From: sbharris@ix.netcom.com(Steven B. Harris)
Newsgroups: sci.med
Subject: Re: Research into alcohol
Date: 20 Dec 1998 01:41:45 GMT

In <367C33E7.A39B0EEE@gw-tech.com> Carey Gregory <cgregory@gw-tech.com>
writes:
>
>Happy Dog wrote:
>
>> It was noted that my brother almost missed the cyclist. A difference of
>> a quarter second would have saved him. Assuming that extra quarter
>> second existed, what would the situation have been with an older driver
>> with slower reflexes? Should there be a requirement for drivers to pass
>> a reaction time test? Should it be criminal to have a reaction time
>> greater than the standard?
>
>Criminal? No. But a tough question nonetheless. I think there has to be
>some minimum capability. There are drivers out there who have a hard time
>not walking into fixed objects, much less driving into moving objects at
>highway speeds in congested traffic. OTOH, a car is a true measure of
>independence in the US and Canada for a great many people. Taking a car
>away is a serious change in most people's lives, and loss of driving
>privileges often signals the end of independent living for the elderly.
>Where to draw the line isn't an easy question, but there has to be a line
>somewhere. The elderly's independence can't be traded for the live's of
>others.



COMMENT:

    Yep.  More time hasn't been spent on this, because to a large
extent the healthy elderly do compensate for their slower reaction
times by driving more slowly, more cautiously, only in daytime and good
weather, and so forth.  So accident rates rise only modestly with age of
the driver, after middle age.  I have many geriatric patients who
voluntarily stay off freeways and use only surface streets to do
shopping, etc.  And (thank God) the most common type of dementia
(Alzheimer's) often interferes with ability to find one's way in city
traffic from place to place, before it seriously impairs procedural
tasks like obeying routine traffic signs and coordinated driving
opperations.  Simply not being able to FIND the local Safeway, or find
their way home afterward, gets a lot of people off the roads long
before they are too demented to know to stop at a red light, or for a
pedestrian, etc.   Perhaps the most dangerous brain problem associated
with aging is the small peri-ventricular strokes typical in
multi-infarct dementia, which quite often differentially affect leg
coordination as well as thinking.  In driving, this is an especially
deadly combination.

     Statistically, it's young men who cause auto accidents.  And if
you've ever been tailgated at 5 feet in the middle lane by some Nimrod
in a pickup truck who evidently doesn't understand the either the
concept of passing, or the idea that you can't make heavy traffic part
for you by riding bumpers-- then you know why.  The little old
grey-haired lady who drives 10 mph under the speed limit, with her eyes
just above the dashboard and looking through (not over) the steering
wheel, may occasionally be the cause of some accidents, to be sure.
But not very many.  By both common experience and accident statistics,
she generates more frustration than danger on the roads.

                             Steve Harris, M.D.