On Sunday, 8 September 2019 20:00:33 UTC-4, Frank Krygowski wrote:
On 9/8/2019 6:24 PM, Steve Weeks wrote:
On Friday, August 30, 2019 at 3:09:00 PM UTC-5, pH wrote:

There was an article in the Santa Cruz Sentinel back in May about a cyclist killed around the Davenport area. There was *never* a follow up about who it was or the circumstances around the death--I even called the local radio station to ask that their news department please follow up on it and give us further information as it became available. Nada thus far.

That second fatality involved the cyclist being struck by a car going in the same direction, ie: "struck from behind".

The League of American Bicyclists had a project going on a few years ago called "Every Bicyclist Counts" (https://bikeleague.org/content/why-e...fatal-crashes). It was an imperfect study, for reasons enumerated in the report, but it had some interesting findings. The most important (to me) was that a third of the bicycle fatalities were the result of the cyclist being "struck from behind".

Now, since this is such a common mode of death for cyclists, it would seem reasonable to try to provide the cyclist with some form of defense. To my way of thinking, this is a rear-view mirror. Of course, the presence or absence of a rear-view mirror wasn't even mentioned in the League's study, and this information is apparently not one of the data collected when a cycling death is investigated.

I just got back from an organized ride (the 50th annual Harmon Hundred) and I noticed that fewer than 10% of the riders had mirrors. It would be interesting to study the correlation (if any) between mirror use and "rear-impact" fatalities. I hypothesize that one exists and it is negative. But without data...
I always ride with a mirror on the street; it can't hurt.

I wouldn't call hits from behind "such a common mode of death for
cyclists" because _all_ cycling deaths are tremendously rare. Other data
shows there are well over ten million miles ridden per cycling fatality.
And as John frequently points out, half of cyclist fatalities are judged
to be the fault of the cyclist. Year after year, data shows a quarter of
fatally injured cyclists had been drinking. So it seems like, roughly
speaking, if you obey the traffic laws and don't ride drunk, you can
probably ride 30 or 40 million miles before getting killed on your bike.
That would take you quite a while - perhaps 4000 years of riding.

Also, other data has shown that the usual hit-from-behind deaths happen
on rural roads, to unlit night cyclists. The useless LAB used that study
as propaganda to call for "protected" bike lanes in cities - an "apples
and oranges" difference that they used to plead for more luxurious
orange crates.

Having said that, I almost always use a mirror when riding. I don't
think of it as a lifesaving tool. I think of it as a tool that allows me
to negotiate traffic better (like timing my merge into a left turn lane)
and to better keep track of my riding partners.

(Speaking of that: I make my own eyeglass mirrors and have a mirror
ready on every bike. But I need to make one more, for my kayak. When
paddling I'm usually ahead of my wife, and it would help me keep track
of her so I don't get too far ahead.)


--
- Frank Krygowski

When 1/3 of so called accidents are "Struck from behind" cases then those are not rare for that demographic. That's 33.3...% of the "accidents". That's no matter how rare bicycle "accidents" are in general it's still 1/3 of them.

Cheers