"James C. Reeves" > wrote in message
...
>
> "Jeff Strickland" > wrote in message
> ...
> |
> | > wrote in message
...
> | > Date: Mon, 8 Nov 2004 23:59:42 +0100 (W. Europe Standard Time)
> | > From: Stefan Lesser [redacted for spam control]
> | > Subject: BMW series 5 disables Dynamic Stability Control and ABS
> | > (originally posted in comp.risks)
> | >
> | > After two accidents involving police cars of Berlin, Germany, at first
the
> | > drivers were blamed and appointed to a security training. But taking
into
> | > consideration the driver's nearly identical reports, which claimed
that
> | the
> | > cars on-board drive dynamic control systems had failed, BMW took on
and
> | > inspected the case. The result was: Yes, after an emergency brake
> | exceeding
> | > a certain preset pressure on the pedal, all stability systems are
disabled
> | > and can only be re-enabled by switching off the ignition for five
> | > seconds...
> | >
> |
> |
> | Let me see if I understand, if the driver makes an emergency stop - or
> | similar type of manuver - the vehicle control systems can disable
themselves
> | without warning the driver this has happened, then in a subesquent
manuver
> | where the driver might be relying on the features, he might find them
not
> | available? That seems like a problem that should require immediate
response
> | from BMW.
> |
> | As much as I think the vehicle control systems should always work, if
they
> | are turned off for any reason, including but not limited to driver
> | selection, the driver should be informed that the features are not
currently
> | available. All this means is that a light should turn on if the vehicle
> | control systems - ABS and Traction Control - have either been switched
off
> | by the driver, or have gone off for some reason that only the car knows
> | about.
> |
>
> Let me see if I understand the basics of what is happening here. The
stability
> control systems are really doing virtually nothing to improve
safety...only
> allowing the driver to push the car to it's new edge, which they are
doing. No
> wonder the HLDI's FAQ page on simple ABS system says that insurance loss
data
> shows NO REDUCTION in accidents (comparing insurance loss statistics of
cars
> with ABS with cars without ABS). Apparently what so many have said is
true!!!
> These systems just allow drivers to push the envelope further and does
nothing
> to actually improve safety "per-se".
>
>

Keep in mind the drivers in the report were police, so they are more likely
to approach "the edge", and remain there more often and longer than the rest
of us mortals. And, by my reading, the problem the police had wasn't that
the systems let them down, the problem is that the systems shut off, so the
police were thinking a behavior they had trained for would occur, but the
fact is it didn't occur at all. In short, the police drivers expected
something to happen that did not happen, and the result was apparently a
wreck.

The report made no mention that I can recall of civilian drivers having
these issues. This doesn't mean civililan drivers haven't had them, but it
is possible that the trouble is related to the police spec that the cars are
built to. But, it seems to me that the systems worked fine, then shut off
for some unknown reason, and it is this shutting down without any indication
that is what needs to be fixed. The system should not shut down unless the
driver turns it off, and if it does shut down with or without driver input,
the driver should be told that the system is inactive.