Daily Commute

The LAB is touting this Texas study as evidence that bike lanes make cyclists safer. I think data from the study shows only that drivers buzzed cyclists more closely on roads with striped lanes than on roads without stiped lanes. The study's authors then declared that it's safer for cars to buzz cyclists more closely than to give cyclists more space. The study's data also showed that on roads with bike lanes, cars were less likely to move to the left to move around cyclists. I'd argue that it's less safe for cyclists when cars refuse to move over and buzz cyclists more closely.

The authors' conclusions were based on the assumption (they even labeled it an "assumption" on page 26) that their paid, specially instructed cyclists rode where they were safest. So, since cars buzzed the paid bike lane cyclists more closely than the paid WOL cyclists, the author's assumed that the paid bike lane cyclists were safer close to traffic. No data supported that assumption.

There was one positive--their paid cyclists rode a little farther from the curb, but there are other ways to achieve that (education, signage). Since they hired the cyclists and gave them instructions, it would have been interesting to see if cyclist behavior changed the same or more if the cyclists were told that they were safer if they did not hug the curb.

Another problem is that the authors instructed their paid cyclists to ride on the right (page 20). This inhibited the free choice of lane position.

What a waste of government money.

Edit: I was hoping to focus on what this study did and did not show, as well as how it could have been done usefully. So let's stick to comments on this study, and not just repeat the standard pro- and anti-bike lane arguments we're all tired of. Some of those arguments are relevant to the study, but please try to link them to the study.

Second edit: With supcom's permission, I've asked a mod to merge this into his original thread on this topic.

Third edit: I deleted or modified posts from my thread now-merged thread that referred to the "other" thread.

R-Wells

I can see how bike lanes are inefficient the way they are being used now.

But I also can see how bike lanes are benefiting cyclists.
The more bike lanes we have the more attention we draw and the more tax money we spend on an alternative mode of transportation.
And the more bike lanes we have the more visable cycling is as a acceptable mode of transportation.

And I don’t really see the study as a total waste of money.
More as the adolescence of bike studies.

Daily Commute

Why is closer passing automatically safer passing? What they really measured was how the bike lane stripe made their hired and specifically instructed cyclists feel. It did not measure actual safety.

N_C

I have some questions about this first of all. The individual or group that conducted this study hired & paid cyclists to ride in the BL with instructions on how to ride, correct? If that is the case then isn't htis study bogus with manipulated results? Shouldn't it have been done with cyclists who did not know they were part of a study or survey & with out insturctions as to where & how to ride?

Daily Commute

The cyclists were given a copy of the Texas bike statutes and told to ride to the right. They were also given instructions so that there weren't two of them in the same spot.

Brian Ratliff

Actually, this is not the instruction they were given. Here is the actual quote from the report:

(emphasis mine.)

"ride to the right" is very different than "ride on the righthand side of the road." And there are no instructions on how far to the right they should ride. Their instructions sound reasonable to me. They actually took pains to avoid this particular issue.

As for the "...they were paid" part: they were paid for their time; perfectly reasonable. In fact, if you don't like this, don't take any meds from the pharmacy. Most or all the participants in medical trials and studies are paid or compensated in some way for their time.

DC, I'd suggest you take an hour or so to thoroughly read the report before dumping on it again. It just makes you look silly. I'd like to hear what you thought of it, but it sounds like you just skimmed it with a closed mind and cherry picked criticisms, which turned out to be utterly wrong anyway. Take your time and read the report with an open mind. Don't reject their data or their conclusions out of hand. Then we can discuss. Report back when you've done this and respond to the report with clear arguments in favor or against their methodology or conclusions. Until then... adios.

Daily Commute

I didn't realize that another thread had been created. Sorry. As I said in that thread, I searched for references to "Texas" before starting this thread (it was a University of Texas study), but no one had used the word "Texas" in the thread, so the search missed it.

The other thread is here. I have no objections if the mods close this thread.

Brian Ratliff

Bump...

For anyone who is interested in actual data and studies, DC started another thread on this study. Here was the previous discussion.

Daily Commute

But bad data are still bad data, and the validity of the study's conclusions depend entirely on the validity of their assumptions, which are not supported by any data. What we are left with is what we already knew--bike lanes make some cyclists feel safer, but claims of actual safety are based on untested assumptions.

Here are my posts from the other thread:

The LAB is touting this Texas study as evidence that bike lanes make cyclists safer. I think data from the study shows only that drivers buzzed cyclists more closely on roads with striped lanes than on roads without stiped lanes. The study's authors then declared that it's safer for cars to buzz cyclists more closely than to give cyclists more space. The study's data also showed that on roads with bike lanes, cars were less likely to move to the left to move around cyclists. I'd argue that it's less safe for cyclists when cars refuse to move over and buzz cyclists more closely.

The authors' conclusions were based on the assumption (they even labeled it an "assumption" on page 26) that their paid, specially instructed cyclists rode where they were safest. So, since cars buzzed the paid bike lane cyclists more closely than the paid WOL cyclists, the author's assumed that the paid bike lane cyclists were safer close to traffic. No data supported that assumption.

There was one positive--their paid cyclists rode a little farther from the curb, but there are other ways to achieve that (education, signage). Since they hired the cyclists and gave them instructions, it would have been interesting to see if cyclist behavior changed the same or more if the cyclists were told that they were safer if they did not hug the curb.

Another problem is that the authors instructed their paid cyclists to ride on the right (page 20). This inhibited the free choice of lane position.

What a waste of government money.

* * *

Why is closer passing automatically safer passing? What they really measured was how the bike lane stripe made their hired and specifically instructed cyclists feel. It did not measure actual safety.* * *

The statutes they were given say to "as near as practicable to the right curb" except in specific situations that don't appear to apply here.

The fact that they used paid cyclists mean that the cyclists were not riding as normal--they knew they were being watched and studied. I did not mean to imply that they paid off the cyclists.

I have read the study. Can you defend its conclusions? Of course, I can understand why you might not want to try to defend such sloppy work.

Brian Ratliff

See the other thread. As a start, please post the Texas bike statute which says "as near as practical..." Note that the "as near as practical..." standard is standard fare in most bike laws and is also very vague.

As for the cyclists knowing they were being watched, its a way of doing it. As long as they did not know what was being studied and what the intent of the study was for the researchers, it is okay. If someone asked to watch you ride your bike down the street, would you change anything about how you ride? It is called a blind study, and it is standard fare amongst scientific studies involving human subjects.

What is your point with all your nitpicks? What effects do you believe "being watched" had on the results? Do you think it made newbies ride further to the right? Do you think it made experienced cyclists ride further to the left?

FWIW, I can defend anything; part of being a good scholar and knowing all sides of an issue. I can defend HH's opinions, yours, anyone's. See the other thread (UT bike lane study) started earlier for my defense of various issues with this particular study. Can't defend nitpicks though, it is up to you to tell me in specific terms how you think your particular nitpick affected the results. It's not good enough to nitpick and then throw everything out. That's called "throwing the baby out with the bathwater." If you think you nit invalidates the results, explain more fully how you think the results are skewed as a result.

Brian Ratliff

The researchers did a good job at explaining their interpretations of the results. Start there. State their interpretation (in good faith; better yet, use a direct quote), then lay out your critique. The report has all you need to structure your specific critique. I don't have time to do your legwork for you. I really am interested in your actual critique though. I have my own opinions about this. But please... you first.

FWIW, there is no way to "measure safety." "Safety" is characterized by the lack of danger. You cannot measure a negative. All you can do is correlate a specific hazard to a level of danger. They also took a stab at this in the literature review.

Brian Ratliff

DC: I did as well. Again, I would like to see specific critiques and how you think, based on their methodology, the issues you raise will affect the results. Otherwise, this is just nitpicking.

DCCommuter

Is the LAB really touting this study? That's pathetic.

Bruce Rosar

LAB gave the report top billing in the 9/25 edition of their newsletter (which apparently was sent out to members who had given their email address to the League).

Bruce Rosar

How about a comment from Bike Lanes and Safety Research in regards to a remarkably similar paper from the '90s?:

Bruce Rosar

IMHO it should have also been done with additional engineering options, including shared lane markings and narrow traffic lanes that weren't segregated.

Daily Commute

Yep, and then our local bike lane advocacy group sent the LAB notice out, stating the conclusions as if that's what the study actually showed, instead of just saying that the conclusions were really just rehashed versions of the assumpsions they started with.

CommuterRun

My own, personal experience shows me that riding to the right of the white line, whether paved shoulder or bike lane, leads to closer and, usually, higher speed passing.

Riding in a centerish lane position, results in being given much more room when being passed at, normally, lower speeds.

The results of this are that riding centerish in a traffic lane is safer than riding to the right of a traffic lane, unless the shoulder is very wide, or it is a very wide lane.

The best bicycling specific facilities would be two narrow vehicle lanes in each direction. Slower vehicles keep to the right lane, faster vehicles may pass, unimpeded by on-coming vehicles, on the left.

I haven't read the LAB study. If it is, in fact, saying that closer passing is safer with the cyclist in a bike lane it's a bunch of hogwash.

I-Like-To-Bike

Don't hold your breath waiting for DC, BR, et al. to report back with anything but the same as always; rants with a bottom line of consistent and persistent bike lane hysteria.

Sidenote: What IS the problem for these anti bike lane fanatics that causes them to snap at the mention of the concept? My guess - The frenzied and over-the-top foaming at the mouth rants are because bike facilities distract attention from the promotion of their pet education schemes. Is ANYONE actually preventing them from bicycling to and fro except in their fevered imagined nightmares?

I-Like-To-Bike

Also bumped from the other thread.

Brian you may be interested in the future comments of DC and comrades on this topic but I'm not. I already know his reponse no matter what is written or not in this or any other study about bike lanes.
Don't hold your breath waiting for DC, BR, et al. to report back with anything but the same as always; rants with a bottom line of consistent and persistent bike lane hysteria.

Sidenote: What IS the problem for these anti bike lane fanatics that causes them to snap at the mention of the concept?

My guess - The frenzied and over-the-top foaming at the mouth rants are because bike facilities distract attention from the promotion of their pet education schemes. Is ANYONE actually preventing them from bicycling to and fro except in their fevered imagined nightmares? .

N_C

It seems this study was done with the intention of producing manipulated results. Why would anyone want to do that? They get a group of cyclists together, give them instructions on how to ride in the BL then study the behavior of the motorists. The cyclists knew they were being studied & had instructions on how to ride. The only thing random is the way the motorists reacted. If this is not manipulating the results I don't what is.

It would have been better if they had not told the cyclists they were being studied & let them ride how they normally would along the roadway to see how they do so & how motorists react. That would have produced real results for study & possible improvements.

I've no problems with doing studies & survey's but it should be done so the results are not manipulated to get the desired result simply because the real results from a non-instructed random study would not be desirable.

Daily Commute

Why is it safer for drivers to buzz by cyclists more closely than to move over? Also, the burden for proving safety (or the lack of danger) is on those who want to radically change how traffic cycling has been done for a century and to corral cyclists into lanes next to (or including) the gutter.

And your point about the study's authors doing an extensive literature review is well taken. There is very little new data in this study--it is mostly a rehash of previous work. Which is part of why the study's date don't prove what it claims to prove. Either you accept the assumptions or you do not. Depending on whether the assumptions are correct, the data show either that bike lanes make cycling more hazardous or less hazardous. But there is no data to support the assumptions, which are questionable.

Also, when it comes to Portland, you say that no one can comment on Portland's bike lanes unless they have ridden the specific lanes at the specific time of day in question. But here, you are willing to back up the study's authors even though you have not ridden the same streets. Doesn't that violate your own rule?

Bekologist

This study showed how bike lane stripes led to more appropriate and safer bicyclist positioning.

Daily Commute

Again, the cyclists were given a manual that said intructed them to stay as far right as practicable (with exceptions that appear not to apply on their test track). They were given no onformation about what that means, and most people misinterpret that as meaning "as far right as possible." The paid cyclists also knew they were being monitored and that they were being paid to follow instructions.

What did it say about appropriate positioning through intersections? Or about whether the cyclists would have picked a better position just be being told, "it's safer at least a few feet from the curb"?

And, of course, even though they were slightly farther from the curb, cars were buzzing them more closely, mitigating or reversing any safety advantage (that's my "assumption," which is back by personal experience and as much data as the author's assumoptions).

Bekologist

being passed safely in a separate lane is hardly misconstrued as 'buzzing'