Advocacy & Safety - Are bike lanes safe or just offer an illusion of safty?

Cyclists Find No Safety in Numbers (http://www.bicycletimesmag.com/content/cyclists-find-no-safety-numbers)

here is the data used in the article:

Pedalcyclists Killed, by Age and Location - State : USA, Year : 2007
Pedalcyclists Killed, by Time of Day and Day of Week - State : USA, Year : 2007
Pedalcyclists Killed in Single Vehicle Crashes, by Vehicle Type and Initial Point of Impact - State : USA, Year : 2007
Pedalcyclists Killed, by Related Factors - State : USA, Year : 2007

http://www-fars.nhtsa.dot.gov/People/PeoplePedalcyclists.aspx

The one thing I like about segregated lanes is that I feel more at ease to go slow. When I'm riding in the midst of traffic, I often feel pressured to keep my speed above 10 miles per hour, which can make steep hills and long distances less enjoyable.

I personally think sharrows are a better option, but if the illusion of safety that lanes provide gets more people riding, perhaps that's a good thing.

It's a good article, worth reading. I think bike lanes increase safety becuae they help keep cars and bike segregated. But, as the article points out, the dangers of intersections still remain. The bike lane is great between intersections, but getting out of the lane and into trafic at the intersection usually is the best strategy.

Bike lanes create a perception (some would say illusion) of safety, because drivers expect cyclists to stay on their side of the white line, and vice versa. Cyclists like the idea, because cars aren't supposed to go there.

The truth is that cars cross the lane at every driveway and intersection. And cyclists need to move to the left edge of the traffic lane at least every now and then because they need to make left turns.

They make traffic situations more complex, by introducing a new. partially segregated stream of traffic, and expecting everyone to blithely share intersections and other crossing areas.

They're useful,and they're a strong encouragement for more folks to ride. Just be careful out there...

Do people really call themselves "Foresterites"? I thought it was a term that other people called them.

It all depends on the details.

Are bike lanes safe or just offer an illusion of safty?

I'm sorry, but I'm not from this country, and I am not familiar with these new term - how you say it, ah - "safty."

-Kurt

I'm sorry, but I'm not from this country, and I am not familiar with these new term - how you say it, ah - "safty."

-Kurt

Go back to Texico, 'ito. :thumb:

Depending on painted lines for an illusion of safety is gonna make you have a bad day sooner or later.

here is the data used in the article:

Pedalcyclists Killed, by Age and Location - State : USA, Year : 2007
Pedalcyclists Killed, by Time of Day and Day of Week - State : USA, Year : 2007
Pedalcyclists Killed in Single Vehicle Crashes, by Vehicle Type and Initial Point of Impact - State : USA, Year : 2007
Pedalcyclists Killed, by Related Factors - State : USA, Year : 2007

http://www-fars.nhtsa.dot.gov/People/PeoplePedalcyclists.aspx

Interesting charts.

The one thing I like about segregated lanes is that I feel more at ease to go slow. When I'm riding in the midst of traffic, I often feel pressured to keep my speed above 10 miles per hour, which can make steep hills and long distances less enjoyable.

I personally think sharrows are a better option, but if the illusion of safety that lanes provide gets more people riding, perhaps that's a good thing.

I like the sign that say's "Bikes May Use Full Lane." As well as the share the road signs. Hopefully they let drivers know to expect bicycles on the road.

It's a good article, worth reading. I think bike lanes increase safety because they help keep cars and bike segregated. But, as the article points out, the dangers of intersections still remain. The bike lane is great between intersections, but getting out of the lane and into traffic at the intersection usually is the best strategy.

I don't think that it is always necessary or safe as the article points out, to keep motor vehicles and bicycles segregated.

I've got to agree with you that at intersections that it is best to get out with traffic. That way you are more visible. And you can (hopefully) observe turn signals. Granted with the infrequency that some drivers use their turn signals you'd think that they were disabled at the factory. :-(

Bike lanes create a perception (some would say illusion) of safety, because drivers expect cyclists to stay on their side of the white line, and vice versa. Cyclists like the idea, because cars aren't supposed to go there.

The truth is that cars cross the lane at every driveway and intersection. And cyclists need to move to the left edge of the traffic lane at least every now and then because they need to make left turns.

They make traffic situations more complex, by introducing a new. partially segregated stream of traffic, and expecting everyone to blithely share intersections and other crossing areas.

They're useful,and they're a strong encouragement for more folks to ride. Just be careful out there...

Fortunately here in Florida the law says that just because there is a bike lane that bicycles do NOT have to use them. And sadly here in St. Pete more then a few of them are just the shoulder repainted as a bike lane. And I think that we all know what ends up in the shoulder.

Do people really call themselves "Foresterites"? I thought it was a term that other people called them.

No idea, before I read the article I never heard of him/them.

I'm sorry, but I'm not from this country, and I am not familiar with these new term - how you say it, ah - "safty."

-Kurt

Kurt,

Sorry, I dropped the "e" from safety.

Go back to Texico, 'ito. :thumb:

But I use Shell.

-Kurt

Go back to Texico, 'ito. :thumb:

Depending on painted lines for an illusion of safety is gonna make you have a bad day sooner or later.

Yep, I agree with that. They're a good idea on paper but given that roads are only so wide they at best a false sense of safety.

It would be nice IF there was room for a road for cars, a road for bicycles, a road for roller bladers/skaters, etc. But there isn't enough room to make roads for everyone and we'd still have to contend with intersections.

It would be nice IF there was room for a road for cars, a road for bicycles, a road for roller bladers/skaters, etc.

It would be nice...until you have an intersection.

-Kurt

It would be nice...until you have an intersection.

-Kurt

Exactly.

Forester’s opinion is that bike lanes were not devised to keep cyclists safe, but rather to keep them from interfering with car traffic.

Lol, I agree with Forest on that, but there is nothing wrong with making traffic flow efficient. There is a reason why you get traffic congestion when people slowdown (whatever reason: bikes, tractors) to watch the accident on the otherside if the traffic is in moderate/high volume.

It is only an illusion... paint offers no physical protection, and thus no added safety.

However, that said, paint does help define spaces, and drivers are used to "staying between the lines."

BL also indicate that cyclists should use the road, but unfortunately BL also seem to indicate where cyclists are expected to "stay."

Bike lanes allow alert drivers to see there is something special, but it doesn't help the idiot who is HUA!

Do people really call themselves "Foresterites"?NO.


I thought it was a term that other people called them.True and I have only seen it used in BFs by those that hate JF.

Bike lanes are convenient storage areas for broken glass, gravel, wires from steel belted tires, plowed snow, sand (formerly used for traction), etc.

Bike lanes reduce cyclist safety at intersections/driveways and encourage motorist to pass cyclist closer because the line tells them that a close pass is now OK.

The article quoted in the op is really poor:
No safety in numbers... the number of cyclists killed has hovered around 800 for each of the past six years [shouldn't that number be increasing???]

The curb lane at this intersection [where a fatal bike accident occurred] ... the safety claims made for bicycle lanes are unfounded. [A curb lane does not conform to AASHTO standards for a bike lane.]

The author cites an accident involving a commercial truck whose drivers are taught that cyclists are hazards and to tap the horn at them but the problem is definitely bike lanes because there was not one present in this accident. As well as ignoring the fact that trucks have a disproportionate number of bike fatalities where the initial point of contact is the right side.
http://www-fars.nhtsa.dot.gov/People/PeoplePedalcyclists.aspx#ctl00_PageContent_ctlStYrPplPedCyc3_lblTableName

Bike safety is notoriously difficult to study, due to the ever present problem with confounding variables. For instance, let's say there is a road that didn't have a BL, and it had X crashes. BLs are added, and it now has X' crashes. Did the BL cause X to go to X'? Probably yes. However (regardless of whether X > X' or the other way around), we don't know whether more cyclists started riding, whether less experienced cyclists took to that stretch of road, and so on. It's hard to calculate rates unless bicycle traffic counts are conducted both before and after.

That being said, I remember a study that claims BLs provide the greatest increase in relative safety anyway, provided they're well-designed. Wrong-way sidewalk riding, as we might expect, scored the lowest. Of course, it's hard to say to what extent rider experience confounded these results too; however, I will say three things. (1) BLs encourage not-so-experienced riders to hit the street, and realistically are the only way we can increase the number of riders out there who ride as opposed to drive (see what happened in Davis CA for example), (2) BLs, interestingly, put bikes into the collective consciousness of society as a whole, making people consider riding, and (3) once people start riding in BLs, they soon find themselves wanting to go places without BLs, and they take up good riding habits while doing so while pushing for more improvements.

As for the debris problem, I wonder to what extent is it overblown; after all, commuter bikes ought to be able to survive bumpy pavement and such with no problems. BLs also facilitate CAR traffic by making it easier for cars to pass (just stay within the lane, so cars aren't slowed for even a couple of seconds). Anyway, to sum up, well-designed BLs, are IMO a win-win proposition.

The article quoted in the op is really poor:
No safety in numbers... the number of cyclists killed has hovered around 800 for each of the past six years [shouldn't that number be increasing???]


Has the number of cyclists per capita increased? or do cyclists still represent less than a 2% modal share of all transportation?

NO.

True and I have only seen it used in BFs by those that hate JF.

I didn't think so from conversations on Chainguard.

I see the usual mixing of concepts being repeated in this thread.

There are two separate issues that should not be confused, or else people will talk past one another:
1. Pavement space to allow cars to pass cyclists at safe distance without changing lanes
2. Striping and stenciling to delineate separation of traffic modes

One does not imply the other. Adequate pavement space can be provided without the stripe, and stripes are sometimes installed without adequate space. This confounds most discussion about bike lanes.

Both space and striping might improve safety under some circumstances. Unfortunately, there isn't enough good data to verify either claim, because overtaking collisions are too infrequent under scientifically measurable or controlled circumstances.

What is clearer are the everyday operational implications of space and striping. The space allows easier passing, reducing social friction. The striping tends to facilitate or encourage filtering forward on the right by discouraging motorists from moving closer to the curb. Curbside striped bike lanes at intersections can also encourate right hook collisions. Stencils and related ordinances discourage parking. By concentrating automobile traffic to the left, striping also reduces variance in automobile position, increasing the accumulation of blown debris on the right.

What is most unclear is whether the reduction in position variance reduces the chance that an inattentive but straight-traveling driver may rear-end a cyclist on the right. Since this collision type is so rare on roads with wide enough pavement and is difficult to analyze, debate about this possibility is filled with speculation and anecdotes.

There is also a lot of disagreement about the social effects of marking separate space for different traffic modes. Some argue it needlessly stigmatizes cyclists who must leave the striped bike lane for a variety of important reasons including safety and compliance with traffic law. Others argue that it provides endorsement and marketing value to encourage roadway bicycling in a culture where there is much ignorance about the subject and little to no public education effort.

Is this a fair description of both sides of the debate?

I think bike lanes are not a good idea for several reasons already stated. I was up in Boston and Caimbridge recently and met up with BF member and told him I would never ride in the BL I'll take my chances with traffic. a big problem in New England is that the roads were just paths and very narrow lanes abound. There is yet another study proposed for one of our main streets with diagonal parking and someone mentioned BL's now that is just death waiting to happen. a better way is to slow the freak down. On the streeet I mention the traffic would be calmed by bikes taking their rightful place in the lane. If the police enforced the existing laws about speed, crosswalks and bicycle rights to the road things would be better and cheaper. And I don't want to get all the flats I used to get before I took the lane and cowered in the gutter.

Has the number of cyclists per capita increased? or do cyclists still represent less than a 2% modal share of all transportation?

We know that cyclists still represent less then 2% of the modal share of the primary means of work related trips and work related trips account for ~20% of all transportation trips. So the bike modal share of all transportation trips is generally unknown (though Portland has some data on this with numbers as high as 25% IIRC.) I have not seen recent survey for the number of cyclists but the number of bikes sold is increasing and my sense (for Maryland at least) is the bike exposure (number of cyclists X time on bike) has more then doubled over the last several years with near the same crash counts.

With more bike lanes being added across the states and with crash numbers holding relatively steady the only assertion that validates bike lanes are hazardous is that there must be a decrease in the exposure of cyclists. I personally cannot see that as a valid assertion but I have no proof one way or the other.

Why do they use an accident in California at an intersection at the beginning of the article if the article is about bicycle lanes? There is no bicycle lane at an intersection in California, they end 150-200 feet before the intersection. If a car had tried the same maneuver the cyclist did, an article about it would most likely say that the driver was not cited.

We know that cyclists still represent less then 2% of the modal share of the primary means of work related trips and work related trips account for ~20% of all transportation trips. So the bike modal share of all transportation trips is generally unknown (though Portland has some data on this with numbers as high as 25% IIRC.) I have not seen recent survey for the number of cyclists but the number of bikes sold is increasing and my sense (for Maryland at least) is the bike exposure (number of cyclists X time on bike) has more then doubled over the last several years with near the same crash counts.

With more bike lanes being added across the states and with crash numbers holding relatively steady the only assertion that validates bike lanes are hazardous is that there must be a decrease in the exposure of cyclists. I personally cannot see that as a valid assertion but I have no proof one way or the other.

In other words: " ...more bikes are being sold, so therefore more must be ridden, and if the number of collisions is not increasing, there must be some cause... "

OK how about this as a cause and effect answer... the number of MTB type bikes and the amount of offroad riding is increasing. If that is the case, it does point to a type of "underground" "separation of facilities... " Just a thought.

Why do they use an accident in California at an intersection at the beginning of the article if the article is about bicycle lanes? There is no bicycle lane at an intersection in California, they end 150-200 feet before the intersection. If a car had tried the same maneuver the cyclist did, an article about it would most likely say that the driver was not cited.

In my area of Cali, we still have some early design BL's that go right up to the intersection, and they are at some of our area's busiest intersections. I've had issues with motorists, on occasion, trying to force me out of the way while they were making a right hand turn. In these types of BLs, one just has to take special care, and be even more alert for a right hook, especially when trying to pass something like a semi.

In other words: " ...more bikes are being sold, so therefore more must be ridden, and if the number of collisions is not increasing, there must be some cause... "

OK how about this as a cause and effect answer... the number of MTB type bikes and the amount of offroad riding is increasing. If that is the case, it does point to a type of "underground" "separation of facilities... " Just a thought.

It's my understanding that road bike sales in the US soared during Lance Armstrong's recent years of Tour de France victories while MTB sales leveled off or dropped from their peak in the 1990s.

Commuter cycling also seems to be up since the start of the recession and gas price spike. Here in Cary, NC, among what appear to be fairly affluent professionals, it seems to be ideologically motivated. I see lots of commuters riding nice drop-bar road bikes with trunk racks, panniers, and lights - significant investments.

In other words: " ...more bikes are being sold, so therefore more must be ridden, and if the number of collisions is not increasing, there must be some cause... "

OK how about this as a cause and effect answer... the number of MTB type bikes and the amount of offroad riding is increasing. If that is the case, it does point to a type of "underground" "separation of facilities... " Just a thought.

Or how about exposure being the wrong model to describe cause? I look at the bike crash model like a large picnic area with people randomly moving around during a thunderstorm. When the number of people moving around are low increasing the number of people increases the odds of being struck by lightning but there is a point of diminishing returns as further increasing the number of people does not increase the number of lightning strokes.

Almost all crash types are static as if there is some sort of sociological component to keep the road risk factor constant (i.e. risk compensation http://en.wikipedia.org/wiki/Risk_compensation) But all I can really say for sure is the exposure model does not fit the evidence.

(snip) I have not seen recent survey for the number of cyclists but the number of bikes sold is increasing and my sense (for Maryland at least) is the bike exposure (number of cyclists X time on bike) has more then doubled over the last several years with near the same crash counts.

With more bike lanes being added across the states and with crash numbers holding relatively steady the only assertion that validates bike lanes are hazardous is that there must be a decrease in the exposure of cyclists. I personally cannot see that as a valid assertion but I have no proof one way or the other.

For many years, about half of the bike crash deaths accrue with riders who are under 16 years of age. The ratio of children to adult deaths has been changing- skewing toward adults.

A good article looking at this aspect of the changing demographics of cycling can be found here (http://cycledallas.blogspot.com/2009/06/statistics-matter-of-interpretation.html).

(Warning! This blog has been known to blow up cherished false notions! Proceed there at your own risk!)

To quote form that article:


An acquaintance pointed out how bicyclists' deaths have decreased since the advent of more and more segregated facilities. I pointed out my belief that the decline in fatalities was primarily the result of the abandonment of bicycling by children. This graph from the Insurance Institute of Highway Safety shows how the ratio between adult and child fatalities has flipped in the last three decades, and how adult fatalities have continued an upward climb (a roughly 100% increase to 624 per year for a three year average), while child fatalities have declined dramatically (averaged roughly to 80%, or 120 per year for the last three years).

My point, and perhaps The Human Car's point as well, is that there is more afoot than just bike lanes and the number of butts on bikes.

Chicago is full of bike lanes and lots of people use them. I would guess someone must get doored and seriously injured every day there? I personally dislike bike lanes because:

1) You have ride on the edge right next to cars to avoid the door zone
2) Most bike lanes have lots of broken glass, making flats common
3) There is no way to tell if car sees you when you check your mirror. With VC, you see cars making preperations to overtake you far in advance. But one has no such clues with bicycle lanes.

It all depends on the details.

I have to agree big time.

Bike lanes the the right of right turn lanes are a death trap.

Also I've seen some very nice bike lanes, ones that inprove safety for many miles, only to end suddenly at the worst posible place.

One thing on bike lanes and statistics, this is one area where statistics can be misleading to worthless. Bike lanes clearly attract less experienced riders, these are the riders who are more apt to have accidents. Either because of their own mistakes or because they were not experienced enough to expect wrong actions by drivers.

In general I thing bike lanes increase safety, unless riders gain too much of a sense of security and fail to ride carefully.

In my area of Cali, we still have some early design BL's that go right up to the intersection, and they are at some of our area's busiest intersections. I've had issues with motorists, on occasion, trying to force me out of the way while they were making a right hand turn. In these types of BLs, one just has to take special care, and be even more alert for a right hook, especially when trying to pass something like a semi.

I can find plenaty in the Los Angeles area that go right to the intersection, and even more that end much closer than 150 feet from an intersection. Some of them fairly new.

1) You have ride on the edge right next to cars to avoid the door zone

Only if the bike lane is in the door zone, which is an artifact of stupid design. Some aren't.


2) Most bike lanes have lots of broken glass, making flats common

Most here have a little broken glass. Not lots. No more than any other pavement that doesn't have car tires continuously running over it.


3) There is no way to tell if car sees you when you check your mirror. With VC, you see cars making preperations to overtake you far in advance.

With VC, I usually cannot see cars making preparations far in advance, because they are not making preparations far in advance.

They wait until the last minute and either jump lanes or hit the brakes. For all I know, they could be texting as the come up on me.

I think that bike lanes are there because people think they improve safety. The problem is that the whole concept breaks down at every intersection.

(Warning! This blog has been known to blow up cherished false notions! Proceed there at your own risk!)what is a Keri wave?

Or how about exposure being the wrong model to describe cause? I look at the bike crash model like a large picnic area with people randomly moving around during a thunderstorm. When the number of people moving around are low increasing the number of people increases the odds of being struck by lightning but there is a point of diminishing returns as further increasing the number of people does not increase the number of lightning strokes.

Almost all crash types are static as if there is some sort of sociological component to keep the road risk factor constant (i.e. risk compensation http://en.wikipedia.org/wiki/Risk_compensation) But all I can really say for sure is the exposure model does not fit the evidence.

What you mean by an exposure model Barry? Is it that the collision risk is a function of some environmental factors (density, traffic volume, traffic velocity, # conflict points), individual choices (lane position, velocity, contraflow or not), and so on? If there is a feedback effect with number of cyclists, does that contradict an exposure model?



My point, and perhaps The Human Car's point as well, is that there is more afoot than just bike lanes and the number of butts on bikes.

More or less, I concur.

For many years, about half of the bike crash deaths accrue with riders who are under 16 years of age. The ratio of children to adult deaths has been changing- skewing toward adults.

A good article looking at this aspect of the changing demographics of cycling can be found here (http://cycledallas.blogspot.com/2009/06/statistics-matter-of-interpretation.html).

(Warning! This blog has been known to blow up cherished false notions! Proceed there at your own risk!)

To quote form that article:



My point, and perhaps The Human Car's point as well, is that there is more afoot than just bike lanes and the number of butts on bikes.

Good points, but regarding the increased number of adults being killed on bikes... where does experience fit into that picture?

Supposedly a more experienced cyclist should be a safer rider (lessons learned and all that), but the stats seem to be pointing the wrong way.

OK granted age may not equal experience... and we could be looking at older riders just getting back in the saddle... so that may be the governing factor.

One thing to think about is if youth are not getting into cycling, where is the next generation of cycists going to come from???

With VC, I usually cannot see cars making preparations far in advance, because they are not making preparations far in advance.

They wait until the last minute and either jump lanes or hit the brakes. For all I know, they could be texting as the come up on me.

Bingo...

but folks are willing to attribute all sorts of "magic" to VC... of course the same can be said for paint...

bike lanes allow alert drivers to see there is something special, but it doesn't help the idiot who is hua!

hua?

Bike lanes are convenient storage areas for broken glass, gravel, wires from steel belted tires, plowed snow, sand (formerly used for traction), etc.

Exactly and sadly not too far from my home there are several streets with "bike lanes" that are just the shoulder/curb repainted as a bike lane. And there is plenty of debris in the "bike lane."


Bike lanes reduce cyclist safety at intersections/driveways and encourage motorist to pass cyclist closer because the line tells them that a close pass is now OK.

A well designed bike lane should terminate before the intersection, and bicycles should get into the habit of integrating with traffic at intersections. When out riding IF I am the first vehicle at an intersection I take the lane so that hopefully the people coming up behind me knows that there is already someone there in the lane. If I am the second or more vehicle back I position myself where I can see the drivers face in his/her outside driver side rear view mirror. Using the logic that IF I can see them then they can see me.

For many years, about half of the bike crash deaths accrue with riders who are under 16 years of age. The ratio of children to adult deaths has been changing- skewing toward adults.

A good article looking at this aspect of the changing demographics of cycling can be found here (http://cycledallas.blogspot.com/2009/06/statistics-matter-of-interpretation.html).

(Warning! This blog has been known to blow up cherished false notions! Proceed there at your own risk!)

To quote form that article:



My point, and perhaps The Human Car's point as well, is that there is more afoot than just bike lanes and the number of butts on bikes.

Interesting but I doubt the whole US started to build bike lanes in any significant amount in 1975. While Maryland is not on the cutting edge of bike lanes we are not the last kid on the block either and we really did not do anything of significance with bike lanes till 2003 and I'll assert we still don't have anything of significance in terms of bike lanes and where bike crashes occur. In other words the crash stats are still reflecting the same old stuff. Maryland has something like 30,000 miles of roads (excluding interstates) and I doubt we have a 100 miles worth of bike lanes (note we have over 500 miles of wide shoulders.) I'm not sure anything can be gleaned by methodologies in that article till there is at least a 10% saturation of bike lanes on the roads across the US.

I will also note that demographics, road type, crash type all dramatically change if we are talking about fatalities, serious injuries, car/bike crashes or all bike crashes. In Baltimore the 5-15 age group represents about half of all bike/car crashes, 20 years and younger about 75% of all bike/car crashes, (and in all but a few very rural counties kids are overrepresented in bike/car crashes) which at least locally refutes that kids have given up bicycling. Something to note for a tentative theory: when I biked to school in the 70's I had to travel 45mph roads but when I was riding with friends we stayed primary on 25mph roads. And I'll note that nowadays 80% of bike/car crashes happen on 35mph or lower roads and at those speeds a fatality is not likely to happen so tentatively maybe it's just that more adults and less kids that are biking the faster roads (remove the necessity to travel a high speed road (to bike to school) and kids will likely stay on slower roads.)

I'm not sure if I am making a point :p but I strongly feel we need to question how we look and view the world around us especially if we run across evidence that does not support the view point.

What you mean by an exposure model Barry? Is it that the collision risk is a function of some environmental factors (density, traffic volume, traffic velocity, # conflict points), individual choices (lane position, velocity, contraflow or not), and so on? If there is a feedback effect with number of cyclists, does that contradict an exposure model?

In highway safety circles the most often used formula (that I have seen) is: Fatalities / VMT
To "normalize" crash data according to exposure (the exposure model.) If you look at http://www-fars.nhtsa.dot.gov/Main/index.aspx you can look at the different rates (per VMT, Population, Vehicles and Drivers) but what rate correctly states the increase or decrease in highway safety? Well if I was a highway engineer I would like the VMT rate as it shows a large improvement in safety and it makes a good case for more expressways to improve safety. But does a 28% increase in VMT with only a 16% increase in population really show improved safety? Oh boy I feel so much safer now that I have to drive 12% farther to do the same daily activities then I did 14 years ago. The point here is that exposure is not a valid model, not for cars and not for bikes. More butts in cars is not increasing total fatalities and so far evidence points to more butts on bikes does not increase fatalities either.