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Alexander Baldwin
Maurer
Senior Exit Project
21 November 2012
Technology vs. Size
Some people believe that to increase automobile safety one must increase the size
and weight of the automobile. According to the National Highway Traffic Safety
Administration “…a 100-pound reduction in the average weight of passenger cars…
would have a significant adverse impact on safety” (2). By increasing the size and
weight of an automobile it may become safer but it can also severely reduce the gas
mileage of that automobile. It also increases the danger to other cars on the road. By
increasing size and weight of one car the manufacturer may increase that cars safety, but
they are also reducing the safety of those around it. When a large automobile hits a
smaller one, it normally hits above where the majority of the safety features of the car are
designed to be effective. This results in the almost certain injury or death of the occupant
of the smaller vehicle. However, the safety of an automobile is not determined by size
and weight alone. The size and weight of a car can have huge effects on gas mileage and
the safety of other cars on the road. Structural design and internal safety features can
produce a safer car without creating a large, inefficient vehicle.
One of the most important aspects of automobile safety is structural design. The
most important aspect of structural design in an automobile is reducing the intensity of a
crash. To reduce the intensity of the crash, the manufacturers can either increase the
period of deceleration or increase the time over which the occupants feel the deceleration.
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The structural design of a vehicle can help to increase the period of time over which the
occupants feel deceleration during a crash. “…by increasing the total deceleration period
(for example, by lengthening the front end of the vehicle)” (Chan 13). By increasing the
time over which deceleration is felt, the intensity of the deceleration is lessened, resulting
in lessened force being applied to the occupants. Moving the passenger compartment
backwards in the structure of the automobile can increase the period of deceleration. If
the passengers compartment is farther back than that would increase the amount of
material between the passenger and whatever object they are colliding with in a frontal
crash. In Chan’s study he found that 43 percent of fatal crashes were front impact
crashes (18). Increasing the length of the car slightly and using crumple zones can cause
the force of these impacts to be reduced, causing a reduction in the frequency of fatalities
from frontal crashes. Considering that the majority of fatal crashes are frontal, by
increasing the safety in a frontal crash the overall number of fatalities would drop.
Also, the use of roll cages can help prevent injury and death in rollover accidents.
In informative author Donna Latham’s article about racecar safety she describes roll
cages as “a frame made of heavy steel tubes. It helps stop the truck's hard metal body
from crushing the driver during a crash” (12). The roll cage serves as a cage to prevent
the crushing of occupants during a roll over. Should a car roll over and end up on its roof
the roll cage essentially serves as support to prevent the roof from crushing into the
passenger’s compartment. As the installation of roll cages or similar protective measures
is not required in the production of automobiles many do not have them installed. This
leads to an increased rate of death in rollover crashes. According to Chan’s study
approximately twenty percent of fatal crashes are single car rollovers (18). The
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application of roll cages could greatly reduce the over all death rate in roll over crashes.
Considering that the car rolling over causes twenty percent of fatalities in crashes, the
implementation of roll cages could drastically reduce. If roll cages were to become
mandatory in cars, occupants would be less likely to suffer injuries due to crushing when
the weight of the car lands on the roof during a roll. In automobile designer Peter
Derviller’s patent for a lightweight racing car, he describes a lightweight, internal roll
cage (65). Due to the fact that roll cages can be internal and lightweight, they could be
used to reduce the lethality of a rollover during an automobile crash.
Additionally, crumple zones are also a structural design that can help with the
safety of vehicles. According to engineer Stephen Shoap’s patent, “A crumple zone is a
volume that absorbs at least a portion of the energy of a collision and lengthens the time
of the collision event” (21). By absorbing the force and lengthening the collision time the
crumple zones make the car safer in a crash. Essentially, the crumple zone collapses in
on itself at purposefully designated areas in order to allow for the controlled compaction
of certain areas of the car. By doing this, engineers can control where and how a car
crumples, allowing them to exert control over the amount of energy felt during the
impact. By putting crumple zones in areas of the car that were previously not very well
protected, the car becomes safer. Crumples zones are capable of being put in almost
every area of a car because they can be designed to fit almost anywhere. In the Popular
Mechanics article, The Tech Inside, by P.W. Singer, it discusses how Volvo meets the
safety standards for their larger cars with the S40 - a small, compact car – by adding just
eight inches to the crumple zone (94). Volvo does not add any length to the car; they
simply increase the length of an internal safety structure. Considering the effectiveness
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of eight inches of crumple zone to can be reasoned that by increasing the size of crumple
zones in other vehicles, safety can be greatly increased.
Fortunately, work is being done to advocate the advance the use of crumple
zones. According to an investigative hearing before Congress, heard by the
Subcommittee on Transportation, Aviation and Materials, the Subcommittee on
Investigations and Oversight, and the Committee on Science and Technology, one of the
things that should be done to increase the safety of occupants is “Structural research to
work in conjunction with the occupant kinematics to minimize injury” to create
“lightweight energy-absorbing front and side structures” (280). The advocacy by these
committees to perform this research may cause some sort of governmental grant to
whomever performs this research, leading to interested parties looking to come up with
the best way to protect the passengers of a car using these materials.
Furthermore, the positioning and distribution of the engine block has a substantial
effect on automobile safety. In the article, Small Overlap Crashes, published by the
Insurance Institute for Highway Safety, the Institute’s president said “’Nearly every new
car performs well in other frontal crash tests conducted by the Institute and the federal
government, but we still see more than 10,000 deaths in frontal crashes each year’"(2).
The reason for these fatalities is small overlap frontal crashes. According to the same
article, approximately fifty percent of fatalities or serious injuries in frontal crashes are
die to small or medium overlap crashes (3). The article also states that because the small
to medium overlap tests are not performed by anyone other than the IIHS and a small but
unspecified number of manufacturers, those who do not run the test do not prepare their
automobiles for that eventuality. Because of this, the automobile manufacturers designed
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their cars to protect from full frontal crashes, and not frontal overlap crashes. The
designers made full frontal crashes more survivable by condensing the engine block and
placing it in the center of the frontal area of the car. This serves to place more mass
between the passengers and any object that may collide with the center of the front of the
car. In the article it talks about how in early August of 2012 the IIHS began running test
on cars that had previously passed the frontal crash tests (2). This time, though, they
were running tests on small overlap frontal crashes. They discovered that most of the
cars they tested would result in almost certain fatality in a 40-mile per hour crash. The
problem was that the directly in front of the driver is essentially empty and the force was
not absorbed by anything, allowing the force of hitting the wall to drive the steering
column into the driver (4). The IIHS states that while manufactures put crumple zones in
the middle of the front end to protect against frontal crashes, there is little to no
protection between the occupants and the source of the force (4). While this means that
the passenger are very well protected during a full frontal crash, the lack of mass between
passenger and contact point means that the car is absorbing a negligible amount of force.
The lack of any force being absorbed leads to a larger amount of force being passed into
the passenger compartment. The less force that is absorbed during impact means that
more forcing is acting on the occupants, thus making the crash more dangerous to anyone
involved.
Internal safety features play a very important part in car safety. These include
seatbelts and airbags. In the Frontal Offset Crashworthiness Evaluation by the IIHS said,
“The critical values against which the force and moment are compared depend on the
direction of the applied loads” (3). Seatbelts, airbags, and seat design all work together to
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lessen the impact of the crash against the passengers. According to a NOVA, Death
Defying Designs for Car Safety, the seat belt is specifically designed to distribute the
force of the crash over the stronger sections of the body. This helps to reduce the strain
on weaker parts of the human body, increasing the survivability of a crash. With the
increase in technologies for seat belts designers have come up (NOVA) with ways to
make it so that the seatbelt automatically adjusts the speed with which its tension
increases to be better suited for each individual crash. Internal safety technology allows
the manufacturers to use technology that will automatically adjust to better manipulate
the total force applied to the occupant. Additionally, side airbags, padding, and
collapsible steering columns help to prevent injury to the occupants. Side airbags serve
to protect the occupant from slamming their heads into the widows and siding of the car,
while padding on surfaces in the car helps to prevent serious injury from slamming into
the hard surfaces of the car, because the padding serves as a cushion rather than the
passenger striking a metal or hard plastic object. A collapsible steering column helps to
avoid serious injury to the driver in a head on crash. Instead of slamming straight into the
driver, the steering column collapses in on itself. The collapsing of the steering column
absorbs energy and allows for the dissipation of energy before the steering column makes
contact with the driver, reducing the amount of force applied to the driver, and increasing
the likelihood of survival. This also serves to help absorb the force of crashes. Side
airbags prevent occupants from slamming into the windows and frames of the car. All of
these safety measures can be used to help protect passengers without increasing the size
and weight of cars.
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Another internal safety feature that plays a huge role in car safety is seat design.
A report published by the Society of Automotive Engineers stated, “The first was the
benefit in allowing a horizontal or dropping trajectory of the pelvis into the seatback”
(Viano xii). According to NOVA and the Society of Automotive engineers, Volvo and
General Motors have both been working on seat designs that will help reduce the amount
of strain felt by occupants during a crash (xii). The new designs will serve to either
reduce stress on the lower back, reduce the chance of whiplash, or both. The main
problem with most seats is that the rigidity does not allow for the contortion of the seat to
protect from severe back injury or the rotation of the seat lead to the back of the occupant
being bent. David Viano ran tests with the Inland-Fisher-Guide Division to test a new
seat they had created and in the process tested other seats, determining that the most
damage occurred to and occupant when the seatback rotated too much and the passenger
slid up the seat (xiii). IFG created a seat that did not have that amount of seat rotation
and during tests with an unbelted dummy determined that better seats are capable of
protecting and retaining their occupant even while the dummy is unbuckled (xiii). By
changing the way the seat contorts, manufacturers can produce a safer seat for rear end
collisions. These seats would make cars much safer for rear end collisions without
increasing the weight of the car by reducing the chance of severe back or neck injury.
A car does not have to be massive piece of metal in order to be safe. Instead,
manufacturers can use structural design, internal safety features, and the careful
distribution of weight to increase safety. By using all of these techniques, a car can be
made safer without causing to become extremely heavy. This allows for a safer car that
is still fuel efficient and small. Size and weight play a huge role in fuel efficiency, and
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while increasing them may also increase safety, it will reduce the gas mileage and
increase the dangers to other cars on the road. A larger car poses more danger to those
around it than a small car. By using other factors, safe cars can be constructed without
these side effects. Smaller cars can be just as safe as a larger car, if proper safety
measures are taken. If used in conjunction, these factors could help prevent upwards of
forty percent of fatalities. This can lead to a safer road without an increase in gas usage.
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Works Cited
"Death-defying Designs for Car Safety." - Academy of Science. N.p., n.d. Web. 17 Nov.
2012.
Derviller, Peter R. J. Lightweight High Performance Road Racing Vehicle. Michael
Mar, assignee. Patent 5199526. 6 Apr. 1993.
"Frontal Offset Crashworthiness Evaluation." Insurance Institute for Highway Safety.
IIHS, n.d. Web.
Highway Safety: Causes of Injury in Automobile Crashes. Collingdale, PA: DIANE
Pub., 1996. Google Books. Web.
Latham, Donna. "Protecting the Drivers." Superfast Trucks 2007: 12. EBSCOhost.
Web.
"Research & Statistics." IIHS-HLDI. Web. 3 Sept. 2012.
Relationship of Vehicle Weight to Fatality and Injury Risk in Model Year 1 9 8 5 - 93
Passenger Cars and Light Trucks. Rep. no. 808 569.. National Highway Traffic
Safety Administration. NHTSA.
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Shoap, Stephen D. Method and Apparatus for a Shared Crumple Zone. Ruth Ilan,
Assignee. Patent 7699347. 20 Apr. 2010.
Singer, P. W. "The Tech Inside: Safety." Popular Mechanics Oct. 2004: 94.
Small Car Safety Technology: Hearings before the Subcommittee on Transportation,
Aviation, and Materials and the Subcommittee on Investigations and Oversight
of the Committee on Science and Technology, U.S. House of Representatives,
Ninety-seventh Congress, Second Session, November 30, December 3, 1982.
Washington: U.S. G.P.O., 1983. Google Books.
"Small Overlap Crashes." Status Report 14 Aug. 2012: 2-3. IIHS.