A BLACK MARK IS NOT
JUST A BLACK MARK
A Black Mark is not just a Black Mark – Skidmarks, What they Do and
Don’t tell us…
We have all seen black marks on the highway. When investigating a crash, we need to
know what they are and what they can tell us.
A Black Mark is not just a Black Mark – Skidmarks, What they Do and
Don’t tell us…
We have all seen black marks on the highway. When investigating a crash, we need to
know what they are and what they can tell us.
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SKIDMARKS: WHAT THEY DO AND DON’T TELL US...
JOE W. ATHERTON, ACTAR 697, ACCIDENT TECHNOLOGY, INC.
Anti-lock Brake Marks
Beginning point
Beginning point
Ending point
Ending point
A skid mark is one or more marks caused
by A skid a tire mark or tires is one that or have more decelerated marks caused
to
by the a point tire or of tires actually that melting have decelerated rubber on
to
the point roadway.of actually The usual melting cause rubber is braking.on
In some instances, the wheel is locked and
skidding; in some instances, (anti-lock
brakes) the wheel rotation is greatly
reduced. Skid marks from a vehicle
without anti-lock brakes, are mostly
straight and equally prominent from side
to side. They sometimes begin faintly and
end abruptly. Distinguishing
characteristics are the parallel striations
within the mark as seen here.
the roadway. The usual cause is braking.
In some instances, the wheel is locked and
skidding; in some instances, (anti-lock
brakes) the wheel rotation is greatly
reduced. Skid marks from a vehicle
without anti-lock brakes, are mostly
straight and equally prominent from side
to side. They sometimes begin faintly and
end abruptly. Distinguishing
characteristics are the parallel striations
within the mark as seen here.
A vehicle with anti-lock brakes
will still maintain the ability to
steer. As a result, the marks
may not be straight.
Additionally, the marks may
appear intermittent as the
wheel automatically locks and
releases.
A vehicle with anti-lock brakes
will still maintain ability to
steer. As a result, the marks
may not be straight.
Additionally, the marks may
appear intermittent as the
wheel automatically locks and
releases.
Anti-lock Brake Marks
With the proper information, a skid mark will provide us with the minimum speed of a vehicle.