Originally Posted by jon c.

I don't think there are a large percentage of motorists who are that ignorant.

Originally Posted by FBinNY

I won't argue the percentage, but it's certainly a sizeable one for a very simple reasons. First, assumed converse is a very common error. Second, here it's also a convenient assumption because it reinforces what they already want to believe. Logic doesn't matter, people tend to selectively use whatever conveniently reinforces what they already (or prefer to) believe.

So, for those drivers who already get along with cyclists, it's no harm, no foul, but to those who are the likely problems, it "supports" their assumptions.

Originally Posted by FBinNY

There's a very common logic fallacy sometimes called an assumed converse.

So, if people regularly see signage indicating that bikes are legal [here], it's too easy to jump to the conclusion that no sign means no bikes.

This is an extremely old concept in thinking and logic and a reason that the framers felt the need to add the 9th amendment "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people", to the constitution.

It's also why we see phrases like "including....., but not limited to" in contracts.

Originally Posted by jon c.

I don't think there are a large percentage of motorists who are that ignorant.

Originally Posted by JoeyBike

Depends on where you live.

What is the literacy rate in New Orleans?
Megan Holt doubts many people are surprised to learn that New Orleans' adult literacy rate is lower than the national average—the New Orleans Community Data Center estimates the city has a 26 percent low-literacy rate among 18- to 64-year olds, compared to 23 percent nationally. Google Search

Some locations are dumber than others.

Originally Posted by livedarklions

I understand that this fallacy exists, but is there any evidence that it affects significant numbers of people's understandings of the significance of sharrows? I ride in some places where they are common, and I've never seen any evidence of this belief by drivers or riders regarding the notion that other roads were somehow closed to bicycles/

Originally Posted by FBinNY

I'm surprised by the question, so let's turn it around for a moment. Is there any evidence that drivers know what sharrows mean? Even as a cyclist who's been active for 50+ years, very involved in advocacy for decades before I stopped, and should be tuned in, even I'm not sure what they mean. Yes, it's about shared road use, but do they mean a specific lane, or part of the road? Are we to ONLY ride in the marked area? What about in advance of a left? How do they change shared road use? Are they placed on roads deemed preferred for cyclists? Or, are they placed on roads with history of problems?

The fact is that, an all these years, as the markings proliferated, I've NEVER (not once) seen any effort by the various jurisdictions to explain the markings to the public. I guess we're supposed to be psychic.

Back to your question, no I don't know of any studies or evidence, except for the mentioned wife who didn't know, does she count?. So, in lieu of direct evidence let's simply connect the dots and extrapolate. We know about confirmation bias, and I assume you understand assumed converse, so let's overlay that with an estimate of the percentage of drivers who still believe that bikes don't belong on the road, or at least wish that that were true, and drive accordingly, and draw conclusions.

As I said in my post, I doubt that this is an issue with drivers who are generally bike friendly, and won't change their thinking. OTOH - it "confirms" the beliefs of bike unfriendly drivers who will assumed that sharrowed roads are the exception where bikes are allowed, otherwise why would we need them.

BTW- Over in The UK they just completed a study of driver road sign knowledge, and found that a staggering percentage of drivers didn't know what most graphic signs meant, including critical ones like "do not enter".

Originally Posted by livedarklions

.....I can see arguing they're largely ineffective because too vague, but you guys are the ones claiming actual bad effects (rather specific ones), so I think that requires some burden of proof beyond "connect the dots and extrapolate". .....

Originally Posted by FBinNY

How do they change shared road use? Are they placed on roads deemed preferred for cyclists? Or, are they placed on roads with history of problems?

Originally Posted by FBinNY

I'm surprised by the question, so let's turn it around for a moment. Is there any evidence that drivers know what sharrows mean? Even as a cyclist who's been active for 50+ years, very involved in advocacy for decades before I stopped, and should be tuned in, even I'm not sure what they mean. Yes, it's about shared road use, but do they mean a specific lane, or part of the road? Are we to ONLY ride in the marked area? What about in advance of a left? How do they change shared road use? Are they placed on roads deemed preferred for cyclists? Or, are they placed on roads with history of problems?

Originally Posted by jon c.

...and sharrows are by far the cheapest option.

Originally Posted by FBinNY

… Wouldn't it be more sensible to ask those who like them to show they make sense, and the benefits exceed potential drawbacks?

Originally Posted by jon c.

I'm not certain why they're placed where they are. In the city they seem to be placed to remove riders from the door zone or on streets where they want traffic to move slowly (around the university).

Originally Posted by FBinNY

I'm not invested enough either way to bother debating, but like how you cleverly turn logic on it's head here. You start by acknowledging possible ineffectiveness, but then flip the burden of proof onto those who don't like them. Wouldn't it be more sensible to ask those who like them to show they make sense, and the benefits exceed potential drawbacks?

Maybe the FDA could adopt this logic and say all drugs are OK, until/unless they're proven dangerous or ineffective. Let's not debate this, it's purely rhetorical.

Originally Posted by livedarklions

Don't accuse me of bad logic, then tell me not to answer. "They do no good" and "they do harm" are very different claims requiring different burdens of proof.
.....

Originally Posted by mr_bill

So, still riding to and from BIDMC, already 1/3 way through treatment, though the BU Bridge is getting steeper with each passing week.

I come here to praise The Minuteman Bikeway, Alewife Linear Park, Somerville Community Path, and the Dr. Paul Dudley White Bikepath, plus the various simple changes made to streets that make connecting these possible for me.

Thank you Arlington, Cambridge, Somerville, Boston, and Brookline.


The Minuteman Bikeway is where the journey starts, and I'm thrilled that a worker in a cherry picker recently fixed the RRFB (Rectangular Rapid Flashing Beacons) at the Mill Street crossing, though honestly most drivers still are oblivious:


I'm travelling mid-day, so I miss the sometimes chaos at this too small two stage bike queue box, but even with my lost marbles, I manage this block fine:


The new-ish signal at Lake helps a lot. I just wait, wait, and wait for the bike green, bobble head making sure all cross traffic has actually the ____ stopped, and then happily continue onward:


Now onto the beginning of Alewife Linear Park, this cantilever over Yates Pond is such a huge improvement over the "take the lane" (and it still is a sucky road surface) back in the day. One note, it's amazing how often drivers will preemptively stop for me. They see me from a long way back and just usually yield, even without the beg button, at least during off peak hours:


Heading around Russel Field. P.S. Love that they removed the stop signs at the Harvey Street dead end:


The crossing at Cameron Ave, the boundary between Cambridge and Somerville, and the boundary between Alewife Linear Park and Somerville Community Path:


And now, this surprised me. I expected to walk through Davis. But mid-day, with the on-street dining reducing this to a single lane, the drivers are calmed. It's so bad here it's really really good:


And ironically, once I turn off Holland onto Grove it gets hard with absolute nuts often racing to the stop sign, but it's a short street:


To be continued....

-mr. bill

Originally Posted by mr_bill

So, I've been remiss on posting the rest of my journey.

Continued:

Amazing how often Blue Bikes docks are either filled or empty. Here at Cedar St. very empty:


However, that first block of Cedar St. was way uncomfortable, so after this ride I switched to Hancock to Spencer, even though that was a standing start climb up Cedar. Lesson learned:


When you can't road, the sanctuary of even plastic bollards is HUGE. Greatly reduced the need for constant "situational awareness" (which was my Achilles Heel):


The last leg of deep end was the one block of Mossland to Somerville Ave. In this case, I'm being shepherded by a street cleaner:


Oxford Street, "sharrows on steroids" and this segment downhill. Total sanctuary:


After a one block jog on Kirkland Street, the cut through in Harvard Square made this trek possible. One block of two-way Quincy Street was easy enough, then the two-way bike lane on One-way Quincy was wonderful:


Although it ran into the always red bike signal to continue on Quincy. Part of me cursed how they couldn't time this better. BUT, once green, no motor traffic behind me at all. Wonderful:


Leading to an easy crossing of Harvard St:


And an easy crossing of one way Mass Ave:


...continued...

-mr. bill

Originally Posted by mr_bill

And then the wonderful Bow and DeWolfe St to get to Paul D. White Bike Path (John Weeks Bridge ahead):






Now, I wish I could say I can't believe how bad the Paul D. White Bike Path is on the Cambridge Side, but I've been watching this slowly die for years. I am eternally grateful that they didn't fix it now. But note the brand new surface to the left. Grrr:



In the rest of the enlightened world a bike lane over a bridge is not put on the crush side of a barrier, but still, this makes it easy to cross the BU Bridge. However, the BU Bridge got steeper and steeper during my radiation therapy:


Didn't love this crossing, though I did ride it to BIDMC but walked it coming home:



...continued...

-mr. bill

Originally Posted by mr_bill

On the other side of Com Ave entering Brookline, and their amazing sequence of one way general traffic but two way bike traffic at Essex and Ivy:




Carlton crossing Beacon:




Which turns into Colchester then Chapel (Longwood stop on the left):


Crossing Longwood stop on foot:



...continued...

-mr. bill

Originally Posted by mr_bill

Through the park and about to enter Boston:


The Short Street Steps:


Crossing Riverway:


Thankfully Winsor School was quiet while I salmoned Short Street:


The very nice alley at Winsor School:


The longest wait ever to cross Brookline:


Finally on the BIDMC campus:


Walking to parking:



-mr. bill

Originally Posted by FBinNY

As I said, I'm not invested either way. I originally posted about assumed converse in response to Daihard's reference to his wife.

So, sorry, I simply won't get drawn into an argument about this.

That said, on this issue and many others, I'm more interested in encouraging people to broaden their outlook and think for themselves, and possibly introducing new or different ways of looking at things.

I mentioned confirmation bias earlier, and it's real and has infected just about everything, not only here, but throughout the political spectrum.

So, I feel a need to sometimes play devil's advocate, and combat some of the preaching to the choir here on BF. After all, this is a forum, not a church.

Originally Posted by mr_bill

Specifically on the sharrows:

I frequently rode on Oxford street before the sharrows, and continue to ride on it after the sharrows. They've made no difference in MY behavior (I always took the lane there), but I immediately noticed far more people on bikes riding in the center of the lane. They've also quieted the "drivers of motor vehicles" too. Another huge help later was another traffic control device, the speed limit was reduced to 25 mph. And there are speed tables at many intersections.

The sharrows through Harvard Square have made a HUGE difference in the behavior of "drivers of motor vehicles." (This is MA HOLE ground zero.)

The sharrows in Brookline are good, but fading. Biggest help is the one ways keep "drivers of motor vehicles" from cutting through, while the contra-bike lanes permit a passage for people on bikes. The sharrows seem to complement the contra-bike lanes.

Finally, some of the first studies on sharrows took place on Mass Ave in Cambridge. Professor Peter Furth of Northeastern invented the "sharrows on steroids."

-mr. bill

Originally Posted by JoeyBike

Breaking in my new (4-days old) Surly Lowside in my urban landscape (NOLA) i came across this sharrow indicating that bikes should take the lane. Never seen any exactly like this before. Royal Street just East of the French Quarter.

Enjoy

Originally Posted by mr_bill

Finally, some of the first studies on sharrows took place on Mass Ave in Cambridge. Professor Peter Furth of Northeastern invented the "sharrows on steroids."