On 2/10/2018 5:22 PM, Tim McNamara wrote:
On Thu, 8 Feb 2018 20:12:26 -0500, Frank Krygowski
wrote:
On 2/8/2018 6:13 PM, Tim McNamara wrote:

How are most cyclists injured or killed in accidents? They are
struck from behind by an overtaking motor vehicle.

Sorry, that's not true. See
https://safety.fhwa.dot.gov/PED_BIKE...f/swless04.pdf

snip

11. The most frequent parallel-path crashes were motorist turn/merge
into bicyclist’s path (12.2 percent), motorist overtaking the
bicyclist (8.6 percent), and bicyclist turn/merge into motorist’s path
(7.3 percent).

Do you know if the first type were exclusively drivers and cyclists
traveling in opposite drections? Or does this include situations where
the driver had passed the cyclist and then turned, cutting the cyclist
off? I would include that scenario in my original statement as they
were struck by a vehicle coming from behind. Not that it would be
likely to move that into the majority. Perhaps my information is out of
date, past research had indicated being struck by a vehicle traveling in
the same direction caused more fatalities.

The most frequent crossing path crashes were motorist failed to yield
to bicyclist (21.7 percent), bicyclist failed to yield at an
intersection (16.8 percent), and bicyclist failed to yield midblock
(11.8 percent).

In what scenario does a vehicle turning or entering the road in the
middle of the block have the right of way?

The PDF has illustrative diagrams of several common crash types.

These six individual crash types accounted for almost 80 percent of
all bicycle-motor vehicle crashes."

What are the other 20+%? Bicycists hitting parked cars?

Every examination of crash types I've read always had a sizeable "other"
category. I've assumed this is because many bicyclists find very
creative ways to get in trouble.

So motorist overtaking were just 8.6 percent of the total. And I'd bet
that a majority of those were of two types: Totally Unlit cyclists at
night, which legal lighting would prevent; and "I think I can squeeze
by" events, which would have been averted by lane control by the
cyclist.

I strongly suspect that 8.6% is a gross underestimate and that the real
number is at least double that. It doesn't pass the smell test.

IIRC, various studies have given different percentages to the relative
crash types.

This one from North Carolina
http://www.pedbikeinfo.org/pbcat_nc/...types08-12.pdf
says hits from behind are about 17%.

An Orlando study ("Orlando Area Bicyclist Crash Study:
A Role-Based Approach to Crash Countermeasures") says motorist
overtaking accounted for 8.2%.

Carol Tan's "Crash Type Manual"
https://www.fhwa.dot.gov/publication...pedbike/96104/
lists five sub-categories of crashes caused by "motorist overtaking."
They total 8.6%, but maybe that's using the same data as the other study
I linked.

The Kenneth Cross study from the 1970s said "motorist collided with rear
of cyclist" comprised 4.17% of crashes. It's at
http://www.johnforester.com/Articles/Safety/Cross01.htm

Whatever the percentage, it seems hits-from-behind are a pretty small
percentage of crash types. And it's been noted that many of those that
do occur are rural, unlit cyclists riding at night.

Now granted, when it does happen, it's a very bad thing. It's
responsible for a disproportionate number of fatalities - but again, not
"most" of fatalities, IIRC.

It's a crash type that is excessively feared. There are more important
things to watch out for.

--
- Frank Krygowski