Expert Witness Journal Issue 63 October 2025 - Flipbook - Page 19
To address this, forensic analysis was required to
establish exactly what had happened, whether the
HGV driver could have reasonably been expected to
notice the impact, and whether the actions of the car
contributed to the incident.
slightly from their original paths before the
collision occurred. This was a crucial 昀椀nding as
it demonstrated that neither vehicle was entirely
maintaining its lane, which helped explain how
the initial contact occurred. Also, this data
suggested that the car was not maintaining a
steady position and was also partially responsible
for the circumstances that led to contact.
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Tachograph Data Review:
The digital tachograph installed in the HGV was
examined to assess speed and driving patterns
and behaviour in the lead-up to the incident.
Although the tachograph is not speci昀椀cally
designed as a collision investigation tool, it can
provide valuable information that greatly assists
the investigative process.
•
Tachographs are designed to monitor driving
hours and rest periods; they also record speed
and distance data at regular intervals. The
tachograph in this case con昀椀rmed that the HGV
was travelling at a steady cruising speed, within
legal limits, and not engaging in any erratic
behaviour or unsafe manoeuvres.
Above, visual representation of the motorway road layout and vehicle positions at
the time of the HGV 1 and HGV 2 collision with the car
The Challenge:
The central question to this case was whether the
HGV driver had failed in their duty of care by not
noticing the presence of the car and causing the
initial contact. The risks were signi昀椀cant, as the case
could have led to a criminal conviction for careless
driving.
Expert analysis was
investigation needed to:
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essential
because
This data helped to reinforce that the driver was
operating the vehicle appropriately.
the
Determine the precise movements and
positioning of both vehicles leading up to the
collision.
Establish whether the HGV driver could have
seen the car prior to the collision using the
vehicle’s mirrors.
Interpret tachograph data to understand vehicle
speed and positioning.
Conduct a mirror survey to accurately map the
driver’s 昀椀eld of vision and identify any blind
spots.
Present the 昀椀ndings in a clear and objective way
that would assist the court in understanding the
technical evidence.
The Findings:
To answer the key questions raised in this case, a
detailed forensic investigation was conducted. By
combining physical evidence, digital modelling,
vehicle data, and scienti昀椀c research, the court were
provided with a clear and objective reconstruction
of the incident.
Above, Tachograph data from the HGV, assessing speed and driver behaviour
The investigation involved several essential steps:
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Analysis of Vehicle Positions and Movements:
Through examination of impact marks on
both the car and the HGV, the investigation
established that both vehicles had moved
EXPERT WITNESS JOURNAL
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17
Mirror Survey and Blind Spot Mapping:
A comprehensive mirror survey was undertaken
to establish what the HGV driver could and
could not see at the time of the collision.
OCTOBER/NOVEMBER 2025
