RE: Fuel Efficient Cars (was Oil Economics)

From: Edwin Evans (ektimo@pacbell.net)
Date: Sat Feb 08 2003 - 14:23:26 MST

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    Brain Atkins wrote:
    > which is worth more safety-wise in a collision: modern
    > safety design and airbags or simple mass?

    Mass. It's not even close. Even if both cars are bigger, it still helps.

    ---
    http://www.scienceservingsociety.com/pubs/AmericanScientistTEXT.htm:
    When a vehicle crashes, its size is the attribute of the vehicle that most
    affects the occupants' injury risk. Larger vehicles offer more protection in
    crashes mainly because they are heavier. Their larger dimensions also
    provide increased protection. Relations between injury risk and vehicle
    weight are among the most reliably established findings in traffic-safety
    research. When a car crashes into another that is twice as heavy, the driver
    in the lighter car is 12 times as likely to die as the driver in the heavier
    car. But such large weight disparities are rare. The most common weight
    disparity in a U.S. two-car crash is for one car to be 20 percent heavier
    than the other. In that case, the driver of the lighter car is twice as
    likely to die as the driver of the heavier car.
    --
    If cars of the same mass crash into each other, each will undergo identical
    speed changes. However, the risk decreases as the common mass of the
    vehicles increases (Figure 7, right). This effect is not because of the mass
    but because heavier vehicles are generally larger. The large size provides
    more crushable space and therefore more time for the occupants to
    decelerate.
    --
    In 1966, the United States had the lowest traffic fatality rate in the
    world; in the years since then, despite an obsessive focus on vehicle safety
    or arguably because of it, the U.S. ranking in the world has steadily
    slipped.
    The focus on vehicle factors -- factors over which they have no control --
    has encouraged American drivers to regard safety as something out of their
    control.  The American focus on airbags is one example of this. These were
    mandated by a lawyer-led safety agency that claimed safety benefits far in
    excess of published technical estimates [9%] and ignored technical
    information documenting their harmful effects. Before a drug can be
    prescribed in the United States, it must meet two basic standards --
    efficacy and safety. Airbags were not shown to meet either, but they were
    not merely offered to the public, their installation was required. Now, the
    United States is the only country in the world in which it is illegal to
    purchase a new car without a device that is known to increase the net harm
    to women (Dalmotas et al. 1996) and to increase fatality risk in children
    (Glass et al. 2000).
    ---
    Note, the traffic-safety expert who wrote this article also happens to be my
    Dad.
    Buckle up,
    -Edwin
    


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