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THE
ROYAL SOCIETY FOR THE PREVENTION OF ACCIDENTS
MOTORCYCLING SAFETY POLICY PAPER
JUNE 2006
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Inappropriate
Speed
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Speed
surveys41 show that on 30 mph built-up roads in 2004, almost
half (48%) of motorcyclists exceeded the speed limit, compared
with just over half (53%) of car drivers. On 40 mph built-up
roads, 36% of motorcyclists exceeded the speed limit, compared
with 27% of cars.
On non-built-up single carriageway roads with the national
speed limit of 60 mph, 25% of motorcyclists exceeded the limit,
compared with only 10% of car drivers. On non-built-up dual
carriageways with the national speed limit of 70 mph, 48%
exceeded the speed limit, with 21% travelling faster than
80 mph. On motorways, 59% of motorcyclists exceed the speed
limit, with 28% going faster than 80 mph.
The risk and severity of injury increases with speed. Most
motorcycle accidents occur at relatively low speeds, although
fatal and serious injuries are more likely to be suffered
at higher speeds.
Built-up roads (roads with speed limits of 40 mph or less)
have the highest casualty rate for motorcyclists. Over two
thirds of powered two wheeler casualties occur on built-up
roads, despite the fact that they carry less than half of
motorcyclist traffic. However, only one third of motorcyclist
deaths occur on these roads. 60% of deaths occur on non-built
up roads (speed limits over 40 mph). Only 2% of casualties
and 3% of deaths occur on motorways, which also have the lowest
motorcyclist casualty rate.
Over one third (38%) of the motorcyclists involved in fatal
accidents in one study were considered to have been speeding
before the collision.
The In-depth Study of Motorcycle Accidents42 identified misjudging
the speed required to negotiate a bend as the most common
cause of motorcycle only crashes. Inappropriate speed (both
exceeding the limit and riding within the limit but too fast
for the conditions) was a contributory factor in 9.2% of the
motorcycle accidents studied. However, 58% of the motorcyclists
who responded to the questionnaire survey admitted to always
or frequently breaking the speed limit, but only when they
felt it was safe to do so. Over two-thirds of these experienced
motorcyclists also admitted to sometimes miscalculating bends.
The European Experimental Vehicles Committee’s review43 of
research into motorcycle accidents, also found that the majority
of motorcycle collisions take place at fairly low speeds,
between 30 and 60 kilometres per hour.
A TRL study12 found that approximately 75% of motorcycle accidents
occur at impact speeds of up to 48km/h (30 mph) and 96% at
up to 64 km/h (40 mph). The study also found that almost all
(93%) of the serious and fatal head injuries occur at speeds
of up to 64km/h (40 mph).
These figures suggest that high speed riding and accidents
are not the only area of concern, and that interventions should
also be directed towards motorcycle riding at lower speeds.
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Helmets
and Clothing
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Motorcycle
Helmets
When a motorcyclist’s head hits another object, it is of vital
importance that the energy created in the impact is dissipated
in a controlled manner in order to prevent or reduce the risk
of brain injury. Head and brain injuries can be caused in
very low speed accidents, and motorcycle helmets offer good
protection against such injuries (although they do not guarantee
protection).
In the UK, motorcyclists must wear a helmet when riding on
the road. Helmets sold in the UK must comply with ECE Regulation
22 as amended, British Standard BS 6658 as amended or a European
standard which offers a level of protection which is the same
as, or better than, the British Standard.
A literature review44 of the effectiveness of motorcycle helmets
shows that helmets reduce the risk of fatal head injury by
around 50%. It is sometimes suggested that the extra weight
of a helmet actually increases the risk of neck injuries,
but research has found no evidence to support this. Full faced
helmets offer greater protection against facial and chin injuries
than open-faced helmets, but may slightly increase the risk
of injury to other parts of the head.
However, the study of fatal accidents involving motorcyclists45
found that the helmet came off in 20% of fatal crashes (12%
before the crash and 45% during the crash). There is also
evidence that the protection offered against chin impacts
is inadequate (riders who suffer chin impacts frequently suffer
fractures to the base of the skull - the most threatening
head injury).
Advances in Helmet Technology As effective as motorcyclist
helmets are, they can be improved. Research is underway to
improve the standards for helmets and visors, which may lead
to a rating scheme.
It is also important that helmet design follows motorcycle
user behaviour. With the growth in motorcycle use – especially
as a mode of transport rather than a hobby – the types of
accidents motorcyclists are involved in may change. If there
are more accidents at 30 mph, then helmets should be primarily
designed to mitigate these.
TRL research47 found that current helmets were too stiff to
provide the same protection at lower speeds as they do at
higher speeds. At lower speeds, less energy is generated,
but the helmet does not absorb it as efficiently and a larger
percentage is transferred to the wearer’s cranium. This suggests
that helmet designs need to be optimised to make them more
energy absorbent at lower speeds, and increase the range of
severities that would be survivable for a rider wearing a
helmet. An ideal helmet would efficiently absorb energy over
a wider range of speeds.
Future helmet design also needs to focus on reducing the rotational
acceleration of the rider’s head upon impact. This is frequently
a cause of brain injury, especially when combined with linear
acceleration.
TRL’s Motorcycle Helmet Assessment Project48 assessed the
relationship between helmet design and injury risk, and developed
a new advanced helmet that offers better protection at a larger
range of speeds. It was estimated that if all riders had had
an advanced helmet in the year of the study, then 93 of the
578 (17%) motorcycle fatalities could have been prevented
that year, as could 434 serious injuries.
Unfortunately, the estimated additional cost of the advanced
helmet was £150. Real world use of the helmet and the rate
at which motorcyclists invest in the technology must be taken
into account in order to get a realistic evaluation of its
actual casualty savings. Assuming that 10% of all helmet sales
were the advanced helmet, in the first 5 years of their introduction,
28 lives would be saved and 130 serious injuries prevented.
Once the technology is readily available, a strong case for
the extra investment needs to be put forward to motorcyclists
to achieve rapid sustained sales growth. As mentioned previously,
published comparative ratings for helmets would lead to more
informed consumer choice.
Visors
Riders who use an open-faced helmet need to use a visor or
goggles to protect their eyes from wind, rain, insects and
road dirt. If they normally wear glasses or contact lenses
they must wear them when riding. It is important that visors
and goggles are kept clean, and replaced if they become heavily
scratched as scratches which may distort the view, cause dazzle
from oncoming vehicle headlights or cause sun glare. TRL’s
review of police reports of fatal accidents involving motorcyclists49
identified impaired vision caused by problems with the rider’s
visor as being associated with crashes in which a rider hit
a stationary object.
Some motorcyclists wear sunglasses, tinted visors or goggles,
and have sought a change in the law to legalise very dark
tints, with minimum light transmittance of 18%, for daytime
use. Research50 on the effect of tinted visors on seeing distances
and signal light recognition on unlit roads at night, supports
a minimum level of 50% transmittance. It found that very dark
visors did not fundamentally help wearers to see better in
bright conditions. This research was conducted on fully alert
subjects with good eyesight wearing visors that were in good
condition, and so may have under-estimated the potential problems
caused by the use of dark tinted visors in less good conditions.
The Government has called on standards bodies to encourage
the development of technical solutions to enable longer-term
visor designs to lend themselves equally to both day and night
time use
Riders should not wear tinted glasses, visors or goggles if
riding in the dark, dusk or conditions of poor visibility.
Noise
Regular use of a motorcycle can damage a rider’s hearing52.
At 60 mph noise levels (mainly wind noise) inside motorcycle
helmets can be in excess of 100dB11. Extended exposure to
noise levels of over 90dB can lead to permanent hearing loss.
Noise inside the helmet may prevent the rider from hearing
audible signals, such as horns, sirens and traffic.
Noise levels vary with the style of helmet, whether the motorcycle
has a windscreen and the position of the rider behind the
screen. Research by the University of Southampton using a
wind tunnel showed the main source of noise to be the turbulence
at the edge of the windscreen’s wake acting on the helmet.
Low screens direct the turbulence to the wake of the helmet
and improvements to the helmet seal around the neck can reduce
noise levels on motorcycles with low screens. High windscreens
direct the turbulence to the helmet visor and the forehead
and improvements in the seal between the visor and the helmet
result in an improvement. These modifications can reduce noise
levels by 5 – 8 dB at the ear.
The easiest way for most motorcyclists to achieve a reduction
in noise levels is to wear earplugs. These should be marked
with British Standard BS EN 352-2:2002, the hearing protector
standard for Ear Plugs. Many UK police forces now provide
these for their motorcyclists as part of their health and
safety policy. Riders using earplugs for the first time should
monitor their speed carefully since the earplugs will reduce
their level of feedback from the road environment.
VAT
In the UK motorcycle helmets have been VAT zero-rated since
1974. There were proposals in the European Commission to remove
this exemption. Fortunately, the Government made it clear
that the UK would not remove or reduce this exemption.
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Protective
Clothing
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Leg
and arm injuries are common for motorcyclists who are involved
in crashes, and leg injuries in particular can be serious,
and often cause permanent disability. Good motorcycle clothing
can protect motorcyclists from the wet and cold and from some
types of injury. It is essential that it is comfortable to
wear, does not impede the movements of the rider and provide
protection from the elements - riders who are warm and dry
are much more alert.
European standards have been developed for motorcyclist protective
clothing (which must be CE marked). There is now a wide range
of such clothing available, including one and two-piece suits,
trousers, jackets, boots and gloves, which contain abrasion
resistant materials, such as Gortex, leather or kevlar and
padding or body armour to protect from impact injuries. Good
gloves or gauntlets are essential when riding a motorcycle.
They protect the rider's hands from cold, wet weather, and
from injury if they fall off, and allow the rider to operate
the controls easily. It is equally important to wear good
boots or strong footwear that cover the ankle when riding.
However, as with helmets, there are accidents and injuries
from which the best protective clothing is unable to protect
the rider.
High Visibility Clothing
Protective clothing that contains fluorescent and reflective
material will increase the conspicuity of the rider, and hence
help to reduce the likelihood of an accident occurring in
the first place. In tests of motorcyclists’ daytime conspicuity54,
riders wearing a fluorescent jacket or waistcoat were detected
by observers sooner than riders not wearing any high visibility
garments.
When riding in the dark, riders should wear clothing that
includes reflective materials on the legs and lower body,
as this is where car headlights will shine.
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Rider
Behaviour - Conclusion
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As
with all road accidents, the causes and contributory factors
of motorcycling accidents are varied and complex.
The rider’s skills, training, experience and attitudes are
fundamental to safe motorcycling (although by no means the
only issues). One of the key approaches to improving motorcyclist
safety is to ensure that riders receive appropriate training
when they start (or re-start) to use a motorcycle, that they
receive further training as they progress in their riding
careers, especially as they progress from smaller to larger
motorcycles.
Research is underway to establish the most effective type
of training schemes for different groups of riders and to
develop a range of appropriate courses.
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