Advocacy & Safety - Proper lane positioning

Lane positioning often comes up in this forum. Often in regard to how much lane you should take/or not take to be given the most room by motorists.

According to the report/research mentioned below 3-4ft from the curb is the sweet spot. At least in Florida. Worth a read.

Florida DOT released this report in Sept.
"Operational and Safety Impacts of Restriping Inside Lanes
of Urban Multilane Curbed Roadways to 11 Feet or Less to
Create Wider Outside Curb Lanes for Bicyclist"

"5.1.3 Relationship between Motor Vehicles Lateral Clearance and Bike Position from
Curb
The relationship between a motor vehicle’s distance from other motor vehicles and the lateral
positioning of bicyclists from the curb is depicted in Figure 6. Intuitively, one would expect that
the closer you ride to the curb, the more lateral separation you have. On the contrary, the results
presented in Table 4 and Figure 6 show that riding closer to the curb results in a smaller
separation. Field observations revealed that when bicyclists ride closer to the curb, some motor
vehicles, especially compact cars attempt to fit in the lane without laterally shifting to the
adjacent lane, hence causing lesser distance. On the other hand, the results show that riding too
far from the curb also results in a shorter distance. It seems that there is a spot between 3 and 4 ft
from the curb that results in the greatest lateral separation between motor vehicles and bicyclists.
It should be noted however, that higher standard deviations were observed. This was mainly
caused by the fact that some drivers choose to stay within the outside through lane while others
laterally shift to the inside lane"
http://www.dot.state.fl.us/research-center/Completed_Proj/Summary_RD/FDOT_BDK82%20977-01_rpt.pdf

3-4ft from the curb is the sweet spot.

Tried that this AM. Got buzzed by 4 vehicles so I moved to the center of the lane.
No more buzz........

"Motorists provided 0.5 ft additional lateral separation to female bicyclists and 0.35 ft additional separation to casually dressed compared to athletically dressed cyclists."

That's it ... I'm finally gonna come out of my wife's closet!

the study was very particular about which roads they found that sweet spot positioning on.

best passing clearance in wide outside lane on multiple lane roads, without on street parking, isn't it? further left got closer passing, and passing distances went down as congestion went up.

at some point when the road and the lane becomes wide enough, 10 wheels technique isn't necessary, or even legal.

The fact passing clearance went down as traffic congestion went up is what is significant out of this study to me.

3-4 feet for best passing clearance, the supposed 'sweet spot'? Far from a blanket rule, but a nice baseline perhaps.

According to the report/research mentioned below 3-4ft from the curb is the sweet spot. Which means that if they paint a average 3 foot bike lane from the curb in a mandatory use states, it becomes impossible to legally ride the 'sweet spot'. And gets cyclist even closer passing than no line.

"Motorists provided 0.5 ft additional lateral separation to female bicyclists and 0.35 ft additional separation to casually dressed compared to athletically dressed cyclists."

That's it ... I'm finally gonna come out of my wife's closet!

:roflmao2::lol::D:roflmao::thumb:

So we are supposed to gauge how close someone is going to pass us, according to that report? Ultimately putting our own lives' at risk.....I think not. I am going to stick to 'taking the lane'.

Which means that if they paint a average 3 foot bike lane from the curb in a mandatory use states, it becomes impossible to legally ride the 'sweet spot'. And gets cyclist even closer passing than no line.

I didn't read the whole thing yet. But I don't believe that the study was on lanes with bike lanes. So you'd have to do another study on passing offend bike lanes. As Bekologist said. It was only particular lanes where this sweet spot was.

So we are supposed to gauge how close someone is going to pass us, according to that report? Ultimately putting our own lives' at risk.....I think not. I am going to stick to 'taking the lane'.

I don't think this is what it's saying. Just that they found that people gave the most room to riders that are about 3-4ft into the lane. Depending on the lane size that could be taking the lane.

bikelanes have been proven to smooth out passing behaviors and overall traffic flow. this study was not about the effect of bikelanes on passing behavior.

it found, in some cases like amply wide outside lanes on multiple lane roadways, that rider positioning 3-4 feet out in a shareable lane provided the maximum passing clearance, generally speaking.

However, and what i truly found interesting in the study, passing clearance went down as traffic congestion increased.

bikelanes have been proven to smooth out passing behaviors and overall traffic flow.

"Smooth out"?


However, and what i truly found interesting in the study, passing clearance went down as traffic congestion increased.

"Interesting", in which way?

that's what the studies indicate. smoother passing, less abrupt traffic maneuvers to get around bike traffic, less disruption in overall traffic flow, 'smoother'.

and the florida study mentions the decrease in passing clearance as traffic congestion increased. I didn't fully dissect the paper, its cuite involved, however.

the study synopsis was that sweet clearance isn't so sweet if the traffic is congested, that passing clearances decreased as volume increased.

I find this damning against wide outside lanes as the end-all be all for bike traffic. which, of course, they aren't.

Lane positioning often comes up in this forum. Often in regard to how much lane you should take/or not take to be given the most room by motorists.

According to the report/research mentioned below 3-4ft from the curb is the sweet spot. At least in Florida. Worth a read.

Florida DOT released this report in Sept.
"Operational and Safety Impacts of Restriping Inside Lanes
of Urban Multilane Curbed Roadways to 11 Feet or Less to
Create Wider Outside Curb Lanes for Bicyclist"

"5.1.3 Relationship between Motor Vehicles Lateral Clearance and Bike Position from
Curb
The relationship between a motor vehicle’s distance from other motor vehicles and the lateral
positioning of bicyclists from the curb is depicted in Figure 6. Intuitively, one would expect that
the closer you ride to the curb, the more lateral separation you have. On the contrary, the results
presented in Table 4 and Figure 6 show that riding closer to the curb results in a smaller
separation. Field observations revealed that when bicyclists ride closer to the curb, some motor
vehicles, especially compact cars attempt to fit in the lane without laterally shifting to the
adjacent lane, hence causing lesser distance. On the other hand, the results show that riding too
far from the curb also results in a shorter distance. It seems that there is a spot between 3 and 4 ft
from the curb that results in the greatest lateral separation between motor vehicles and bicyclists.
It should be noted however, that higher standard deviations were observed. This was mainly
caused by the fact that some drivers choose to stay within the outside through lane while others
laterally shift to the inside lane"
http://www.dot.state.fl.us/research-center/Completed_Proj/Summary_RD/FDOT_BDK82%20977-01_rpt.pdf

My riding experience bears this out. When I ride a foot or so from the curb I get more close passes, but when I ride 3 or 4 feet from the curb I get more clearance with vehicles passing my left side. Or as other's here have said, the more room that we leave to our right the more room motorists give us on our left when they pass us.

Of course it does come with diminishing returns, i.e. the further to the left one rides when not totally needed the more harassment one starts to receive again.

The irony is that on some roads that riding 3 - 4 feet out from the curb/shoulder will place the cyclist further to the left in the lane then on other roads. One of the roads that I ride as I've said in another thread has a VERY wide outside lane. Wide enough that two average sized cars can drive side-by-side without a problem and it has a bike lane.

If the bike lane had been left as a shoulder cyclist's would have been safer as it would have given cyclists enough space to their right to avoid most obstacles, AS WELL as providing the cyclist with clear road to ride in.

So yes, I agree that 3 - 4 feet is the "sweet spot" on the road. Also as I've said before there should be some sort of middle ground between the VCers and the bicycle specific infrastructure crowd.

Which means that if they paint a average 3 foot bike lane from the curb in a mandatory use states, it becomes impossible to legally ride the 'sweet spot'. And gets cyclist even closer passing than no line.

Which is why as I've said before what should be done is to measure 3 - 4 feet from the right side of the road then stripe a bike lane. If there is either on street parking or there is already a shoulder on the road then measure 3 - 4 feet from either the on street parking or the shoulder and then add a bike lane.

And for states like Florida with a mandatory bike lane use law measure 3' from the left most edge of the bike lane and stripe a "no mans" zone to force motorists to give cyclists 3' when passing.

Of course, I know that that will never happen. But in my opinion that is how it should be done, IF we're to have bicycle infrastructure forced on us.

Lane positioning often comes up in this forum. Often in regard to how much lane you should take/or not take to be given the most room by motorists.

According to the report/research mentioned below 3-4ft from the curb is the sweet spot. At least in Florida. Worth a read.

Florida DOT released this report in Sept.
"Operational and Safety Impacts of Restriping Inside Lanes
of Urban Multilane Curbed Roadways to 11 Feet or Less to
Create Wider Outside Curb Lanes for Bicyclist"

"5.1.3 Relationship between Motor Vehicles Lateral Clearance and Bike Position from
Curb
The relationship between a motor vehicle’s distance from other motor vehicles and the lateral
positioning of bicyclists from the curb is depicted in Figure 6. Intuitively, one would expect that
the closer you ride to the curb, the more lateral separation you have. On the contrary, the results
presented in Table 4 and Figure 6 show that riding closer to the curb results in a smaller
separation. Field observations revealed that when bicyclists ride closer to the curb, some motor
vehicles, especially compact cars attempt to fit in the lane without laterally shifting to the
adjacent lane, hence causing lesser distance. On the other hand, the results show that riding too
far from the curb also results in a shorter distance. It seems that there is a spot between 3 and 4 ft
from the curb that results in the greatest lateral separation between motor vehicles and bicyclists.
It should be noted however, that higher standard deviations were observed. This was mainly
caused by the fact that some drivers choose to stay within the outside through lane while others
laterally shift to the inside lane"
http://www.dot.state.fl.us/research-center/Completed_Proj/Summary_RD/FDOT_BDK82%20977-01_rpt.pdf

I have posted my review of the March 2011 Florida DoT study of the traffic effect of wide outside lanes. The URL of my review is:
http://johnforester.com/Articles/Facilities/Florida%20Wide%20Outside%20Lanes.pdf

As I see it, the investigators went to a great deal of trouble to make a study without understanding what its real point should have been. The purpose of wide outside lanes is to allow safe overtaking within the lane instead of either unsafe squeezing by or using the adjacent lane. The investigators measured clearance distances between cyclists and motorists for a variety of outside lane widths, with distances of cyclists from curbs. But they failed to work out how wide a lane had to be to produce safe overtaking behavior, and how close to the lane line on his left the cyclist had to ride to strongly persuade motorists to change lanes to overtake. All that work, for almost nothing.

WHY on earth would a rider in a wide outside lane require motorists to 'change lanes to overtake'?


how close to the lane line on his left the cyclist had to ride to strongly persuade motorists to change lanes to overtake

Thats' NOT recommended riding technique for wide outside lanes there john. back to remedial bike learnin' for yas!

Strongly persuade motorists to change lanes? what bluffery and a bassoon.

Which means that if they paint a average 3 foot bike lane from the curb in a mandatory use states, it becomes impossible to legally ride the 'sweet spot'. And gets cyclist even closer passing than no line.

Gotta agree... so the solution is to get 5 foot+ bike lanes as "the standard."

I have posted my review of the March 2011 Florida DoT study of the traffic effect of wide outside lanes. The URL of my review is:
http://johnforester.com/Articles/Facilities/Florida%20Wide%20Outside%20Lanes.pdf

As I see it, the investigators went to a great deal of trouble to make a study without understanding what its real point should have been. The purpose of wide outside lanes is to allow safe overtaking within the lane instead of either unsafe squeezing by or using the adjacent lane. The investigators measured clearance distances between cyclists and motorists for a variety of outside lane widths, with distances of cyclists from curbs. But they failed to work out how wide a lane had to be to produce safe overtaking behavior, and how close to the lane line on his left the cyclist had to ride to strongly persuade motorists to change lanes to overtake. All that work, for almost nothing.

The problem is when you make a lane wide enough to produce "safe overtaking behavior," you also tend to encourage motorists to speed. This is why road diets focus on making the lanes or even the whole road appear narrower... which is also what bike lanes can do.

The problem is when you make a lane wide enough to produce "safe overtaking behavior," you also tend to encourage motorists to speed. This is why road diets focus on making the lanes or even the whole road appear narrower... which is also what bike lanes can do.

So you say. I understand that the effect is small. Since you say otherwise, please provide a reasonable study demonstrating your claim.

the sophistry of a reasonable red herring doesn't mean much in a discussion of riding the sweet spot in uncongested, wide outside lanes 3-4 feet from the edge and not having to 'strongly persuade motorists to change lanes.'

Time for some Bike 1-2-3 for some of us, apparently.

It should be noted however, that higher standard deviations were observed.

This part concerns me. I'm far more interested in variance (i.e., uncertainty, aka risk) than I am with mean distances between cyclists and passing motorists. It isn't average or the typical drivers that pose the greatest danger to cyclists, but rather (half of) the drivers who are the outliers.

On streets where I typically ride, which tend to have lanes less than fourteen feet wide, I personally tend to ride somewhere between the center of the lane and the left tire track. My own experience is that when I ride there, motorists will predictably completely exit my lane to pass. If I ride right, some motorists inevitably try to share the lane with me. If I ride in the right tire track, some motorists will not completely leave the lane to pass, leaving less than three feet of clearance. On average, I get receive less room from passing vehicles than if I rode right. However, by riding where I do, I seem to receive more room from the motorists who pass the closest compared to those who pass the closest when I ride right or in the right tire track.

For me, it's pretty simple; right tire track in the right lane, right tire track of the left lane when I'm turning left. So far, following this formula, I have been buzzed 1x. In 2011. (Car-free, btw....)

the number of wide outside lanes around here is so small to make it almost pointless to consider that case. The one road with wide outside lanes around here has a bike path (wide sidewalk) next to it, but I don't ride on that because there really is no point and there are 5 stop signs vs. none on the road. Even with the bike path, I don't see any problems with motorists on that road. Where I do see problems is the 55mph road that goes by my house. It would have wide outside lanes, but they painted shoulders. There are some idiots that think that just because they aren't over the white line, that's enough passing distance. I have no way of proving this, but I feel like the white line promotes close passing. I'm also willing to consider the notion that these people are just clueless jerks.

As far as bike lanes and road diets, I really don't see it. Fraternity row here in town has bike lanes, and they have also had to put in speed bumps and people still speed down the road. Maybe if they put in trees in between the sidewalk and the road they would have better speed limit compliance, but the bike lanes aren't working. I don't go down that road anymore, there is a parallel route that avoids a couple of stop signs, and I'm not a big fan of speed bumps.

This part concerns me. I'm far more interested in variance (i.e., uncertainty, aka risk) than I am with mean distances between cyclists and passing motorists. It isn't average or the typical drivers that pose the greatest danger to cyclists, but rather (half of) the drivers who are the outliers.

On streets where I typically ride, which tend to have lanes less than fourteen feet wide, I personally tend to ride somewhere between the center of the lane and the left tire track. My own experience is that when I ride there, motorists will predictably completely exit my lane to pass. If I ride right, some motorists inevitably try to share the lane with me. If I ride in the right tire track, some motorists will not completely leave the lane to pass, leaving less than three feet of clearance. On average, I get receive less room from passing vehicles than if I rode right. However, by riding where I do, I seem to receive more room from the motorists who pass the closest compared to those who pass the closest when I ride right or in the right tire track.

Don't forget that there is a member here (he's posted in this thread) who thinks that riding like that is "rude" to motorists and that we should allow for same lane/partial lane passing. He also thinks (despite the number of states not only submitting bills but passing laws requiring at least 3' passing buffers) that more states are passing laws to allow partial lane changes to pass a cyclist.

For me, it's pretty simple; right tire track in the right lane, right tire track of the left lane when I'm turning left. So far, following this formula, I have been buzzed 1x. In 2011. (Car-free, btw....)

Agreed, and I have to laugh at those members here who think that riding that way is rude or inconsiderate, or not needed. I have to wonder if they actually live and ride in the "real world" or if they live and ride in some sort of fantasy world where cyclists are never harassed and they have well maintained bicycle infrastructure.

I don't think this is what it's saying. Just that they found that people gave the most room to riders that are about 3-4ft into the lane. Depending on the lane size that could be taking the lane.

I know that is not what the report is saying. All these 'feel good' reports saying if a cyclist does this or that, things between cyclists' and motorists' will be okey dokey. When are government agencies going to put out a report directed at motorists as to their respecting cyclists on the road without having someone tell them how to do it?:notamused:

Agreed, and I have to laugh at those members here who think that riding that way is rude or inconsiderate, or not needed. I have to wonder if they actually live and ride in the "real world" or if they live and ride in some sort of fantasy world where cyclists are never harassed and they have well maintained bicycle infrastructure.

DC, if they think I'm rude for doing THAT, wait til they MEET me! (LOL)

I think I jinxed myself, though -- got buzzed 3x TODAY! Oh, sailors would have blushed to hear me.......

DC, if they think I'm rude for doing THAT, wait til they MEET me! (LOL)

I think I jinxed myself, though -- got buzzed 3x TODAY! Oh, sailors would have blushed to hear me.......

DM,

If ya can make a "Jarhead" blush then I'd be impressed. ;)

ride only as far right as is safe.

in shareable lanes, that is not forcing lane changes to overtake. this 3-4 feet 'sweet spot' ISN'T "the left tire track". :roflmao: the study doesn't support a far left of the lane anyway. The study distinctly mentioned how the passing became closer and more likely to be abrupt or hazardous in some manner.

Some of you seem to be purporting you are unable to handle -are unwilling to accept - legal, partial lane changes to pass. Even when safely positioned in the, say, right tire track of a road to share the road? Passing movements occur regularly on every ride on even a moderate traffic road and likely hundreds of times of times a week for the average rider, if not thousands a week for us busy urban riders...


Claims of riding to prevent partial lane changes to pass in all road conditions less than 14 feet wide is where the rhetoric starts to ring hollow. It just doesn't stand up to reality, much less the metric of reasonable, safe road use by a bicyclist.

Personally,I'm quite assertive in my road position, but my road use is much more moderate -it could even be characterized as "reasonable" - than these claims of unsharing lane use.

Where do some of you guys ride, anyway? It sounds like fantasy baseball camp or something.

Reading the 'share the lane' references(positive or negative) in some of the posts, got me to wondering why does society at large(and some cyclists), expect a cyclist to 'share the lane', instead of passing like passing another 'motorized' vehicle. Not as in, one vehicle in front of another. But as in, the motorist being evenly positioned with the cyclist at the same physical point. This just leads to the excuse by motorists of, 'I never saw her/him', when they pass to close and/or, have drifted towards the curb, injuring/killing the cyclist.

Reading the 'share the lane' references(positive or negative) in some of the posts, got me to wondering why does society at large, expect a cyclist to 'share the lane', instead of passing like passing another 'motorized' vehicle. It just astounds me, that the driving public at large(and some cyclists) expects the lane to be 'shared'. Not as in, one vehicle in front of another. But as in, the motorist being evenly positioned with the cyclist at the same physical point. This just leads to the excuse by motorists of, 'I never saw her/him', when they have drifted towards the curb, and injuring/killing the cyclist.

Society at large actually expects cyclists to just get out of the way. Share the road or share the lane is just a feeble slogan to try to convince cyclists that society at large actually cares about cyclists.

If society at large actually supported cycling by the general public, this message would be conveyed to all motorists for all situations involving cyclists:

http://photos1.meetupstatic.com/photos/event/a/e/d/f/event_13724767.jpeg

Society at large actually expects cyclists to just get out of the way. Share the road or share the lane is just a feeble slogan to try to convince cyclists that society at large actually cares about cyclists.

If society at large actually supported cycling by the general public, this message would be conveyed to all motorists for all situations involving cyclists:

http://photos1.meetupstatic.com/photos/event/a/e/d/f/event_13724767.jpeg

Very true!:thumb:

Great addendum!:thumb:

Claims of riding to prevent partial lane changes to pass in all road conditions less than 14 feet wide is where the rhetoric starts to ring hollow. It just doesn't stand up to reality, much less the metric of reasonable, safe road use by a bicyclist.

There is nothing wrong with positioning oneself in the lane in a manner that minimizes risk while being passed. Risk is quantified with variance. To minimize risk, one must minimize variance (i.e., standard deviation of passing clearance must be minimized). To put it another way, there is nothing wrong with positioning oneself in the lane so that the behavior of passing motorists is most predictable. Partial lane changes to pass are not, in and of themselves, anything to worry about (although they are virtually never necessary). When make only a partial lane change and fail to leave safe clearance between their vehicle and the cyclist they're passing, it becomes a problem, one that is not uncommon. (I see it a few times per week when I ride in the right tire track.)

If the lane is sufficiently wide, i.e., more than 14 feet from the painted line to the nearer of the curb or the door zone, I'll ride right. Otherwise, I'm taking the lane. If I'm taking the lane, I make it clear to motorists that I'm taking the whole lane. There is nothing unreasonable about that. If it's safe for them to make a partial lane change and pass, it is nearly always safe for them to make a full lane change to pass.

There is a reason I use 14 feet as the critical width to decide whether or not to ride right, and it is most certainly reality based.


Since the minimum clearance for passing a bicyclist is 3 feet … and the total width of larger motor vehicles (with extending mirrors) is commonly 8 feet or more, an outside traffic lane with less than 14 feet of width for travel is commonly not wide enough to accommodate passing motor traffic within the lane. Where restricted conditions prevent inclusion of bicycle lanes or paved shoulders on urban roadways, Florida Department of Transportation engineering guidance recommends an outside lane width of 14 feet to “allow passenger cars to safely pass bicyclists within a single lane,” i.e., without the need for passing motor vehicles to change lanes …. Source (http://floridabicycle.org/rules/bikelaw.html)

riding 10 feet from the curb in a 12 foot lane to force cars to fully change lanes to pass would be considered unreasonable by most people, bicyclists included, and hardly necessary to "maximize predictability of motorists" forcing them to fully change lanes to pass.

The study (in Florida, nonetheless) found riding too far to the left increased the unpredictability of motorists.

riding 10 feet from the curb in a 12 foot lane to force cars to fully change lanes to pass would be considered unreasonable by most people, bicyclists included, and hardly necessary to "maximize predictability of motorists" forcing them to fully change lanes to pass.

The study (in Florida, nonetheless) found riding too far to the left increased the unpredictability of motorists.

Because the general expectation is the a cyclist should not only ride in the gutter, they should stay in the gutter.

There is nothing wrong with positioning oneself in the lane in a manner that minimizes risk while being passed. Risk is quantified with variance. To minimize risk, one must minimize variance (i.e., standard deviation of passing clearance must be minimized). To put it another way, there is nothing wrong with positioning oneself in the lane so that the behavior of passing motorists is most predictable. Partial lane changes to pass are not, in and of themselves, anything to worry about (although they are virtually never necessary). When make only a partial lane change and fail to leave safe clearance between their vehicle and the cyclist they're passing, it becomes a problem, one that is not uncommon. (I see it a few times per week when I ride in the right tire track.)

If the lane is sufficiently wide, i.e., more than 14 feet from the painted line to the nearer of the curb or the door zone, I'll ride right. Otherwise, I'm taking the lane. If I'm taking the lane, I make it clear to motorists that I'm taking the whole lane. There is nothing unreasonable about that. If it's safe for them to make a partial lane change and pass, it is nearly always safe for them to make a full lane change to pass.

There is a reason I use 14 feet as the critical width to decide whether or not to ride right, and it is most certainly reality based.


Since the minimum clearance for passing a bicyclist is 3 feet … and the total width of larger motor vehicles (with extending mirrors) is commonly 8 feet or more, an outside traffic lane with less than 14 feet of width for travel is commonly not wide enough to accommodate passing motor traffic within the lane. Where restricted conditions prevent inclusion of bicycle lanes or paved shoulders on urban roadways, Florida Department of Transportation engineering guidance recommends an outside lane width of 14 feet to “allow passenger cars to safely pass bicyclists within a single lane,” i.e., without the need for passing motor vehicles to change lanes …. Source (http://floridabicycle.org/rules/bikelaw.html)

+1

Which is why as I've said before what should be done is to measure 3 - 4 feet from the right side of the road then stripe a bike lane. If there is either on street parking or there is already a shoulder on the road then measure 3 - 4 feet from either the on street parking or the shoulder and then add a bike lane.

And for states like Florida with a mandatory bike lane use law measure 3' from the left most edge of the bike lane and stripe a "no mans" zone to force motorists to give cyclists 3' when passing.

Of course, I know that that will never happen. But in my opinion that is how it should be done, IF we're to have bicycle infrastructure forced on us.

Really? You actually believe that?

riding 10 feet from the curb in a 12 foot lane to force cars to fully change lanes to pass would be considered unreasonable by most people, bicyclists included, and hardly necessary to "maximize predictability of motorists" forcing them to fully change lanes to pass.

Indeed. Of course no one has mentioned riding two feet from the centerline. Riding in the center of the lane to the left tire track generally leaves a cyclist significantly more than two feet from the centerline in most every city I've ever lived (except Key West, FL).

When a cyclist's position in the lane encourages motorists to completely exit the lane to pass, that does indeed increase predictability compared to lane positions that allow motorists to share the lane or partially exit the lane when passing.


The study (in Florida, nonetheless) found riding too far to the left increased the unpredictability of motorists.

The study offers very little statistically meaningful information about those who ride more than five feet from the curb. The sample size of that group was only 29, spread over 19 sites.