Bicycle DRL Study. 30%-50% Crash Reduction

On 7/12/2015 11:42 PM, John B. Slocomb wrote:
On Sun, 12 Jul 2015 22:21:38 +0100, Phil W Lee
wrote:

sms considered Sat, 11 Jul 2015 18:49:58
-0700 the perfect time to write:

On 7/11/2015 5:25 PM, John B. Slocomb wrote:
rOn Sat, 11 Jul 2015 07:57:40 -0700, sms
wrote:

I know how some people dislike any statements that are based on actual
data, but the data is pretty clear.

There is one case-controlled study on bicycle DRLs.

From OECD, International Transport Forum (2013), Cycling, Health and
Safety
https://books.google.com.au/books?id=LvthAgAAQBAJ&pg=PA168&hl=en#v=onepage&q&f =false:
"The safety effect of daytime running lights on bicycles was tested in a
Danish study in 2005 (Madsen 2006). Nearly 2,000 cyclists in the town of
Odense used the new induction lights (?ashing type) for one year with,
while 2,000 others continued with ordinary bike lights, which were only
switched on during dark hours. The accident frequencies of the two
groups (based on self-reported accidents) were then compared and analysed.

The main result was that use of daytime running lights was associated
with a reduction of the number of crashes by more than 30%. The number
of related crashes (crashes in daylight and with a counterpart)
decreased by 50% approximately. Both results are statistically
signi?cant. There are indications that the study may have not controlled
for all factors - for instance it is unclear to what extent the control
group’s crashes included single vehicle crashes (this type of crash is
hardly in?uenced use of induction lights). Also, the study makes no
?nding as to the safety effect of ?ashing versus steady lights."

As you can see, the data on bicycle DRLs is actually much more
compelling than the data on vehicle DRLs! And they weren't creating
bogus studies or intentionally misinterpreting data as one organization
we know of is so fond of doing!

But the reduction in crashes is not the only benefit of DRLs. The other
benefit is how bicycle DRLs shape driver behavior by making cyclists
much more conspicuous in the daytime.

Strange data. On one hand you say that "nearly 2,000 riders..." and
compare that with "while 2000 others". Based on your statement it
wasn't really comparing apples to apples.

That was a direct quote from the article, it wasn't "my statement." But
are you really basing your position on the fact that "nearly 2000" does
not exactly equal "2000 others." The results were so overwhelming that
such a slight difference is immaterial.

I'm sure our friend from Ohio doesn't like the fact that this study
proved the effectiveness of DRLs for bicycles but it'd be very difficult
for anyone to dispute the results of this study.

The bottom line is that flashing DRLs work, and _no_ study has
contradicted this one after ten years.

The reason that all the light manufacturers have added flash mode to
lights may be related to this ten year old study. And while I'm certain
that some people will be demanding that more studies need to be
performed the fact is that you're just not going to see anyone spending
money on studies trying to disprove something that everyone knows is
true. Frank is like the 3% of scientists that claim to not believe in
climate change, and even those 3% don't actually believe what they are
saying, they say it because their handlers demand that they say it.

The major point which (probably intentionally) miss, is that the group
of riders using the flashing DRLs is not random, but self-selecting,
as people have to volunteer to take part in such a study.
So it's pretty obvious that the ones who are so paranoid that they'd
fit such lights are going to be less accident prone when compared to
people who are less worried about safety.

So all the study (in common with other similar studies into other
"safety" equipment) shows us is that safety conscious people have
fewer accidents.
Well, gosh, darn, and all that - I don't need a research grant and PHD
thesis to tell me that!

The same set of people would still display a similar reduced number of
accidents with or without whatever "safety" equipment you choose to
add to their cycles.

Look! You have to stop this!

Logic has no place in this discussion!

You're prime proof of this. Phil is wrong of course. Read the study.