and slides or spins on the surface of the
road.
•Skid marks can be analyzed to find the
maximum and minimum vehicle speed
prior to an impact or incident.
•Skidding can also occur on black ice or
diesel deposits on the road and may not
leave a mark at all.
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7. SCUFF MARKS
•Scuff marks are marks made by a tire that
is rotating and sliding at the same time on
pavement or another surface.
•Scuff marks are left on the road by tires
that are sliding or scrubbing while the
wheel is still turning.
•The impression of rib marks are absent in
scuff marks.
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8. Acceleration Scuff
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TYPES OF
SCUFF
MARKS
Deceleration Scuff
Side Scuff
Flat tire Scuff
Combination Scuff
Yaw Marks

9. Acceleration Scuff
•If the drive tires are spinning
faster than the vehicle speed,
heavy burn marks will be left on
the pavement at the initial point of
acceleration.
•The tire rib may be visible in the
center of the imprint.
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10. Deceleration Scuff
•Declaration marks occur when tires are
spinning slower than the vehicle
because of braking or downshifting.
•When a vehicle brakes a greater
portion of the vehicles weight is
transmitted to the outer edges of the
front tires.
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11. Flat Tire Scuff
•Made by a seriously underinflated or
overloaded tire.
• A partially deflated tire produces
marks that are heavy on the edges and
light in the middle; with a completely
deflated tire, the sidewall touches the
roadway, and rim cuts are commonly
seen.
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12. Side Scuff
•These marks are left by a tire
sliding sideways, without
braking. Close striations are a
characteristic of side scuffs.
•The striations are narrow,
parallel, light grooves,
scratches or stripes.
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13. Combination Scuff
•These are combinations of sliding
with decelerating or side scuffs.
• They can be caused by a vehicle
braking and steering at the same
time, or steering and applying power
at the same time.
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14. Yaw Marks
•These are caused by a turning
movement in the tires while the
vehicle is still traveling in the same
general direction.
•They are normally wider than skid or
scuff marks. However, they may be
narrower when just the edge of a tire
is in contact with the road surface.
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15. IMPORTANCE OF TIRE MARKS
•Just like fingerprint, shoe print or any other print, the tire tracks are also
an unavoidable part of crime scene investigations to enable identification
of the vehicle that left them.
•Tire tracks are usually found in road accident scenes or in the access and
escape routes of other crime scenes.
•By going with proper investigation it is easy to find the vehicle used to
commit the crime or else which vehicle was used for the getaway or to
dumb the body or to dumb any evidence.
•We can also get sure about the suspect by matching the tire marks found
on the scene with the one taken from the vehicle.
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16. Thank you