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Re: Daytime running lights



TJNYE@MANSCI.watstar.uwaterloo.ca (Tim Nye) wrote:

->In article <405mb7$1cs@nnrp2.primenet.com> gribble@primenet.com writes:

->>I was asked to repost the following info concerning Daytime Running Lights.

->Actually, in a prior post you claimed:

->	"Of the studies done in countries where DRLs are pretty much the 
->	norm or at least very common, the statistics show that accidents 
->	have gone up, not down, since the use of DRLs began."

->and I asked if you could post the studies which supported this.  

->The study you mention from Norway said:

->	"The total number of multiparty accidents in daylight was not 
->	reduced."

->"not reduced" does not mean "have gone up, not down".  I think you will also

->find that study from Finland and Sweden (which introduced DRLs quite a bit 
->earlier than in Norway) says:

->	"it was found that daylight accidents involving more than one 
->	vehicle were reduced by 10% while daylight accidents between motor 
->	vehicles and unprotected road users were reduced by 15-20%." 

->Funny, this seems to contradict your claim that accidents have increased.  
->Apparently you must have posted the abstracts from the wrong studies.  Could

->you post the studies which support your claim that accident rates go up when

->DRLs are commonplace?

->Thanks,

->Tim


Thanks for taking so many things out of context.  Firstly, you only quoted the
one line about how some accidents were not reduced... why did you ignore the
other info in the abstract??  To wit...

FOUR hypotheses concerning the effects of daytime running
lights are tested. NONE of them was supported. The total number of multiparty
accidents in daylight was NOTreduced. Pedestrian accidents and accidents
during twiligt were NOT reduced. The number of rear-end collisions INCREASED
by about 20%. 

As to the Finland and Sweden Study, you are reading something into it that
does not seem to be there.  That study prefaced it's remarks with the EARLY
results, from other studies of when few cars had DRLs and there was an
apparent reduction.  It was NOT a study of the long term effects on all types
of accidents but was a study trying to find an explanation for the odd
observation that DRLs seemed to reduce the incidence of certain types of
pedestrian accidents.  It was not a study of overall accident rates.

The Norway study appears to be the most recent and most definative and does
not support the claimed value of DRLs.  It also reinforces what someone else
posted about how the use of DRLs was mandated some years ago in one of the
states with the same results, i.e., when DRLs were a novelty and made people
notice them, accidents went down but when the novelty value wore off, the
accident level returned to what it was before.  Interestingly, the same thing
seems to have happened with Busses.  About 20 years ago, some Bus Companies
started putting a single light  one the front of their busses and found that
their accident invovlement seemed to go down.  It was much ballyhooed when
they started using them.  Little was said thought when within 2 years they
stopped using them.  Since one would surmise that in a profit driven
environment they would have continued using them if there continued to be
benefit one can further surmise that once the novelty of the single DRL on the
busses wore off their accident rates went back up.  Of course, no one issues
press releases saying how something doesn't work so those DRLs simply faded
away. 



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