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Re: NMA STUDY



In article <3v1f6b$idk@news-e1a.megaweb.com>, kennystar@megaweb.com (KENNY MORSE) writes:
> Jaime was kind enough to send me the TIGNOR/WARREN study, and,
> as I thought, their assertion that "If speed limits were raised to more
> realistic levels, would drivers automatically drive 5-10 mph over the
> new speed limit as is commonly believed? The answer is no.  Raising
> the speed by various amounts up to 15 mph has little or no effect
> on speeds over a broad range of road types and speed levels".
> 
> This is misleading BULLSHIT.

No, it's the result of actual measurements.  Just how can such a 
statement be misleading?  

> This is nonsense..... and conclusions WERE drawn in the study that
> standing on a highway over 24 hours at 102 sites in 23 states before and
> one year after a speed change took place, concluded that "Driver 
> compliance with speed limits was poor".
> 
> THAT tells you that no matter where and what the speed limit set,
> people STILL did NOT comply.  

It doesn't say that at all.  And the reason for this is just a few 
sentences further down:  

  "On many streets and highways the speed limit is set 8 to 12 mph below 
  the prevailing 85th-percentile speed."

and a bit later:

  "Many current speed limits coincide with the 30th-percentile speed."

Yes, measurements were made "after a speed change".  But those speed 
changes were not dictated by the folks writing the study.  They were, 
as stated in the preliminary report, the result of "routine speed 
zoning changes".  Some of these changes were to decrease the posted 
limits!  There is absolutely nothing in the report that implies 
that "Driver compliance with speed limits was poor" *on roads where 
the speed limit is near the measured 85th-percentile speed*.  

You have managed to take a report that conclusively argues that speed 
limits are set too low, and which shows *through actual measurements 
of driver behavior* that raising speed limits to realistic 
(85th-percentile) levels would NOT automatically induce drivers to 
drive 10-15 mph above the new limit... and find a SINGLE sentence to 
interpret out of context to bolster your preconceived notions.  

> I do NOT measure THAT they speed....I measure WHY they speed in
> my classes.  Jaime says that my "sample" is biased and doesn't reflect
> anything significant.  That TOO is nonesence (respectfully, Jaime).
> The reasons people go to Traffic School is twofold: 1)To keep the
> driving privledge from being lost and 2)To keep the insurance company
> from finding out about it.

In other words, people go to Traffic School because they've gotten a
speeding ticket... likely more than one.  When I say "your sample is
biased" I mean it isn't representative of the driving public at large
... since the majority of them haven't gotten any tickets recently.  

You know, NOTHING in anything you've written suggests that you've 
asked any of these folks the key question:

  If the speed limit were set to a little above your comfortable speed for
  the road in question, would you still drive at 10 or 15 mph above the 
  new limit?

Why don't you try asking some of your callers that question?  Indeed,
why don't you ask YOURSELF?  If you were to imagine yourself driving
down a lightly-used stretch of freeway, where you were very
comfortable driving, say, 72, and the sign-posted limit was 75... would
you automatically increase your speed to 85 or 90?  As you think of
yourself in that frame of mind, being COMFORTABLE at the speed you're
going... that speed being neither too fast for conditions nor
obviously slower than necessary for conditions...  doesn't it seem as
though there would be no reason to drive much faster?  Why do you
assume that everybody would suddenly be comfortable driving at 80 or
85 if the signs were posted for 70 in areas where the 85th percentile
speed is near 70?  

Why don't you try asking your callers about that, in that way?  ... if 
you aren't afraid to challenge your beliefs, that is. 

	--- Jamie Hanrahan, Kernel Mode Systems, San Diego CA
Internet: jeh@cmkrnl.com (JH645)  CompuServe: 74140,2055  


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