Expert Witness Journal Issue 64 December 2025 - Flipbook - Page 74
seriously injured pedestrians contacted untested
areas, with 22% su昀昀ering serious head injuries.
Each of these scenarios presents unique challenges
for injury mitigation and requires targeted design
interventions.
This research formed part of the evidence base
that led to the amendment of Regulation 127 in
March 2025, which extended the testable area using
headform impactors to include the windscreen.
This regulatory update aligns testing protocols
more closely with real-world injury data, addressing
previously overlooked impact zones.
Designing for Safety: Key Impact Zones
To mitigate pedestrian injuries, vehicle designers
focus on three primary impact zones: the bonnet,
bumper, and windscreen. These zones are
responsible for the majority of serious injuries in
pedestrian collisions, and have therefore become
the focus of both regulatory testing and design
innovation.
Head injuries are the leading cause of death in
pedestrian collisions. When a pedestrian is struck,
their head often impacts the bonnet or windscreen,
frequently resulting in skull fractures and/or
traumatic brain injuries. To address this, vehicles are
now tested using headform impactors that simulate
real-world collisions. These tests have driven the
adoption of energy absorbing bonnet designs, active
bonnet systems that lift upon impact, and changes
to vehicle geometry to increase clearance between
the bonnet and engine components.
Figure 2 - The car on the left showing the testing area prior to the
regulation changes. The car on the right highlights the extended test area
including the windscreen
Leg injuries are also common, particularly to the
long bones, and knee ligaments. The bumper and
the leading edge of the bonnet are the primary
contact points. Modern bumpers are designed with
energy-absorbing materials and rounded edges
to minimise injury. Testing protocols use legform
impactors equipped with sensors to measure forces
on bones and joints, ensuring that bumper designs
meet safety standards.
Active Safety Technologies and Innovation
In addition to passive safety features, modern
vehicles are increasingly equipped with active safety
systems designed to prevent collisions altogether.
Technologies such as Advanced Emergency Braking
(AEB) systems with pedestrian detection use sensors
to identify potential collisions and automatically
apply the brakes. Additional systems, including
Intelligent Speed Assistance (ISA), night vision,
and surround-view cameras further enhance driver
awareness and response times.
Studies have shown that AEB systems could
potentially prevent up to 56% of pedestrian
fatalities and serious injuries, provided the collision
parameters fall within the system’s operational
range. However, these technologies are not foolproof
and must be complemented by robust passive safety
features to protect pedestrians when collisions do
occur.
Figure 1 - diagram showing the pedestrian impact areas tested
The Role of Forensic Investigation
The Windscreen Dilemma
Forensic collision investigators play a vital role
in understanding how vehicle design in昀氀uences
pedestrian injury outcomes. Pedestrian protection
is a complex and evolving 昀椀eld that requires
collaboration between engineers, regulators, and
forensic experts. While considerable advancements
have been made, particularly in bonnet and bumper
design, ongoing challenges persist, especially
in areas like windscreen safety and visibility in
heavy vehicles. The integration of active safety
technologies and the expansion of regulatory
Despite advancements in bonnet and bumper
design, the windscreen remained unregulated for
pedestrian head impacts until recently. In-depth
forensic investigations revealed that a signi昀椀cant
proportion of serious head injuries occurred from
impacts with the windscreen, particularly in areas
not covered by existing testing protocols. A 2018
study by the author titled Casualty Bene昀椀ts of
Measures In昀氀uencing Head to Windscreen Area
Protection, highlighted that 42% of killed or
EXPERT WITNESS JOURNAL
71
DECEMBER/JANUARY 2025-2026
