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- Path: sparky!uunet!timbuk.cray.com!equalizer!sdcrsi!xlnt!xlnt.com!david
- From: david@xlnt.com (David Johnson)
- Newsgroups: rec.autos
- Subject: Re: Vehicle size vs. safety (was: Crash Test Info ... )
- Message-ID: <1329@xlnt.COM>
- Date: 21 Jan 93 00:18:30 GMT
- References: <1993Jan18.210534.5984@pcx.ncd.com> <96654@rphroy.ph.gmr.com>
- Sender: postmaster@xlnt.COM
- Organization: XLNT Designs, Inc (XDI)
- Lines: 40
-
- In article <96654@rphroy.ph.gmr.com>, rhaar@albert.cs.gmr.com (Bob Haar) writes:
- |> In article 5984@pcx.ncd.com, johnl@pcx.ncd.com (John Light) writes:
- |> |>In article <mills.727332343@dialup.athena.lkg.dec.com> mills@athena.lkg.dec.com (George Mills) writes:
- |> |>>Also Size seemed to make very little difference. Some big cars did
- |> |>>terrible and some samll ones did great.
- |> |>
- |> |>Crashing into a fixed barrier negates the advantages of size. Think of
- |> |>crashing into a fixed barrier as the same thing as crashing into a copy
- |> |>of your car going your speed head on. The heavier you are, the bigger the
- |> |>impulse from the collision, negating the safety advantage of your bigger
- |> |>car. It is a good test of what it would be like crashing into a concrete
- |> |>abutment, but it isn't a good test of what it would be like to crash into
- |> |>an average car (unless you happen to be driving an average car).
- |> |>
- |>
- |> Let me add some data to this discussion. The following is paraphrased
- |> from "Traffic Safety and the Driver" by Leonard Evans and is based
- |> on the FARS database which contains entries for all on-road vehicle
- |> accidents which result in fatalities.
- |>
- |> The effect of relative mass is more pronounced in two-car accidents,
- |> but even in single-car accidents, the risk of death is higher in
- |> lighter cars. When both types of accidents are combined, a person
- |> in a 900 kg car is 2.8 times as likely to die in an accident as
- |> a person in an 1800 kg car.
-
- The thing about a lighter car is that there is less material to absorb
- the energy. Of course, mass is not the end all in energy absorption.
- The car body can be designed to make it more efficient in absorbing
- energy without transfering it to the passengers.
-
- I remember reading in the newspaper in 1988 that one model of Porshe
- had the second best injury in a collision record of any car. I am sure
- the Porsche is not massive, just well designed so the car absorbs the
- energy rather than the passengers.
-
- --
- David Johnson
- XLNT Designs, Inc. (XDI)
- david@xlnt.com
-