Re: Seatbelts

[Doug Craigen <dcc@ESCAPE.CA>]

Ludwik Kowalski wrote:
...
> was large enough to make the 0.5% difference significant.
>
> In this case 0.5%  --> about 10% reduction in the number of
> deaths. Ten percents of ~ 40,000 (deaths per year in the US) is
> ~ 4000 lives saved per year. I suppose that airbags are much
> more effective. Is there an objective evidence for this?
> Ludwik Kowalski

The two are not one-or-the-other.  In fact, if you are small in stature
you should especially wear a seat belt to protect you from the air bag.
This should make perfect sense to a physicist.  Getting hit in the face
by an air bag while its expanding at 200 mph is going *hurt*!  Also the
design is obviously to provide a cushion in front impact collisions.
Good as far as it goes, but its not a general protection device.

When used inappropriately air bags can injure and even kill.  Gruesome
examples of such abound (decapitation of an infant in a parking lot
fender-bender is one that comes to mind).

Air bags are designed to be used *with* seatbelts not *instead* of
them.  Here's a quote from http://www.nhtsa.dot.gov/airbags/HwySafety/
"Most drivers need only buckle up to avoid the risk of a serious airbag
injury. Only a small proportion of belted drivers are potentially at
risk,"

Here's another quote from
http://www.nhtsa.dot.gov/people/injury/airbags/seatbelt/poin-cou.htm

Myth: "I don’t need to wear a seat belt. My car has an air bag."

Fact: Air bags are supplemental restraints and are designed to be
used with seat belts. They help protect adults in a frontal crash, but
they don’t provide protection in side or rear impact crashes or in
rollovers. Seat belts are needed for protection in all types of crashes
and work well with air bags to provide optimum safety. In fact, seat
belts help prevent air bag injuries by keeping occupants away from
deploying air bags.