belt AUDI A4 2017 User Guide

Assist
Audi pre sense rear
Description
App lies to: ve hicles w ith Audi side assist
If the risk of a collision is detected, the following
functions can trigger:
- Reversible tensioning of the front safety belts
at the corresponding speeds .
- Closing the windows and sunroof*.
- Inflating the side bolsters* in the seat backrest
and seat surface.
- Switching on the emergency flashers with in-
creased frequency
l ).
The message Audi pre sense. ~ page 108,
fig. 104 will warn you about the danger.
Aud i drive select*: the function is not active de­
pending on the mode selected.
A WARNING
- To reduce the risk of an accident, please
note that the side assist* radar sensors do
not always detect every object.
- Pre sense rear does not react to people, ani­
mals or objects that are crossing the vehi­
cle's path or that are difficult to detect.
- Reflective objects such as guard rails, heavy
rain and ice can impair the function of the
radar sensors and the ability to detect a col­
lision risk .
(D Note
The radar sensors can be displaced by impacts
or damage to the bumper, wheel housing and
underbody. Pre sense rear can be impaired by
this . Have an authorized Audi dealer or au­
thorized Audi Service Facil ity check their func­
tion.
(0 Tips
- The pre sense rear functions switch off
when towing a trailer.
- The pre sense rear functions may also
switch off if there is a malfunction in the
side assist* system.
1> This is not ava ilab le in some co untri es.
110
Audi pre sense city
' Description
App lies to : vehicles wit h Audi pre sense city
Within the limits of the system, pre sense city
can warn you of impending collisions with
vehicles and pedestrians and initiate the applica­
ble braking maneuver if needed. Pre sense city is
active at a speed of 6 mph (9 km/h) and higher.
A pedestrian warning can occur at speeds up to 50 mph (85 km/h), and vehicle warnings can oc­
cur at speeds up to 155 mph (250 km/h). A pre
sense city braking maneuver is possible at speeds
up to 50 mph (85 km/h).
Warnings
App lies to: vehicles wit h Aud i pre sense city
The system recognizes various dangerous situa­
tions. The
early warning occurs when:
- a vehicle driving ahead brakes sudden ly,
- your own vehicle approaches a sign ificantly
slower vehicle or stationary vehicle in the direc­
tion of travel.
- a pedestrian is standing in the lane or is moving
into the lane.
When this warning occurs, it may only be possi­
ble to avo id a collision by swerving or braking
strongly. The message
Audi pre sense.
~ page 108, fig. 104 and a warning tone will
warn you about the danger.
Additionally, a jerk on the brakes may occur as an
acute warning when there is an impend ing colli­
sion . If you do not react to the acute warning, pre
sense city can brake to the point of complete de­
ce leration within the limits of the system. This
reduces the vehicle speed in the event of a colli­
sion. The message
Audi pre sense. also ap­
pears.
The following functions are triggered in conjunc­
tion with pre sense basic/rear:
- Reversible tensioning of the front safety belts .
- Closing the windows and sunroof*. ..,

<( a, .... N ,....
N .... 0 0
3 a,
-Inflating the side bolsters* in the seat backrest
and s eat surfac e.
Aud i drive select*: the function is not active de ­
pending on the mode selected.
A WARNING -,..___
-Pre sense city cannot overcome the laws of
physics. It is a system designed to assist and
it cannot prevent a collision in every circum­
stance. The driver must always intervene.
The driver is always responsible for braking at the correct time . Do not let the increased
safety provided tempt you into taking risks.
This could increase your risk of a collision .
- The system can deploy incorrectly due to
system-specific limits.
- To reduce the risk of an accident, please
note that the camera does not always detect
every object .
- Pre sense city does not react to animals,
crossing or oncoming vehicles, objects such
as bars, railings or railcars, and objects that
are difficult to detect~&.
in General infor­
mation on page 97.
A WARNING
Pre sense city may be restricted or not availa­
ble in the following example situations:
- in heavy fog, rain, spray or snow.
- when there are visual obstructions, such as
glare, reflections or var iations in light.
- when it is dark .
- if the camera window or the windshield is
dirty, iced over, damaged or covered .
- when driving on snow, ice or loose ground .
- on sharp curves.
- if the ESC was restricted or switched off .
- when towing a trailer.
- when the driver's seat belt is unfastened.
- up to ten seconds after sw itching on the ig-
nition.
1 ) Thi s is no t avail able in some c oun tries.
Assist
(D Note
Impacts or damage to the camera mount on
the windshield can displace the sensor . Pre
sense city can be impaired by this. Have an au­
thorized Audi dealer or authorized Audi Serv­
ice Facility check their function .
(i) Tips
-You can cancel the system braking interven­
tion if you accelerate considerably or swerve
away .
- Keep in mind that pre sense city can brake
unexpectedly. Always secure any cargo or
objects that you are transporting to reduce
the risk of damage or injury.
- When there is a malfunction in the camera,
the pre sense city functions also switch off.
Settings in the
Infotainment system
Applies to: vehicles with Aud i pre sense
.,. Select in the Infotainment system: I MEN U! but­
ton
> Vehicle > left control button > Driver as­
s ist > Audi pre sense.
Audi pre sense-
switch On/Off. You can switch
the pre sense functions on and off with th is.
If the system is switched off, it switches on again
automatically once the ignition is switched on
again
l ).
Early warning1
) -the early warning can be
switched off or the pre sense city/front warning
point
( Early /Mediu m/La te) can be set .
Driver messages
Applies to: vehicles with Aud i pre sense
fll Audi pre sense currently restricted. Restrict­
ed sensor vision due to surroundings. See own­
er's manual
This message appears if the radar sensor and
camera view is obstructed, for example by leaves,
snow, heavy spray or dirt . If necessary , clean the .,..
111

Intelligent Technology
E DR is needed. In add ition to the vehicle manu­
facturer, other parties, such as law enforcement, that have the specia l equipment, can read the in­
formation if they have access to the vehicle or the EDR.
Some state laws restrict the retrieval or down­ loading of data stored by ED Rs insta lled in a vehi ­
cle for the express purpose of retrieving data af­
ter an accident or crash event without the own­
er's consent.
Aud i will not access the EDR and/or s imilar data
or give it to others -
- unless the vehicle owner (or lessee if the vehi ­
cle has been leased) agrees; or
- upon the officia l req uest by the po lice; or
- upon the or der of a co urt of law or a govern-
ment agency; o r
- fo r the defense of a laws uit throug h the judicial
discove ry process.
- Audi may also use the data for research about
vehicle ope ration and safe ty performance or
provide the da ta to a third party for rese arch
purposes w ithou t identifying the s pecific vehi ­
cle or information about the identity of its own­
er or lessee and on ly after the recorded vehicle
data has been accessed.
Vehicle control modules
Your ve hicle is a lso equipped wi th a n umber of
e lectronic contro l modu les for vario us veh icle
systems, s uch as engi ne management, emission
control, a irbags, and safety belts.
T hese e lectro nic con trol mod ules re co rd da ta
du ring normal vehicle operation that may be
needed by trained technicians for diagnostic and
repair p urposes. The recording capability of these
mod ules is limited to data (no sound is record­
ed). On ly a small amount of data is actually re­
corded over a very limited per iod of time, or stor­
ed when a system fau lt is detected by a control
mod ule . Some of the data stored may re late to
ve hicl e speed, di rect ion, or bra king, as well as re ­
s tra int system use and performa nce in the even t
of a crash. Stored d ata can also only be read and
downloaded with special equipment that is di ­
rect ly co nnecte d to the ve hicle.
140
(D Tips
Your vehicle may be eq uipped w ith Aud i con­
nect. Yo ur use of certain Aud i connect fea­
tures requires wire less services that are pro­
v ided by a third party wireless telecommuni­
cations provide r. Fo r details regarding how in­
formation ob tained through Aud i connec t is
collected, p rocesse d, transmitted, used, a nd
shared, plea se see yo ur contra ct with the
wireless tele commun ic a tions pr ovi der and t he
"About A udi conne ct" t ab in yo ur vehicle' s In ­
fotainment system:
I MENU ! button > Audi
connect
> right control button > About Audi
connect .

Driving sa fe ty
Driving safety
General notes
Safe driving habits
Please remember -safety first!
This chapter contains important information,
tips, instruct ions and warn ings that you need to
read and observe for your own safety, the safety
of your passengers and others. We have summar­
ized here what you need to know about safety
be lts, a irbags, child restra ints as well as child
safety. Your safety is for us
priority number 1 . Al­
ways observe t he i nfo rmation and wa rn ings in
this section - for your own safety as well as tha t
of yo ur passengers.
The information i n this section applies to all
model ve rsions of your vehicle . Some of the fea­
tures descr ibed in t his sec tions may be s tanda rd
eq uipment on some models, or may be optional
equipment on others. If yo u are not sure, ask
your author ized Audi dealer.
A WARNING
-Always make sure that you follow the in­
structions and heed the WARNINGS in th is
manual. It is in your inte rest and in the in­
te rest of your passengers .
- Always keep all of the Owner's Lite rature
manuals in your Audi when you lend o r sell
yo ur vehicle so that this important informa­
t ion w ill always be availab le to the dr iver
and passenge rs.
- Always keep the Owner 's Lite rature handy
so that you can find i t easi ly if yo u have
ques tions.
Safety equipment
The safety features are part of the occupant re­
straint system and work together to help reduce
the risk of injury in a wide variety of occident si t­
uations.
Your safety and the safety of yo ur passenge rs
should not be left to chan ce. Advan ces in tech­
nology have made a var iety of features av ail ab le
to help reduce t he risk of injury in an accident .
236
The following is a list of just a few of the sa fety
features in your Audi :
- sophis tic ated safety be lts fo r dr ive r and all pas-
senge r seat ing pos itions,
- safety belt p re tensioners,
- be lt height adjustment for the front seats,
- head restraints for each seating position,
- front airbags,
- knee airbags fo r the front seats,
- side airbags in the front seats and outboard
rear seats *,
- side curtain airbags,
- special LA TC H anchorages for the outboard rear
seats and top tether anchorages for chi ld re ­
straints for all of the rear seats,
- adjustab le steering col umn.
These ind iv idual safety features, can work to­
gether as a system to he lp protect you and your
pa ssengers in a wide range of a cciden ts. These
fea tures canno t wo rk as a sys tem if they a re not
a lways cor rec tly ad juste d and cor rect ly used.
Safety is everybod y's responsibilit y!
Important things to do before driving
Safety is everybody's job! Vehicle and occupant
safety always depends on the informed and care­
ful driver .
For your safety a nd the safety of your passen ­
gers,
before driving alway s:
.,. Make sure that all lights and signals are operat­
ing correctly .
.,. Make sure that the tire pressure is correct .
.,. Make sure that a ll windows a re clean and afford
good v is ibility to the outs ide.
.,. Se cur e all luggage and othe r items ca refully
q page 242.
.,. Make sure that noth ing can i nter fere with the
peda ls .
.,. Adjust front seat, head restraint and mirrors
correctly for yo ur height.
.,. Instruct passengers to adjust the head re­
straints according to their he ight .
.,. Make sure to use the rig ht child restraint co r­
rectly to protect chi ldren
q page 2 77 , Child
safety. ..,.

.. Sit properly in your seat and make sure that
your passengers do the same¢
page 61, Front
seats .
.. Fasten your safety belt and wear it properly . Al­
so instruct your passengers to fasten their safe­
ty belts properly ¢
page 245 .
What impairs driving safety?
Safe driving is directly related to the condition of
the vehicle, the driver as well as the driver's abili­
ty to concentrate on the road without being dis ­
tracted.
The driver is responsible for the safety of the ve­
h icle and all of its occupants . If your ability to
drive is impaired, safety risks for everybody in the
veh icle increase and you also become a hazard to
everyone else on the road ¢_& .T herefo re :
.. Do not let yourself be distracted by passengers
or by using a cellular telephone .
.. NEVER dr ive when your dr iv ing ability is im­
paired (by medications, alcohol, drugs, etc.) .
.. Observe a ll traff ic laws, rules of the road and
speed limits and plain common sense.
.. ALWAYS adjust your speed to road, traffic and
weather condit ions.
.. Take frequent breaks on long trips . Do not drive
for more than two hours at a stretch.
.. Do NOT drive when you are tired, under pres­
sure or when you are stressed.
A WARNING
Impai red dr iv ing safety increases the risk of
ser ious personal inju ry and death whenever a
vehicle is being used .
Driving safety
Correct seating position
for passengers
Proper seating position for the driver
The proper driver seating position is important
for safe, relaxed driving.
F ig. 20 5 Correct seating pos it io n
For your own safety and to reduce the risk of in­
jury in the event of an accident, we recommend
that you adjust the driver 's seat to the fo llowing
pos ition:
.. Adjust the driver's seat so that you can easily
push the pedals all the way to the floor while
keep ing your knee(s) slightly bent¢_& .
.,. Adjust the angle of the seatback so that it is in
an upright position so that your back comes in
full contac t wi th it when you dr ive.
.. Adj ust the steer ing wheel so that there is a d is­
tance of at least 10 inches (25 cm) between the steering whee l and your breast bone¢
fig. 205.
If not poss ible, see your author ized A udi dealer
about adaptive equipment.
.. Adjust the steering wheel so that the steering
wheel and airbag cover points at your chest and
not at your face .
.,. Grasp the top of the steering wheel with your
elbow(s) slightly bent .
.. Ad just the head res tra int so the upper edge is
as even as possib le w ith the top of yo ur head.
If
that is no t possib le, try to adjust the head re­
straint so that it is as close to this position as
possible .
.. Fasten and wear safety belts correctly
¢page 248 .
.. Always keep both feet i n the footwell so that
you are in control of the veh icle at all t imes .
237

Driving safety
For detailed information on how to adjust the
driver's seat, see
¢ page 61.
A WARNING
Drivers who are unbelted, out of position or
too close to the airbag can be seriously in­
jured by an airbag as it unfolds. To help re­
duce the risk of serious personal injury:
- Always adjust the driver's seat and the
steering wheel so that there are at least
10 inches (25 cm) between your breastbone
and the steering wheel.
- Always adjust the driver's seat and the
steering wheel so that there are at least
4 inches (10 cm) between the knees and the
lower part of the instrument panel.
- Always hold the steering wheel on the out­
side of the steering wheel rim with your
hands at the 9 o'clock and 3 o'clock posi­
tions to help reduce the risk of personal in­
jury if the driver's airbag inflates.
- Never hold the steering wheel at the
12 o'clock position or with your hands at
other positions inside the steering wheel
rim or on the steering wheel hub. Holding
the steering wheel the wrong way can cause
serious injuries to the hands, arms and head if the driver's airbag deploys.
- Pointing the steering wheel toward your face decreases the ability of the supplemen­
tal driver's airbag to protect you in a colli­
sion.
- Always sit in an upright position and never
lean against or place any part of your body
too close to the area where the airbags are
located.
- Before driving, always adjust the front seats and head restraints properly and make sure
that all passengers are properly restrained.
- Never adjust the seats while the vehicle is
moving. Your seat may move unexpectedly
and you could lose control of the vehicle.
- Never drive with the backrest reclined or
tilted far back! The farther the backrests are
tilted back, the greater the risk of injury due
to incorrect positioning of the safety belt and improper seating position.
238
-
- Children must always ride in child safety
seats ¢
page 2 77. Special precautions ap­
ply when installing a child safety seat on the
front passenger seat¢
page 253.
Proper seating position for the front
passenger
The proper front passenger seating position is
important for safe, relaxed driving .
For your own safety and to reduce the risk of in­
jury in the event of an accident, we recommend
that you adjust the seat for the front passenger
to the following position :
.,. Adjust the angle of the seatback so that it is in
an upright position and your back comes in full
contact with it whenever the vehicle is moving.
.,. Adjust the head restraint so the upper edge is
as even as possible with the top of your head.
If
that is not possible, try to adjust the head re­
straint so that it is as close to this position as
possible
¢ page 62.
.,. Keep both feet flat on the floor in front of the
front passenger seat.
.,. Fasten and wear safety belts correct­
ly¢
page 248.
For detailed information on how to adjust the
front passenger's seat, see ¢
page 61.
A WARNING
Front seat passengers who are unbelted, out
of position or too close to the airbag can be
seriously injured or killed by the airbag as it
unfolds. To help reduce the risk of serious
personal injury:
- Passengers must always sit in an upright po­
sition and never lean against or place any part of their body too close to the area
where the airbags are located.
- Passengers who are unbelted, out of posi­
tion or too close to the airbag can be seri­
ously injured by an airbag as it unfolds with
great force in the blink of an eye.
- Always make sure that there are at least 10
inches (25 cm) between the front passen-
ger's breastbone and the instrument panel.
Ill>

-Always make sure that there are at least
4 inches (10 cm) between the front passen­
ger's knees and the lower part of the instru­
ment panel.
- Eac h passenger must always sit on a seat of
t h eir own and properly fasten and w ear the
safety belt belonging to that seat.
- Before driving, always adjust the front pas­
senger seat and head restraint properly.
- Always keep your feet on the floor in front
of the seat. Never rest them on the seat, in­
strument panel, out of the window, etc. The
airbag system and safety belt will not be
able to protect you properly and can even in­
c rease the risk of injury in a crash.
- Never drive with the backrest recli ned or
t il ted fa r bac k! The farther the backrests are
t il ted back, the greater the risk of i njury due
to incorrect posi tioning of the safety bel t
and improper seating position.
- Children must always ride in child safety
sea ts¢
page 2 77. Spec ial precaut ions ap­
ply when installing a chi ld safety seat on the
front passenger seat
c::> page 253.
Proper seating positions for passengers in
rear seats
Rear seat passengers must sit upright with both
feet on the floor consistent with their physical
size and be properly restrained whenever the ve­
hicle is in use.
To reduce the r isk of injury caused by an incorrect
seating position in the event of a sudden braking
maneuver or a n accident, you r passengers on the
rear bench seat must always observe the follow­
in g:
.,. If there are passengers on the outer rear seats,
adjust the head restraints so the upper edge is
as even as possible with the top of your head. If
that is not poss ible, try to adjust the head re­
straint so that it is as close to this position as
poss ible.
If there is a passenger in the ce nte r
rea r seat, slide the head res traint upward
¢page 62.
.,. Make s ure that the seatback is sec urely latched
in t he upright position
c::> page 65.
Dr iving safety
.,. Keep both feet f lat in the footwell in front of
the rear seat.
.,. Fasten and wear safety belts properly
c::>poge248 .
.,. Make sure that children are always properly re­
strained in a child restra int that is appropr iate
for their size and age
c::> page 2 77.
_&. WARNING
Passengers w ho are improperly seated on the
rear seat can be serio usly inju red in a crash.
- Each passenge r must always sit on a seat of
their own and properly fas ten and wear the
safety bel t belonging to tha t seat.
- Safety bel ts only offer maxim um protect ion
when the seatba ck is securely latched in t he
upright pos ition and the safe ty belts are
properly positioned on the body. By not sit­
ting upright, a rear seat passenger increases
the risk of personal injury from improper ly
positioned safety belts!
- Always ad just the head restraint proper ly so
that it can give maximum protection.
Proper adjustment of head restraints
Correctly adjusted head restraints ore on impor ­
tant port of your vehicle's occupant restraint sys­
tem and con help to reduce the risk of injuries in
occident situations.
F ig. 20 6 Head restra int: v iewed from t he front
The head rest raints mus t be correct ly adjusted to
achieve the best protection.
.,. Ad just t he head restra ints so the upper edge is
as even as possib le w ith the top of you r head . If
that is not possib le, t ry to adjust the head re-
stra int so that it is as close to this pos it ion as .,.
239

Driving sa fe ty
possible . Position* the head restraint as close
as possible to the back of your head.
~ If there is a passenger in the center rear seat,
slide the head restraint upward .
Adjusting head restraints
r=-, page 62.
A WARNING
All seats are equipped with head restraints .
Dr iv ing without head restraints or with head
restraints that are not proper ly adjusted in­
creases the risk of ser ious or fatal neck injury
dramatically . To help reduce the r isk of injury:
- Always dr ive with the head restraints in
place and properly adjusted.
- Every person in the vehicle must have a
properly adjusted head restra int.
- Always make sure each person in the vehicle properly adjusts their head restraint. Adjust
the head restra ints so the upper edge is as
even as possib le w ith the top of your head.
If that is not possib le, t ry to adjust the head
restra int so that it is as close to t his position
as possib le.
- Never attempt to adjust head restrai nt
wh ile driving. If you have dr iven off a nd
mus t adjust the driver headrest for any rea­
son, fi rst stop the vehicle sa fely before at ­
tempting to ad just the head restra int .
- C hildren must always be p roper ly restrained
in a chi ld restraint that is appropriate fo r
their age and size
i=-, page 2 77.
Examples of improper seating positions
-
The oc cupant restraint system can only reduce
the risk of injury if vehicle occupants are properly
seated .
Imp roper seating positions can cause se rious in­
jury or deat h. Safety belts can only work when
they are proper ly positioned on the body. Im ­
proper seating positions reduce the effectiveness
of safety belts and w ill even increase the r isk of
in ju ry and death by moving the safety be lt to crit­
ical areas of the body. Improper seating posit ions
also increase the risk of ser ious injury and death
when an airbag deploys and strikes an occupant
who is not in the prope r seat ing pos ition . A driver
240
is responsible fo r the safety o f all veh icle occu ­
pants and especia lly for children. Therefore :
~ Never allow anyone to assume a n incorrect
seating posi tion when the vehicle is being used
q _& .
The following bulletins list on ly some samp le po ­
s itions that w ill increase the r is k of se rious injury
and death. Our hope is that these examples wi ll
make yo u more aware of seating positions that
are dangerous.
Therefore , whenever the vehicle is moving :
-neve r sta nd up in the vehicle
- neve r stand on the seats
- never k neel on the seats
- never ride w it h the seatback recl ined
- never lie down on the rear seat
- never lean up against the instrument panel
- neve r sit on the edge of the seat
- neve r sit sideways
- neve r lean out the w indow
- never put your feet out the window
- neve r put your feet on the instrument panel
- never rest your feet on the seat c ushion or back
of the seat
- never ride in the footwell
- never ride in the cargo area
A WARNING
Imp roper seating positions inc rease the risk
of ser ious personal inju ry and death whenever
a veh icle is being used.
- Always make sure that all veh icle occupants
stay in a proper seating posit ion and a re
proper ly restrained whenever the vehicle is
be ing used.
Driver's and front
passenger's footwell
Important safety instructions
A WARNING
A lways make su re that the knee airbag can in­
flate w ithout inte rfe rence. Objects between
yourself and the airbag can in cr ease the risk

Safety belts
General information
Always wear safety belts!
Wearing safety belts correctly saves lives!
This chapter explains why safety belts are neces­
sary, how they work and how to adjust and wear
them correctly. .. Read all the information that follows and heed
all of the instructions and WARNINGS.
A WARNING
Not wearing safety belts or wearing them im­
properly increases the risk of serious personal
injury and death.
- Safety belts are the single most effective
means available to reduce the risk of serious
injury and death in automobile accidents.
For your protection and that of your passen­
gers, always correctly wear safety belts
when the vehicle is moving.
- Pregnant women, injured, o r physically im­
paired persons must also use safety belts.
Like all vehicle occupants, they are more
likely to be seriously injured if they do not
wear safety belts. The best way to protect a
fetus is to protect the mother -throughout
the entire pregnancy.
Number of seats
Your Audi has a total of five seating positions:
two in the front and three in the rear. Each seat­ ing position has a safety belt.
A WARNING
Not wearing safety belts or wearing them im­
properly increases the risk of serious personal
injury and death.
- Never strap more than one person, includ­
ing small children, into any belt.
It is espe­
cially dangerous to place a safety belt over a
;;§ child sitting on your lap.
~ -Never let mo re people ride in the vehicle
:::l than there are safety belts available. 0 0
3 Safety belts
-Be sure everyone riding in the vehicle is
properly restrained with a separate safety
belt or child restraint.
Safety belt warning light
Your vehicle has a warning system for the driver
and front seat passenger to remind you about the importance of buckling-up.
Fi g. 208 Safety belt warn ing light in the instrument clus ·
te r -en larged
Before driving off, always:
.. Fasten your safety belt and make sure you are
wearing it properly.
"' 0 N ... m
.,. Make sure that your passengers also buckle up
and properly wear their safety belts.
.,. Protect children with a child restraint system
appropr iate for the size and age.
The warning light . in the instrument cluster
lights up when the ignit ion is switched on as a re­
minder to fasten the safety belts . In addition,
you w ill hear a warn ing tone for a certain period
of time.
Fasten your safety belt and make sure that your
passengers also properly put on their safety
belts.
A WARNING
-
- Safety belts are the sing le most effective
means available to reduce the risk of serious
injury and death in automobile accidents.
F or your protection and that of your passen­
gers, a lways correctly wear safety belts
when the vehicle is moving .
- Failure to pay attention to the warning light
that comes on could lead to personal injury.
245

Safety belts
Why use safety belts?
Frontal collisions and the law of physics
Frontal crashes create very strong forces for peo­
ple riding in vehicles .
Fig. 209 Unbelted occupants in a veh icle headi ng fo r a wall
Fig. 210 T he vehicle c rashes into the wall
The physical principles are simple. Both the vehi­
cle and the passengers possess energy which var­ ies w ith vehicle speed and body weight . Engi­
neers call this energy "k inetic energy."
The higher the speed of the vehicle and the
greater the vehicle's weight, the more energy
that has to be "absorbed" in the crash.
Vehicle speed is the most significant factor .
If
the speed doubles from 15 to 30 mph (25 to 50
km/h), the energy increases 4 times!
Because the passengers of this vehicle are not us­
ing safety belts
r:!) fig. 209, they will keep moving
at the same speed the vehicle was moving just
before the crash, unti l something stops them -
here, the wall
r:!) fig . 210.
The same principles apply to people sitting in a
vehicle that is involved in a frontal collision . Even
at c ity speeds of 20 to 30 mph (30 to 50 km/h),
the forces acting on the body can reach one ton
246
(2,000 lbs. or 1,000 kg) or more . At greater
speeds, these forces are even higher.
People who do not use safety belts are also not
attached to their vehicle. In a frontal collision
they will also keep moving forward at the speed
their vehicle was travelling just before the crash.
Of course, the laws of physics don't just apply to
frontal collisions, they determine what happens in all kinds of accidents and collisions .
What happens to occupants not wearing
safety belts?
In crashes unbelted occupants cannot stop
themselves from flying forward and being in­
jured or killed . Always wear your safety belts!
Fig. 211 A drive r not wea ring a safety belt is vio len tly
t hrow n forward
Fig. 212 A rear passe nge r not wear ing a sa fety belt will f ly
forward an d str ike the driver
Unbelted occupants a re not able to res ist the tre­
mendous forces of impact by holding tight or
bracing themselves. Without the benefit of safe­
ty restraint systems, the unrestra ined occupant
will slam violently into the steering wheel, in­
strument panel, windshield, or whatever e lse is
in the way
r:!) fig . 211. T h is impact with the vehi ­
cle interior has all the energy they had just be-
fore the crash.
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