🚀 go-pugleaf

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E. Faubion wrote:

> Mike Sweeney <msweeney@nospam.lr.net> wrote:
>
> >> "Coefficients of Friction of Various Roadway Surfaces" copyright 1990.
> >> Sounds to me like you're looking at something else.
>
> >And it has always been that way:
>
> >Possible Ranges of Pavement Drag Factors for Rubber Tires:
>
> (snip)
>
> The word wrap went bonkers on this end so I didn't try to quote it
> however that is the correct chart.  As I'm sure you noticed the only
> figures that include 1.0 or greater on the upper end of the possible
> ranges are for new pavement.
>
> >I keep getting the nagging feeling that he is occasionally confusing
> >cornering forces with CoFs.  Maybe?
>
> Possibly, however cornering forces aren't going to exceed the existing
> CoF the roadway has to offer that vehicle during hard braking unless
> there is a significant superelevation involved.   The CoF is a
> function of time/distance/speed.  If the speed is constant the CoF is
> zero.
>
> Maybe calling it by it's alternate name of drag factor will avoid the
> confusion.  The formula for determining the drag factor, f, where
> speed and distance are know is f = S^2/30d.
>
> With a steady speed the distance is infinity and the factor is zero.
>
> email address can be found at:
> http://www.geocities.com/Heartland/Prairie/6123/

  Geez, Earl.  Don't go all technical on me.  I read the book with an
interest, but I'm not signed up for the first course, On-Scene Crash
Investigation (an extention of the Academy's teachings) until Sept.

I just look at the chart that was given out to the recruits; there's one in
the book.  You just run a test by doing a stop/skid and measuring the
distance.  Then match it up with the chart, and hold a straight edge on the
chart.  I'll get into the math in the classes, I'm sure.  I want to sign up
for all 3 (well, 4 if you count m/c accident reconstruction) classes.  I
would do the 3rd in June, `99, and unless I went to something outside would
be as far as I can go here, in state.

It does sound like you may have one potential convert in the group, asking
for more information.  If we only convince one, it is a start.  :)

Illegitimi non carbondum,

Mike