Soil_Sampler

https://www.velonews.com/article/7447...ing-the-victim

shatdow

Little more descriptive title maybe?

genec

One has to wonder about the biases of the data used for the Cross Fisher studies that have been the basis for Effective Cycling et. al..

I understand that the Cross studies were based on reading police reports... if these reports were heavily biased, then that could have tilted the outcome of the studies.

I-Like-To-Bike

I long ago stopped "wondering" about the usefulness of conclusions drawn by a grossly biased self-proclaimed expert who cherry picked such biased data in order to promote his own agenda.

bikingshearer 

Is there anything that the A&S crowd can't turn into a referendum on John Forester? For crying out loud, people, there are other things going on in the world. Even in the bicycling world. Even in the bicycling advocacy world. Time to move on, don't'cha think?

genec

Well when you consider either he or his ideas represented by others tend to dominate certain sectors of cycling advocacy... the answer is clearly no.

But the data that much of his work is based upon is from studies made in the 70s gathered from police reports that were most likely biased. and as ILTB points out, the data was probably further cherry picked to meet certain hypothesis.

Meanwhile, other places have shown that cyclists can well get along well in society with a nice mix of political support and facilities, such as exist in many European cultures and even here in Portland Or. (now with a 6% model share). Yet that very reality is denied by those "schooled" in Forester's model.

So on one hand we have one concept probably fueled by biased data. On the other, we have clearly observable results. And because of this dichotomy, this vast rift exists in the cycling community.

invisiblehand

I doubt that only the Ken Cross gathered data has a bias to it ... on this or the other side of the Atlantic.

The Human Car

The idea of studies like Cross Fisher is to reshuffle the police reports according to different criteria. Police reports are primarily concerned at documenting who is at fault and why. The Cross Fisher study was about identifying crash types or categorizing the movements involved and unlike police reports the Cross Fisher study was reviewed. I seriously doubt one can accuse the study of bias of incorrectly identifying wrong way cycling as right way cycling or any such category errors. Where the bias and errors come in is in drawing conclusions from this data. As ILTB likes to subliminaly suggest without exposure rates we cannot really say what movement is more dangerous then another movement.

As an example of a conclusion error; since most cycling crashes happen to sober cyclists riding on 25mph roads and hardly any crashes happen to drunk cyclists on 65+mph roads, so therefore riding drunk on the expressway must be the safest way to ride.

What we do have is a list of the relative dangers of car/bike interactions, logically we could spin off a couple of alternate universes where we would be teaching how to ride safe while riding against traffic or how to ride safe while cycling on the sidewalk. The reasons why we did not choose those routes should be self evident.

So now what is in question is the methodology employed to mitigate the dangers of car/bike interactions, which is based on our experience, observations and assumptions. In short safe cycling is based on our bias but only because nothing better is available.

I-Like-To-Bike

Exactly right. The fatal flaw of such so-called risk analysis has all along been drawing conclusions based more on the analyzer's bias than on the actual available data. I didn't think I was all that subliminal in previously pointing out the fatal flaw of drawing any conclusion about relative risk of various scenarios without considering exposure rates and accident severity, both factors completely ignored by Forester, et al. in their bogus "crash rate" analysis schemes.

Even safer must be drunk riding the wrong way in the traffic lanes of the expressway without lights at midnight. I'm willing to bet "statistics" prove there is a ZERO CRASH RATE for such a safe cycling technique.

genec

But even in the Cross Fisher studies the information was based on what police had gathered from witnesses.. if the only witness is a motorist and dead cyclist, how accurate is the data contained in the police report... sure the motorist said the cyclist was riding the wrong way... or swerved or came flying out of the intersection... and that is what the police wrote... and that is what Cross Fisher cataloged, but if the only witness was lying in the first place... the resultant study is going to be skewed.

Velo news even reported that there was a bias of police tending to question motorists while ignoring live cyclists... again if the motorist is seeking to cover their behind, the resulting report will tend to convey the data the motorist wants the police to believe, regardless of the truth.

One can be as objective as possible while compiling the data, but if the data is based on bias and lies, then the outcome will tend to reflect that input. (Garbage in ----> Garbage out)

I am sure the review process did verify that Cross and Fisher were objective about their methods of cataloging the data... but again, if the data were flawed...

invisiblehand

With regards to accident studies in general, I would be pretty surprised if there was wide-spread general disregard for the truth among the police. That is, I believe that their is an anti-cycling bias but that it is probably more of a subconscious bias rather than an active one. Roughly speaking, these accident studies produce results that are in the same ballpark of each other. Now there is a huge identification issue going on, but if this bias is so important small changes in police attitudes should make a big difference in the accident studies.

One can also think about the bias itself and what it means for the analysis and model fitting. My guess is that drivers probably stretch the truth more than make-up fairy tales. For example, a driver would probably say that the cyclist failed to stop at the light/intersection than completely fabricate a story where the cyclist was riding on the wrong side of the street.

Anyway, this doesn't change the fact that exposure in many of these studies is unobserved ... although I have seen a reference to one that did ... such that the probabilities/rates that we would want to know are unknown.

I still don't know why, however, one would think that U.S. accident data is so terrible such that zero inferences can be made while the data about the glorious and safe cycling in Europe is unaffected. If anything, it would seem as if a European driver has a greater incentive to lie -- since they have increased liability -- after an accident than a US/British driver.

The Human Car

Ok let's lets say that a lot of crashes were falsely categorized as the cyclists failing to yield the right of way at a stop sign when it really was the motorists who failed to yield the right of way. But since the study does have a significant showing of motorist failing to yield about the only conclusion from this study we could hope to change would be that we could make an assertion that it is safe for cyclists to blow stop signs as it was almost always the motorists fault for failing to yield. While that would be a fun fact to throw around, in practicality it really would not do us much good.

And again what would change and be the implication that all/most wrong way crashes are misclassified and should be be classified as same direction crashes. That would then assert that wrong way cycling is the safest.

In other words what specific outcome of this study that we should be highly suspicious of and how is that based on some logic of misclassification? Bias maybe but without any evidence the bias has altered the outcome we really cannot make a case that a bias has influenced the outcome.

It is sort of like accusing a person of a particular race of having a bias in hiring practices but if the ratio of race hired is where we would expect it then what is the evidence of a bias other then it "could" exist.

Almost all official stuff in regards to bicycling stinks in someway, but that does not mean we should throw it all out and not look into it in some detail to see what we can and cannot assert from it.

genec

Agreed... I do however think that perhaps we can question some of the safety issues that have resulted from such reports...

Are bike lanes as bad as has been suggested for instance...

What really is the frequency of overtaking collisions as another.

Perhaps cycling is not quit as safe as some portray it... and what can be done to increase said safety.

All these are issues that bear further examination... and to depend on the 30+ year old data from a study that compiled questionable data is at the very least something that we should stand up and confront.

invisiblehand

Although once you leave the world of JF's website there are plenty of other studies -- accident tabulations -- which produce results where one could draw similar conclusions. The 30+ year-old criticism is a small one if one can simply replace the data set with one from a more recent time.

And I guess we should be questioning the results of the "European model" with the same skeptical eye ...

The Human Car

Genec, As far as I am aware reports do not suggest bike lanes are bad, it is JF in particular that makes an argument based on lawful cyclists behavior bike lanes should have a slight decrease in safety. And I counter that with an argument without bike lanes we must also include unlawful cyclists (wrong way and sidewalk riding) so we should see a slight decrease in safety without bike lanes as well.

I agree we need a new study and it is something I am working locally on. But as far as getting data that would support that VC is safer then bike facilities how the heck would one determine if a cyclist is VC or not? Use JF criteria that there is only 3-4 VCs in this forum? Make all VC wear a yellow arm band so we know for sure? Use the criteria established on this forum that if a cyclists was in an accident then they were not riding in the proper VC fashion? It seems to me we are a long way off from "proving" the safety of VC.

The other problem with the 30 year data is the assertion that intersections are the most dangerous for us. According to FARS intersections account for only a 1/3 of our fatalities. There may be a reason to be afraid of same directional traffic after all.

genec

Agreed... my only connection to BL and JF is that he and his followers often use the Cross study as a basis for their thinking which includes the damnation of BL.


I tend to agree... I think it is experience not a particular riding style that makes certain cyclists safer. I know I do use VC techniques when appropriate, but I also use BL and even ninja cycling and sidewalk cycling where it makes me the safest.

I tend to agree.

genec

We should indeed... but bear in mind that the "European model" has at least the success of increasing ridership... there is nothing else that does that.

I-Like-To-Bike

That is EXACTLY the criteria used by Forester to establish his fabricated "safety record" for his chimeric band of "likely" Vehicular Cyclists. Everybody is a Vehicular Cyclist for his statistical purposes UNTIL they have an accident/collision. Then they join the other group -the non-VC of incompetent, lawless rube riffraff.

Even more so this was the model used by HH with his claims that accidents for vehicular cyclists with the right attitude were as unlikely as being hit by a meteor. Anyone hit by a motor vehicle musta been doing something wrong!

invisiblehand

Sure thing Gene. And I don't mean to "poo-poo" facilities either. There is plenty of uncertainty to go around.

genec

OK fair enough, no study has been done... that I am aware of (I deserved that).

But in the meantime, no where has any other form of cycling advocacy (or promotion or whatever you want to call it) been able to increase the numbers of cyclists. Look at Portland for instance and their insistence that they now have a mode share of some 6%... no where else in the US is anywhere near as high. One has to ask... what makes the difference.

Is it the fees and restrictions on motoring as John Forester states... Well there are no such fees and restrictions in Portland. Is it the geography of the area... matched in other places. So what is making the difference???

The Human Car

Exactly, it all comes down to being aware of the hazards and taking steps to mitigate them and the more options you have at your disposal the better.

The Human Car

I thought you would like that bit.

I-Like-To-Bike

It is not a question of liking it, but recognizing "that bit" as the obvious truth of the matter.

noisebeam

I believe that private drives (home, business: strip mall, gas station, etc.) are not considered intersections. Add to this a number of mid block collisions are due to crossing where there is no intersection and also include wrong way cyclists.

For example in 2005 Mesa, AZ the data on the surface would indicate 56% intersection related and 44% mid-block collisions.

Now take that 44% mid-block collision and break them down by not counting collisions where the cyclist was crossing the street mid-block (12.3%) and not counting collisions at private drives (25%), then of the total mid block collisions where the cyclist was not crossing the street and the cyclist was not crossing a private drive, then there are remaining 6.5% (1.4% wrong way) mid-block collisions and 81% private drive or intersection related.

Al

The Human Car

Al, thanks for the Mesa bike crash analysis link very interesting (and very different then here.)

Now part of my argument is there is a vast difference between crashes and crashes that cause a fatality. While I do not want to end up in a hospital, it would be preferable to death. To demonstrate how fatality data does NOT follow crash data look at the age of those most represented in crashes (10-15) and those in fatalities (45-54.) No one has studied just the fatality data.

What Mesa reports as mid-block/intersection should be the same thing as what FARS reports, the ratio is different because we are talking about a subset of all crashes.

Thanks to what you provided I would speculate the main cause of cyclists deaths is these two items:
Across Roadway (J-biking?)
Sidewalk - Private Drive - Against Traffic

Both of these should be classified as mid-block crashes but a factual answer to what are the most fatal crash types is still unanswered.