NY Times article - Cycling will kill you!

On Sunday, November 17, 2013 1:44:59 PM UTC-5, Jay Beattie wrote:
On Sunday, November 17, 2013 8:45:36 AM UTC-8, Frank Krygowski wrote:

On Saturday, November 16, 2013 11:16:35 PM UTC-5, Jay Beattie wrote:

One more time with emphasis -- the green boxes are not causally connected to the right hooks. Passing on the right, with or without a bike lane (recall that passing on the right is legal in Oregon), is.

Jay, the people who designed them, promoted them and installed them thought there was certainly a connection. You gave a link to the flyer they distributed, and that flyer states their purpose is to "prevent bicycle/car collisions, especially between drivers turning right and bicyclists going straight." It restates that several more times, using different wording. It seems silly to say there's _no_ effect on behavior.

Given the publicity, why then would cyclists NOT engage in risk compensation, and NOT enter a bike box intersection feeling that they are protected, that they can be less wary? Seems to me they're told they're now OK, and they naturally believe what they've been told.

I think you're using our green boxes to pursue another agenda -- the flogging of facilities, whatever they may be. Some deserve to be flogged, and others don't.

But here you have a design that tripled the specific crash type it was supposed to prevent. You don't think that deserves flogging? What on earth, then, constitutes "failure" in your book?

The specific crash type they were designed to prevent was the type that killed Tracey Sparling -- stopped truck versus stopped bike, both taking off at green light.

Seems you should re-read the pamphlet you gave us in PDF form. Here are the quotes: "The bike box is an intersection safety design to prevent bicycle/car collisions, especially those between drivers turning right and bicyclists going straight." And "The main goal is to prevent collisions between motorists turning right and cyclists going straight." And "Bike boxes increase safety when drivers are making right turns by allowing cyclists to move in front. ... Increase safety by reminding motorists to be alert for cyclists."

None of those say anything about stopped trucks and stopped bikes. They give a strong impression that the bike boxes are to reduce _all_ right hook crashes. But at that, they've failed, since right hooks nearly tripled, as shown by four years of results.

I haven't run across a single person who thinks the green boxes will magically protect them from right hooks while passing moving traffic. Nobody thinks that, except those people populating your make-believe world of deluded cyclists and sinister planning authorities.

Perhaps you haven't run across a person who's told you that. It does not mean that there aren't people who believe it.

For another thing, we have very few people who believe adding green paint will turn our city into Copenhagen.

You probably have very few cyclists, too. PDX will never be Copenhagen...

Don't let too many people hear you say that! You may be lynched by a gang of bohemians! ;-)

... but we have a high enough bicycle modal share to justify looking at options other than pure shared roadways. We also have woefully inadequate roadways for our existing auto traffic, which is at least some reason that advocates are looking at separate facilities.

That makes an interesting puzzle. Is Portland really going to take more pavement space away from the already inadequate roadways, to make separate bike facilities? According to this article
http://bikeportland.org/2013/10/30/c...agnation-96367
bike modal share is way lower than sometimes implied. Second to last for "all trips," in fact, below "Walking" and "Public Transit." Granted, it's nice that it beat out "Other," but I'm having trouble telling what "Other" may be. Skateboards? Pogo sticks?

The whole world is not your village in Ohio. I pass more cyclists in a day than you probably see in a week or month.

You probably do. That's also true of light rail, buses, streetcars and maybe even motor vehicles. You're in a big, very dense city, while I'm in a small, much lower density one. Heck, we hardly have traffic jams.

... some people even call me the Frank Krygowski of Portland.

Cool! Use that power wisely! ;-)

- Frank Krygowski

On Sunday, November 17, 2013 1:58:14 PM UTC-5, Duane wrote:

Lot of infrastructure in Quebec and a lot of cyclists. Seems that there's
a direct relation there.

Of course, and the cause-and-effect relationship goes both ways. If there are no cyclists, there's no political will to cater to cyclists. If there are lots of cyclists, politicians start trying to do anything they can to get their votes.

And I emphasize the "anything" part of that. The projects don't have to make sense. They don't have to make riding safer. They just have to be visible. Few cyclists are competent to judge relative safety of facilities. Watch any door-zone bike lane for proof.

I guess a lot of cyclists must be really dumb as well as being hippies.

Well, a lot are really uneducated about facility design. How many cyclists do you know that actually read the design manuals, read the research papers, enter into detailed discussion of these things?

Not all infrastructure is good and this needs work but it generates more
cyclists.

It's good you were able to type the first nine words of that sentence! But why let the last few excuse terrible, failed designs? Again, we're talking about a design that was promised to reduce right hook crashes. Instead, right hook crashes tripled. Why can't we agree that the design did not work?

- Frank Krygowski

On Sunday, November 17, 2013 2:17:34 PM UTC-5, Dan wrote:
Frank Krygowski writes:

Why not be at the center of the lane anyway? In general, if your speed is the same of the motor vehicles around you, you're more visible and safer at lane center. When the mutual speed is zero at an intersection, that applies at least as much.

Um... because I'd be several car lengths back from the intersection
breathing exhaust fumes (?)

Many times you'll be at the very front. Even if you're not, you don't need to be breathing exhaust fumes; it's not like they're piped directly from the engine to your nose. (In fact, if the breeze is from your left, then your gutter position will give you more exhaust.) The exhaust fume thing is fake.

Stopping at lane center should be normal. It almost totally prevents the crashes that killed Tracey Sparling. And if you see that the motorist behind you wants to turn right, (or if you know an intersection gets lots of right-on-red traffic) you can move a couple feet further left as you glide to a stop, then wave them by on your right. I do this often, and always get a "thank you" wave.


It doesn't take much of a "hole shot" to beat a typical car across an intersection. I do it almost every time, and I'm on Medicare.

Well, if you're in the center of the lane blocking them, it's
not that hard.

No, Dan, I'm not blocking them. I routinely outrun cars for the first 30 feet. The gap between my back wheel and their front bumper increases during that time. Part of it is that I do actually pay attention to the light turning green, something many motorists don't do. But part of it is that most motorists really do accelerate slower than I do from a standing stop.

- Frank Krygowski

On Sunday, November 17, 2013 1:02:37 PM UTC-8, Frank Krygowski wrote:
On Sunday, November 17, 2013 1:44:59 PM UTC-5, Jay Beattie wrote:

On Sunday, November 17, 2013 8:45:36 AM UTC-8, Frank Krygowski wrote:



On Saturday, November 16, 2013 11:16:35 PM UTC-5, Jay Beattie wrote:



One more time with emphasis -- the green boxes are not causally connected to the right hooks. Passing on the right, with or without a bike lane (recall that passing on the right is legal in Oregon), is.



Jay, the people who designed them, promoted them and installed them thought there was certainly a connection. You gave a link to the flyer they distributed, and that flyer states their purpose is to "prevent bicycle/car collisions, especially between drivers turning right and bicyclists going straight." It restates that several more times, using different wording. It seems silly to say there's _no_ effect on behavior.



Given the publicity, why then would cyclists NOT engage in risk compensation, and NOT enter a bike box intersection feeling that they are protected, that they can be less wary? Seems to me they're told they're now OK, and they naturally believe what they've been told.



I think you're using our green boxes to pursue another agenda -- the flogging of facilities, whatever they may be. Some deserve to be flogged, and others don't.



But here you have a design that tripled the specific crash type it was supposed to prevent. You don't think that deserves flogging? What on earth, then, constitutes "failure" in your book?



The specific crash type they were designed to prevent was the type that killed Tracey Sparling -- stopped truck versus stopped bike, both taking off at green light.



Seems you should re-read the pamphlet you gave us in PDF form. Here are the quotes: "The bike box is an intersection safety design to prevent bicycle/car collisions, especially those between drivers turning right and bicyclists going straight." And "The main goal is to prevent collisions between motorists turning right and cyclists going straight." And "Bike boxes increase safety when drivers are making right turns by allowing cyclists to move in front. ... Increase safety by reminding motorists to be alert for cyclists."


FNA, Frank -- seems you should re-read the pamphlet: "When a traf�c signal is yellow or red, enter the bike box from the approaching green bike lane. Stop before the crosswalk. When the light is green, proceed as normal. Be aware of right-turning motorists, especially
while in the green lane in the intersection."

Further:

"WHY ARE BIKE BOXES BEING INSTALLED?
The main goal is to prevent collisions between motorists turning right and cyclists going straight. It’s all about visibility and awareness. At a red light, cyclists are more visible to motorists by being in front of them. At a green light, the green bike lane through the intersection reminds motorists and cyclists to watch for each other."

NOTE the reference to "green bike lane through the intersection" and not the bike box. The box -- as opposed to the green lane -- was intended to prevent conflicts between stopped vehicles. The pamphlet emphasizes that when proceeding thought a green light, cyclists stay in the green bike lane, watching for cars. Again, the box is just for when you're stopped. The green bike lanes existed in some places before the boxes, and near my house, they used to be blue. Green is the new blue. http://tinyurl.com/n3ef6u9

Maybe we're just arguing over terms and you see the entire facility as the "box." Yes, the lane and the box together were intended to lessen collisions in intersections. The boxes have been effective -- the lane has not (at least according to some reports). Until cars understand that cyclists in the lane have the right of way, one could argue that they actually promote collisions.

-- Jay Beattie.









None of those say anything about stopped trucks and stopped bikes. They give a strong impression that the bike boxes are to reduce _all_ right hook crashes. But at that, they've failed, since right hooks nearly tripled, as shown by four years of results.



I haven't run across a single person who thinks the green boxes will magically protect them from right hooks while passing moving traffic. Nobody thinks that, except those people populating your make-believe world of deluded cyclists and sinister planning authorities.



Perhaps you haven't run across a person who's told you that. It does not mean that there aren't people who believe it.

Yes, and there are people who believe in Santa Clause and the immortality of Elvis.



For another thing, we have very few people who believe adding green paint will turn our city into Copenhagen.



You probably have very few cyclists, too. PDX will never be Copenhagen....



Don't let too many people hear you say that! You may be lynched by a gang of bohemians! ;-)



... but we have a high enough bicycle modal share to justify looking at options other than pure shared roadways. We also have woefully inadequate roadways for our existing auto traffic, which is at least some reason that advocates are looking at separate facilities.



That makes an interesting puzzle. Is Portland really going to take more pavement space away from the already inadequate roadways, to make separate bike facilities? According to this article

http://bikeportland.org/2013/10/30/c...agnation-96367

bike modal share is way lower than sometimes implied. Second to last for "all trips," in fact, below "Walking" and "Public Transit." Granted, it's nice that it beat out "Other," but I'm having trouble telling what "Other" may be. Skateboards? Pogo sticks?



The whole world is not your village in Ohio. I pass more cyclists in a day than you probably see in a week or month.



You probably do. That's also true of light rail, buses, streetcars and maybe even motor vehicles. You're in a big, very dense city, while I'm in a small, much lower density one. Heck, we hardly have traffic jams.



... some people even call me the Frank Krygowski of Portland.



Cool! Use that power wisely! ;-)

Frank Krygowski writes:

On Sunday, November 17, 2013 2:17:34 PM UTC-5, Dan wrote:
Frank Krygowski writes:

Why not be at the center of the lane anyway? In general, if your speed is the same of the motor vehicles around you, you're more visible and safer at lane center. When the mutual speed is zero at an intersection, that applies at least as much.

Um... because I'd be several car lengths back from the intersection
breathing exhaust fumes (?)

Many times you'll be at the very front.

I'm dumbfounded.

Even if you're not, you don't need to be breathing exhaust fumes; it's not like they're piped directly from the engine to your nose. (In fact, if the breeze is from your left, then your gutter position will give you more exhaust.) The exhaust fume thing is fake.


http://motoroids.com/assets/Uploads/...aust-fumes.jpg

Anyway, "breathing exhaust fumes" is not just a literal expression.
(If I was really too concerned about it I'd have to wear a respirator,
wouldn't I.) It's a concise way of saying engulfed in the cager scene -
constrained by the car in front of me, in the path of the car behind,
and the likely scapegoat of ire from any further back and wondering
what the holdup is (doesn't matter that the holdup is actually all the
motor vehicles clogging the infrastructure).

Stopping at lane center should be normal. It almost totally prevents the crashes that killed Tracey Sparling. And if you see that the motorist behind you wants to turn right, (or if you know an intersection gets lots of right-on-red traffic) you can move a couple feet further left as you glide to a stop, then wave them by on your right. I do this often, and always get a "thank you" wave.


If I do move left to allow right-turners to the inside, I usually
move to the extreme left of the lane, and this typically as I filter
to the front, seeing the right turn signal(s) at the front of the
queue. When the right-turners are done I wheel back over to the
right.

Where I ride there are no bike boxes putting me ahead of the cars,
so moving left at all isn't even necessary if the lead car wants to
turn right - only if cars behind him want to squeeze by on his right.
Wherever I position myself, as long as I leave them ample space to
execute their turn, eye contact and a stance that is obviously not
going anywhere (hands off the bars, for example) usually suffices -
sometimes with a nod. Rarely do I have to actually direct traffic;
and when I do, action is sufficient acknowledgement - I don't need
social niceties, just decent, reasonable social interaction.

Avoiding the right-hook on fresh green is my problem. It's the
motorist's responsibility to yield, but it's my problem if they
don't (under any circumstances, fresh or stale). It's as simple
as that. As with taking the lane in general, I don't consider it
reasonable to block straight ahead traffic on the *assumption* that
someone will fail to accommodate my right-of-way as I ride as far
right as proacticable. I'm just aware that it may happen and take
that into account to the extent it matters at various points. *If*
there is reason to believe my right-of-way is *likely* to be violated,
that is reason to do something different, like taking the lane - but
not just as assumptive default.

You're correct that this right-hook problem is solved by not riding
to the right of other traffic that can turn right; I just don't
take it to the extreme of refusing to share the straight ahead
lane because somebody *might* pull a boner. The reasonable way to
proceed is from the assumption that people will do the right thing,
but situationally aware and prepared to deal with the possibility
and probability that they will not.

YMMV, and I am totally okay with you, Aunt Bea... anyone who feels
they need the entire lane; just don't label me a cowardly gutter
bunny. I'm not. I just pick my battles based on different values
and objectives.


It doesn't take much of a "hole shot" to beat a typical car across an intersection. I do it almost every time, and I'm on Medicare.

Well, if you're in the center of the lane blocking them, it's
not that hard.

No, Dan, I'm not blocking them. I routinely outrun cars for the first 30 feet. The gap between my back wheel and their front bumper increases during that time.


(I find it interesting that you are watching *behind* you as you
accelerate into intersections. Yes, I know you have that dental
mirror on your glasses and it's all part of situational awareness
- but still... curious.)

Vehicles *should* spread out as they start moving and gain speed.
Just because the car behind doesn't tailgate you doesn't mean you
aren't impeding them.

And nothing wrong with that - give my regards to Aunt Bea and the
gang down at the Purple Pants Shop, and more power to you, brother.

Part of it is that I do actually pay attention to the light turning green, something many motorists don't do. But part of it is that most motorists really do accelerate slower than I do from a standing stop.


Either motorists are quicker off the line where I ride, or I am slower
out of the hole than you are, or both (heaven knows you get a lot more
practice with standing stops ;-); but if I don't fool around, I can get
going and over to the right before the driver(s) immediately behind have
a chance to get too ****ed off, though *still*, somebody farther back in
the queue, who is just ****ed off about *something*, will naturally
blame me for *all* their rush hour frustration, and let me know this in
no uncertain terms as they pass. As you said, "They dislike us simply
because we are there" (especially, though far from exclusively, when
"there" is in their way).

On Monday, November 18, 2013 3:52:14 PM UTC-5, Stephen Bauman wrote:
On Sat, 16 Nov 2013 08:35:42 -0800, Frank Krygowski wrote:



snip



On Saturday, November 16, 2013 10:20:48 AM UTC-5, Stephen Bauman wrote:



What's the source of your information?



Here's a link to a report evaluating Portland's bike box "experiment."



http://nacto.org/wp-content/uploads/...of-Bike-Boxes-

at-

Signalized-Intersections-2010.pdf



That's a link to a 2010 draft report. First, if you read it through,

you'll see it has much to do with _perceived_ safety, and judgments by

respondents looking at photos of installations, etc. It emphasizes that

much more heavily than the observations from cameras. (Even so, it

notes that only about 5% of bicyclists use the bike boxes as intended -

that is, to get literally in front of the cars.)



My sources of information were given upthread. Here they are again:

http://www.portlandmercury.com/Blogt...12/10/16/city-

finds-bike-boxes-may-actually-increase-crashes



and



http://www.portlandmercury.com/image...16/1350403953-

bike_box_letter_merc.pdf





Thank you for the links and indulging in my laziness in not following all

your other posts.



When it came to actually decreasing crashes, it certainly seems the

design failed.





You may be a bit hasty in reaching a judgment based solely on the raw

data.



The quoted newspaper blog noted that only 4 of the 11 test sites
experienced an increase in right hook crashes, although total right hook
crash count increased. One could also state that bike boxes were
effective in 64% of the installations. It's a question of whether the
glass is half full or half empty.

Well, if 7 of 11 installations observed no change, or only a statistically insignificant decrease, then one would _not_ say that the bike boxes were effective at those intersections. IIRC, at the four worst intersections, crashes roughly quadrupled, leading to an overall near-tripling of right hooks.

However, the source document that you referenced some important
information that both the blogger and you ignored.

The first item is minor. If you look at the actual data contained in the
source document, 5 of the 11 intersections experience an increase in
right hook crashes. I note this because it is a measure of how carefully
the newspaper blogger examined the report.

The report contains two caveats that are stated on the bottom of the
first page:

"Bicycle use and volumes increased significantly since the treatments
were installed.

Police investigation and reporting practices have changed since the
treatments were installed resulting in a higher rate of reporting for
bicycle involved crashes."

The second caveat calls into question the validity of using actual police
reports for comparing before and after right hook collisions at these
intersections. Even worse, there is no obvious quantitative correction to
correct for the difference in before and after reporting standards.

The first caveat should be obvious. If more bicycles passed through the
treated intersections, then more right hook collisions would be expected.
Another caveat that was not mentioned is that if more vehicles making
right turns at the treated intersections should also result in more right
hook collisions.

The table that recorded the number of right hook collisions also noted
that ridership on the Willametter River bridges increased 50% and all
crashes reported by the police increased by 55%. That's quite a change
and should be factored in. What's important is the differences in bike
and vehicle right turn volumes at these 11 intersections.

Up to now, I'd gotten no indication that the bike traffic volumes had nearly tripled at the intersections in question - as did the right hook crashes.


Fortunately, there is before and after survey data for most of these
intersections. It's contained in Table 1 of the reference I cited. You
will be pleased to know that the final report was issued and is available
at:

http://otrec.us/project/227

Thanks. I'll download it and read it.

The survey data shows: bikes before, bikes after, vehicle right hand
turns before and vehicle right turns after. There is no ambiguity for
determining these parameters, unlike conflict detection. There is
complete data for only 9 of the 11 treated intersections. The
instrumentation did not work for one of the intersections and was
incomplete for another.

A reasonable methodology for compensating for differences in bicycle and
vehicle right turns is to prorate the actual before right hook crashes by
the ratios for the after to before for the changes both number of
bicycles and number of right turning vehicles. The result would be the
expected value for right hook crashes, if there were not intersection
treatment. This number would then be compared to the actual number of
right hook crashes for the treated intersection. This comparison would
try to eliminate the differences due to increased traffic volumes.
An example of the calculation is as follows:

the number of before and after right hook crashes for the intersection of
SW 3rd & Madison are 4 and 9 respectively. The before and after cyclist
counts were 314 and 611 respectively. The before and after counts for
vehicles turning right were 101 and 117 respectively. Therefore one would
reasonably expect the after count for the number of right hook crashes to
be:
4 x (611/314) x (117/101) = 9.02.
if there were no treatment.

The actual count was 9, meaning the bike box had negligible effect on the
number of right hook crashes at this intersection - despite a 125%
increase in the raw numbers.

If this calculation were carried out for the 9 intersections for which
there was complete data, the total expected number of right hook crashes
would be 37.98. The actual total count was 32, meaning the bike box
treatment prevented 5.98 right hook crashes. The two missing
intersections did not experience any right hook crashes, so not including
them did not change this result.

I would not bet the farm on these results. There are too few data points.
That's what the authors of the draft study stated. The blog author
qualified the supposition that the treatments increased crashes by using
the subjunctive voice. Comparing raw data from dissimilar experiments has
its perils.

I'd certainly agree on "not betting the farm." In fact, if the experiment is (as claimed) to test whether bike boxes reduce right hook crashes, there's a big confounding factor. It's become clear to me since this discussion started that with the installation of bike boxes, it also became illegal to do right turns on red at those intersections. ISTM that the proper test would have been to first impose "no turn on red" and gather data; then afterward, install a bike box and see if there is a reduction beyond that from "no turn on red." It seems both modifications are being tested simultaneously, and that may give the bike boxes more credit than they are due. (A "no turn on red," if enforced, should reduce right hooks even at the beginning of a green light phase.)

I'll read the full report. I'm sure many others here will as well. ;-)

- Frank Krygowski

Frank Krygowski writes:


snip


I'd certainly agree on "not betting the farm." In fact, if the experiment is (as claimed) to test whether bike boxes reduce right hook crashes, there's a big confounding factor. It's become clear to me since this discussion started that with the installation of bike boxes, it also became illegal to do right turns on red at those intersections. ISTM that the proper test would have been to first impose "no turn on red" and gather data; then afterward, install a bike box and see if there is a reduction beyond that from "no turn on red." It seems both modifications are being tested simultaneously, and that may give the bike boxes more credit than they are due. (A "no turn on red," if enforced, should reduce right hooks even at the beginning of a green light phase.)


How does that work?? Are you talking about reducing the right-
hooks on (blithe) red-light-blowing, scofflaw bicyclists?

ISTM that no turn on red only makes cagers more anxious to jump
at the fresh green, and leaves more right-turners for the green
cycle when bicyclists are riding straight through.

snip

On 11-17-2013, 13:23, Dan wrote: It's as you've said - it takes more
than some paint. Portland is
doing more than laying down paint. It's happening there. I know

Portland is one of the places that has a pedal-powered moving company.

--
Wes Groleau

In any formula, constants (especially those obtained
from handbooks) are to be treated as variables.

Wes Groleau wrote:
On 11-17-2013, 13:23, Dan wrote: It's as you've said - it takes more
than some paint. Portland is
doing more than laying down paint. It's happening there. I know

Portland is one of the places that has a pedal-powered moving company.

http://www.demenagementmyette.ca/home/

--
duane

On Mon, 18 Nov 2013 20:08:59 -0800 (PST), Frank Krygowski
wrote:

On Monday, November 18, 2013 3:52:14 PM UTC-5, Stephen Bauman wrote:
On Sat, 16 Nov 2013 08:35:42 -0800, Frank Krygowski wrote:



snip



On Saturday, November 16, 2013 10:20:48 AM UTC-5, Stephen Bauman wrote:



What's the source of your information?



Here's a link to a report evaluating Portland's bike box "experiment."



http://nacto.org/wp-content/uploads/...of-Bike-Boxes-

at-

Signalized-Intersections-2010.pdf



That's a link to a 2010 draft report. First, if you read it through,

you'll see it has much to do with _perceived_ safety, and judgments by

respondents looking at photos of installations, etc. It emphasizes that

much more heavily than the observations from cameras. (Even so, it

notes that only about 5% of bicyclists use the bike boxes as intended -

that is, to get literally in front of the cars.)



My sources of information were given upthread. Here they are again:

http://www.portlandmercury.com/Blogt...12/10/16/city-

finds-bike-boxes-may-actually-increase-crashes



and



http://www.portlandmercury.com/image...16/1350403953-

bike_box_letter_merc.pdf





Thank you for the links and indulging in my laziness in not following all

your other posts.



When it came to actually decreasing crashes, it certainly seems the

design failed.





You may be a bit hasty in reaching a judgment based solely on the raw

data.



The quoted newspaper blog noted that only 4 of the 11 test sites
experienced an increase in right hook crashes, although total right hook
crash count increased. One could also state that bike boxes were
effective in 64% of the installations. It's a question of whether the
glass is half full or half empty.

Well, if 7 of 11 installations observed no change, or only a statistically insignificant decrease, then one would _not_ say that the bike boxes were effective at those intersections. IIRC, at the four worst intersections, crashes roughly quadrupled, leading to an overall near-tripling of right hooks.

However, the source document that you referenced some important
information that both the blogger and you ignored.

The first item is minor. If you look at the actual data contained in the
source document, 5 of the 11 intersections experience an increase in
right hook crashes. I note this because it is a measure of how carefully
the newspaper blogger examined the report.

The report contains two caveats that are stated on the bottom of the
first page:

"Bicycle use and volumes increased significantly since the treatments
were installed.

Police investigation and reporting practices have changed since the
treatments were installed resulting in a higher rate of reporting for
bicycle involved crashes."

The second caveat calls into question the validity of using actual police
reports for comparing before and after right hook collisions at these
intersections. Even worse, there is no obvious quantitative correction to
correct for the difference in before and after reporting standards.

The first caveat should be obvious. If more bicycles passed through the
treated intersections, then more right hook collisions would be expected.
Another caveat that was not mentioned is that if more vehicles making
right turns at the treated intersections should also result in more right
hook collisions.

The table that recorded the number of right hook collisions also noted
that ridership on the Willametter River bridges increased 50% and all
crashes reported by the police increased by 55%. That's quite a change
and should be factored in. What's important is the differences in bike
and vehicle right turn volumes at these 11 intersections.

Up to now, I'd gotten no indication that the bike traffic volumes had nearly tripled at the intersections in question - as did the right hook crashes.


Fortunately, there is before and after survey data for most of these
intersections. It's contained in Table 1 of the reference I cited. You
will be pleased to know that the final report was issued and is available
at:

http://otrec.us/project/227

Thanks. I'll download it and read it.

The survey data shows: bikes before, bikes after, vehicle right hand
turns before and vehicle right turns after. There is no ambiguity for
determining these parameters, unlike conflict detection. There is
complete data for only 9 of the 11 treated intersections. The
instrumentation did not work for one of the intersections and was
incomplete for another.

A reasonable methodology for compensating for differences in bicycle and
vehicle right turns is to prorate the actual before right hook crashes by
the ratios for the after to before for the changes both number of
bicycles and number of right turning vehicles. The result would be the
expected value for right hook crashes, if there were not intersection
treatment. This number would then be compared to the actual number of
right hook crashes for the treated intersection. This comparison would
try to eliminate the differences due to increased traffic volumes.
An example of the calculation is as follows:

the number of before and after right hook crashes for the intersection of
SW 3rd & Madison are 4 and 9 respectively. The before and after cyclist
counts were 314 and 611 respectively. The before and after counts for
vehicles turning right were 101 and 117 respectively. Therefore one would
reasonably expect the after count for the number of right hook crashes to
be:
4 x (611/314) x (117/101) = 9.02.
if there were no treatment.

The actual count was 9, meaning the bike box had negligible effect on the
number of right hook crashes at this intersection - despite a 125%
increase in the raw numbers.

If this calculation were carried out for the 9 intersections for which
there was complete data, the total expected number of right hook crashes
would be 37.98. The actual total count was 32, meaning the bike box
treatment prevented 5.98 right hook crashes. The two missing
intersections did not experience any right hook crashes, so not including
them did not change this result.

I would not bet the farm on these results. There are too few data points.
That's what the authors of the draft study stated. The blog author
qualified the supposition that the treatments increased crashes by using
the subjunctive voice. Comparing raw data from dissimilar experiments has
its perils.

I'd certainly agree on "not betting the farm." In fact, if the experiment is (as claimed) to test whether bike boxes reduce right hook crashes, there's a big confounding factor. It's become clear to me since this discussion started that with the installation of bike boxes, it also became illegal to do right turns on red at those intersections. ISTM that the proper test would have been to first impose "no turn on red" and gather data; then afterward, install a bike box and see if there is a reduction beyond that from "no turn on red." It seems both modifications are being tested simultaneously, and that may give the bike boxes more credit than they are due. (A "no turn on red," if enforced, should reduce right hooks even at the beginning of a green light phase.)

I'll read the full report. I'm sure many others here will as well. ;-)

- Frank Krygowski

Perhaps they should do what some prefectures are doing here. They have
"motorcycle Boxes". At a stop light you have a "stop" line painted
across the Road and some 12 - 15 feet behind that is another line,
wider than the stop line and with the words "Motorcycle", and usually
a little drawing of a motorcycle. Cars are to stop at the first
(Motorcycle) line and motorcycles are to stop at the second (stop)
line. That way the motorcycles get a head start before the cars turn
:-)

It works too, the cars dutifully stop before the wide line and the
motorcycles worm their way down into their box. when the light turns
green (well, actually a second before) it looks like the start of the
Le Mans race :-)
--
Cheers,

John B.