Of Advocacy and Stasis

To follow up on yesterday’s post, I want to address the whole discussion thing. I concluded my post with a short list suggesting that there are certain types of bicyclists that I’m willing to discuss advocacy with and certain types that, well, not so much. Now’s a good time to discuss stasis theory.

Before one can discuss anything intelligently with another person (with whom one disagrees) the two interlocutors must reach stasis — a situation in which they understand and accept the source(s) of their disagreement. Situations that are out of stasis are not truly discussable. The best example of that in our culture is the abortion issue. Pro-life? Pro-choice? Not only are those positions out of stasis, the parties do not want to achieve stasis because there’s a danger in it: once you agree about that with which you disagree, a chance is opened that you might be — horrors! — persuaded.

So what I was hinting at is this: Much of bicycle advocacy is out of stasis and is, therefore, not discussable.

What could we agree upon to reach stasis? Allow me to suggest a short list (certainly not exhaustive; and I certainly expect my readers to add to it):

  1. The rules of safe movement ought not be violated.

OK, so, yeah, that’s a really short list. And I am not suggesting — as I noted in the qualification above — that this list is exhaustive.

I want to begin the discussion here with the general agreement that the rules of safe movement ought not be violated — by planners, by engineers, by motorists, by bicyclists, by anyone.

If you believe that it is OK to violate the rules of safe movement, then we have nothing to discuss. The reason: Rules create the system of traffic. Without rules there is no system. So disagreement with the rules of safe movement is absurd.

Now that may sound like I’m simply trying to slam-dunk the discussion before it ever begins :-) And, in a sense, that is true. But I’m not playing a rhetorical trick here. I am simply pointing out that in order to advocate for certain types of bicycle infrastructure, one must be willing to violate the rules of safe movement. If so, I’m going to point it out and ask: why?

There are many answers to why (e.g. increase participation). I have yet to hear one that’s persuasive. Or, one might not have thought it through far enough to see that what one is asking for is a death zone.

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Comments 49

  1. Mighk Wilson wrote:

    Might I amend your list a bit Andy? It’s still one item (though I suppose it could be split into two).

    “The rules of safe movement ought not be violated _or_ increased on number.”

    Every rule is also a point of failure when someone violates it, so increasing the number of rules increases points of failure. Advocates of edge-style or pedestrian-style bikeways are effectively calling for a new rule (or two) of movement:

    For edge facilities (bike lanes), add: If you’re a motorist, yield to vehicles on your right (and in your blind spot) when turning right, and yield to on-coming vehicles you can’t see because they’re screened by other vehicles.

    For bi-directional sidepaths and cycle-tracks, add: Yield to vehicle traffic traveling against the flow of normal vehicular movement.

    Complex systems work better with fewer rules.

    Posted 15 May 2013 at 7:30 am
  2. Mighk Wilson wrote:

    Sorry, “…increased IN number.”

    Posted 15 May 2013 at 7:35 am
  3. Ian Brett Cooper wrote:

    I agree with the concept of the ‘death zone’. I think perhaps we need to define it. I suggest it exists on every road from the point at which the average car’s right fender edge is, all the way to the right hand side curb – any cyclist or pedestrian in this zone is far more likely to be sideswiped or hit by vehicles straying too far right. At an intersection, I suggest it exists even farther right, to the rightmost edge of the sidewalk, due to the risk of turning collisions with gutter cyclists and fearful cyclists using on the sidewalk.

    Posted 15 May 2013 at 7:45 am
  4. Ian Brett Cooper wrote:

    Sorry – meant to post on the Enjoy the Death Zone page.

    Posted 15 May 2013 at 7:47 am
  5. Khal Spencer wrote:

    Mighk makes a major point that has been studied exhaustively in high risk systems such as chemical plants, nuclear power plants, etc. High reliability systems are complex beasts in their own right, but attempt to avoid situations that are failure prone and put in redundant countermeasures at failure points Of course these redundant systems are themselves points of failure.

    The politicization of these systems makes them ugly..

    Posted 15 May 2013 at 7:56 am
  6. Robert wrote:


    The rule of safe movement could also be interpreted to include speed differential. That’s one of the principles behind the “85th percentile” rule that most of our speed limits are based upon. Speed differential and it’s relationship to crashes is very well accepted in traffic engineering.

    Someone pedaling 12 MPH in a 65 MPH lane may also be violated the “rule of safe movement” if you care to include speed differential into your rule.

    Just a thought

    Posted 15 May 2013 at 8:56 am
  7. Andy Cline wrote:

    Mighk… Yes! I want additions and amendments and clarifications to the list.

    Robert… I think we may be able to agree on the general concept re: speed. You won’t find me on a 65 mph road :-) But then such roads are typically limited-access highways and closed to bicyclists by law (in most state, I believe).

    Posted 15 May 2013 at 9:18 am
  8. Khal Spencer wrote:

    Robert makes a point. Rules of safe movement are in the eye of the beholder to some degree, Chipseal’s laments notwithstanding. One reason for the minimum speed rule on superhighways, and the requirement to use flashers if going slower, is that there is a greater probability of a crash when extreme speed mismatches are involved and the severity of these crashes are high. This is the reason sharrows are not recommended for roads with speeds >35 mph.

    Rules of safe movement are only one part of safety. If you ask a traffic engineer what he would do if he had all the money and space in the world, he/she would probably grade separate all different traffic, i.e., pedestrians, bicyclists, and motorists to avoid those rare but catastrophic crashes. Intersections of these systems would be minimized and designed to optimize engineered and administrative controls such as lines of sight and good traffic control devices.

    Those of us in this weird hazard analysis world often use, in its most simple form, a hazard matrix to look at this stuff. One axis is severity and one is frequency. Low-low is green, high-high is red, and intermediates are yellow. A lot of thought goes into calculating where something goes on the matrix. For example, a high speed rural overtaking crash might be rare but of extreme severity. A nuclear plant meltdown might be extremely rare but of extreme severity. What resources do you put into designing a countermeasure?

    Total grade separation is likely a pipe dream in any built environment in the US, since the dollar and political costs would be prohibitive. So what we end up with are half-measures such as partially grade separated “protected bike lanes” that protect cyclists until, as Schubert would say, the point of impact. Typically, the countermeasures required in these more complicated, semi-separated systems are either incomplete or cumbersome due to cost or level of service compromises.

    As far as data, I’m not happy with most of what I see on bike lists. Too many people confuse hypothesis with proof, and don’t look at the right data. One guy who I thought got it right was the Brit who did the paper on helmet use and lane position vs. lateral overtaking distance. Not that I am compelled to not wear a helmet, but he made the point that the bulk of the probability distribution was irrelevant. It was only the low probability extreme tail of “zero to negative passing distance” that mattered, because it is the rare but catastrophic low probability event that kills you.

    We need to have a very long seminar on all this stuff. Anyone for setting up a session at the next TRB conference?

    Posted 15 May 2013 at 9:30 am
  9. Steve A wrote:

    Y’all forget that on occasion 65mph roads are the ONLY way to get from here to there thanks to our traffic engineering paradigm.

    Posted 15 May 2013 at 10:09 am
  10. Steve A wrote:

    Khal – in Texas, minimum speeds only apply when so posted. Texas is not unusual in that regard.

    Posted 15 May 2013 at 10:12 am
  11. marc wrote:

    New rules are even worse when they are exceptionary rules to existing rules. People understand the basic rules. And from this understanding they develop expectations of how things should move and what to expect and what not to expect. They lookout for and make adjustments(poor word choice) to avoid having failure with something they are to expect. When you allow something that is not to be expected to happen you set people up for failure. One could argue that bikelanes should go everywhere and the unexpected should now be the expected and all drivers must operate with a state of hyper vigilance and anxiety. That of course is a horrible idea it would make trips by automobiles and bicycles more nerve racking then ever. It would also increase the fatigue on all road users from the excess stress. That fatigue would result in less vigilance or errors in judgement. The results would be disastrous.

    Posted 15 May 2013 at 10:27 am
  12. Mighk Wilson wrote:

    I say speed differential is a red herring. It only truly applies to freeways and rural highways. I don’t hear about bikeway advocates calling for cycle tracks and bike boxes on rural highways.

    Driver expectations are radically different on freeways and rural highways compared to urban and suburban streets. We don’t expect to yield to pedestrians, stop for transit buses, deal with opposing left turns, etc., on freeways, and very little on rural highways.

    Even so, cyclists routinely ride on rural highways without incident, and the few crashes that do are virtually all due to driver impairment or distraction, not to the speed differential itself.

    If speed differential was at all significant we’d have very clear signals that that is so. Heinrich’s Triangle tells us that for every fatality there would be roughly 30 injuries and 300 close calls. What would the key characteristic be for a speed differential close call? Squealing brakes behind the cyclist. In over 150,000 miles of cycling I’ve heard that sound exactly ONCE. And I was stopped at a red light at the time.

    Posted 15 May 2013 at 10:37 am
  13. Khal Spencer wrote:

    I used the speed mismatch as an example of a rule of safe movement, not because anyone is calling for cycletracks on rural highways. Frankly, as far as I can tell, rural cyclists don’t exist for Streetsblog et al.

    Cyclists can use the Interstates in New Mexico except where posted otherwise. The speed limits are 75 mph and cyclists are required to use the shoulder, not the lane. In urban areas with a lot of onramps and offramps, cycling the Interstates is prohibited. Fortunately, one has other options.

    Disagree on the Heinrich’s triangle application. In rural areas, most cyclists travel without incident indeed. Overtaking crashes are very rare but usually catastrophic precisely because of the high speed limits, which was part of my earlier point. Plus, its not obvious to me the triangle** works here as it was postulated in an industrial accident setting when there were far more types of accidents and near misses than we are talking about and even in an industrial setting, records are not perfect. Here, a near miss is a miss (typically a buzz) and a hit is a hit. I suspect if we tabulated buzzing incidents, one might be able to build a triangle, but who has such data? Perhaps the basic theory works here, i.e., that the bad accidents and buzzes are following indicators of bad practice, i.e., careless driving, drowsiness, DWI, etc.

    ** http://www.nsc.org/safetyhealth/Pages/Examiningthefoundation1011.aspx#.UZO_k3egwqM

    Posted 15 May 2013 at 11:07 am
  14. Khal Spencer wrote:

    Something here.

    Posted 15 May 2013 at 11:28 am
  15. Mighk Wilson wrote:


    It was was Robert’s insertion of speed differential that I took issue with, not your commentary on it.

    I have no problem with sidepaths along rural highways, because opportunities for conflicts are very low.

    It’s in the urban and suburban environments that bikeway advocates insist on adding unnecessary complexity to an already complex system in order to “fix” a very minor problem. Overtaking crashes in urban areas are virtually all sideswipe crashes and have little to do with speed differential.

    I agree that Heinrich’s is not a perfect fit, especially in rural conditions. We probably can’t use the use the 1/30/300 ratios, but my experience of 150,000 miles (most of which has been urban and suburban) with only a single incident of squealing brakes is still pertinent to the urban/suburban risk for overtaking due to speed differential. I’m sure other long-time cyclists have similar experience.

    Posted 15 May 2013 at 11:39 am
  16. Khal Spencer wrote:

    If one wanted to construct a Heinrich Triangle for rural highways, one needs to tabulate frequencies of all of the major and minor accidents and near misses and their frequency. The “industrial setting” would be the rural highway and speed would be only one of the characteristics of the workplace. Head on crashes between cars and rear end hits on cyclists would be high severity, low frequency events at the top of the triangle. Run off the road crashes, deer hits, near misses, putting the right wheels over the centerline or fog line, etc., would be lesser severity events. One has to properly define the setting and the range of accidents, not focus on one accident type alone to use the triangle. Not sure anyone has tried this with rural highways.

    Plus, as some recent students of safety have pointed out, Heinrich put most of the blame for accidents on behavior, hence the use of the triangle for behavior based safety. A lot of current thinking is to avoid workplace traps that either encourage accidents or that do not have built in defenses against recognized human error. Here is where we can study modern “bicycle infrastructure”. Does it ignore or encourage known human errors? Do these designs have defense in depth against forseeable error?

    Sorry post so many things, but I started thinking about this while riding to work this morning.

    Posted 15 May 2013 at 11:40 am
  17. Khal Spencer wrote:

    Hi, Mighk. I think we are in substantial agreement, even if we keep talking about it.

    Posted 15 May 2013 at 11:41 am
  18. robert wrote:

    First – I so don’t want to get into a pissing contest and I am loving the nature of this conversation so far. I have been guilty of writing things on here that were taken as an opening salvo when they weren’t intended to be. Please understand that this message below is not antagonistic.

    I’m not sure that I agree that speed differential is primarily a factor on rural highways. Consider the speed differential between a bicyclist pedaling 10 MPH and someone traveling 50 MPH on an urban arterial.*** That’s a 40 MPH difference.

    Traffic Engineers routinely move speed limits by 5-10 MPH in order to avoid speed differentials between the speed that most people are driving on a stretch of road and what speed a stickler for the posted limit would drive. Regardless of what we think about speed differential, no one can deny that it isn’t accepted as a cause of traffic crashes by traffic professionals. For that reason, I think Andy should consider it in his criteria even if it doesn’t help the normal VC argument.

    I also don’t think that there is any point in discussing the frequency of “near misses.” One person’s “buzz” may not even be noticed by another bicyclist.

    I also don’t know how relevant it is to discuss our own personnel experience being how we are just one example. Mighk points out that he has bicycled 150,000 miles and yet there are others who perhaps only bicycled a few miles before being killed from behind.

    This is the last bicyclist that I know of killed in my area. She was hit from behind, no doubt speed differential played a role, combined with inattention (as pointed out earlier). Who knows how many miles she rode prior to being killed? Was it 150,000 like Mighk or was it 1500?


    ***The way we’ve been designing our cities for the past 50 years, I’m not sure that there is much of a difference between urban arterials and rural highways.

    Posted 15 May 2013 at 12:08 pm
  19. Khal Spencer wrote:

    Robert–we have some urban arterials in Albuquerque with very high speeds. Paseo del Norte has a 50 or 55 mph speed limit. I don’t think anyone even bicycles on it, but recently a bicyclist was killed when a motorist lost control of her car while allegedly “working traffic”, went over an embankment, and travelled far enough offroad to kill a bicyclist cycling a nearby sidepath. High speed urban arterials need to be controlled carefully. This one is not. Neither are the careless motorists.

    There is a visual going around the ped world that tells us that a pedestrian hit by a car at 20 mph stands a low chance of being killed while one hit at 40 mph stands a high chance of being killed. Speed of a crash is a well known contributor to severity. Its as simple as


    In a crash, a lot of that kinetic energy is transformed into deformation, i.e., an inelastic collision. If the deformation is your rib cage, it sucks to be you.

    I don’t think anyone here wants to get hung up on speed alone. Its one of many variables that gets stirred into the pot of traffic safety, and speed can be managed. I routinely ride on high speed rural highways, some with no shoulder or a shitty one**, so I am taking the lane. My concern is not the speed, but whether the motorist I am sharing the road with is drunk, fatigued, late for work, or on the smart phone.

    Lets all keep the rubber side down and the foam on the beer stein up!

    ** http://www.labikes.blogspot.com/2013/05/new-mexico-to-cyclists-well-at-least-we.html

    Posted 15 May 2013 at 12:26 pm
  20. Robert wrote:

    Khal: “My concern is not the speed, but whether the motorist I am sharing the road with is drunk, fatigued, late for work, or on the smart phone.”

    That’s the thing about “taking the lane.” It’s a wonderful way to control the behavior of people who are paying attention. It also puts you right in the way of someone who isn’t.

    Besides the kinetic energy, speed also lessons the margin of error for a motorist who isn’t fully concentrating on the task at hand

    Posted 15 May 2013 at 1:24 pm
  21. RANTWICK wrote:

    I have really enjoyed your last two posts. I am one of those riders you want to have beer with, I think. I ride my bike a lot. Safely. I pretty much stick to those rules of safe movement you speak of.

    I have lost any appetite I ever had for the debate, or even discussion, of what should be done by or for anybody else on a bicycle. Riding my bike is what should be done. That is all. Is that selfish, or just what you’ve been jonesing for too?

    Posted 15 May 2013 at 1:29 pm
  22. Khal Spencer wrote:

    “Taking the lane: It’s a wonderful way to control the behavior of people who are paying attention.”

    Someone needs to cast that into a bronze plaque and mount it on the wall.

    Posted 15 May 2013 at 3:35 pm
  23. Khal Spencer wrote:

    Actually, taking the lane on a narrow, twisty mountain road is probably very safe. You don’t get very many motorists who are not paying attention on NM-4 heading through the Jemez Mountains. They would be wrapped around a tree or hanging over the cliff. Another advantage? Its out of range of cell phone towers!

    I think it is the so-called “safe” roads that are dangerous. Counter-intuitive? Maybe not. Safe roads and separated bike facilities perhaps breed a sort of complacency.

    Posted 15 May 2013 at 3:41 pm
  24. Andy Cline wrote:

    Rantwick … Yes. Just ride. Why can’t we all just ride? Or drive? Or whatever? :-)

    Posted 15 May 2013 at 4:38 pm
  25. Khal Spencer wrote:

    Back to what we might agree on. My short list.

    1. The rules of safe movement shall not be violated. This applies to administrative actions (traffic law) or by the design of the built environment (roadway design).
    2. Addition or subtraction to existing rules of safe movement will not be done without a rational hazard analysis and mitigation of additional risk entailed.
    3. A “reasonable person” above the age of X (TBD) can, with a baseline level of training appropriate to the reasonable person, navigate the built environment on a bicycle.
    4. Rules of operation shall be designed to be safely compatible with all vehicles and pedestrian activity that is expected in the built environment.
    5. Rigorous hazard analysis and engineering design, not feelgood politics, will guide design.

    Posted 15 May 2013 at 5:02 pm
  26. Andy Cline wrote:

    Khal … Nice start. I plan to continue this discussion over more prots in the near future.

    Posted 15 May 2013 at 5:26 pm
  27. marc wrote:

    Was speed diferential the only factor in the accident example or was it lane positioning Was the person hit directly from behind while taking the lane by the speeding car or where they hit by the right wheel or right head light side of the vehicle. If the latter was the case they were then not in the drivers focus area and the speed differential could have been corrected by the driver of the motor vehicle before the driver of the bicycle was hit. see the following link http://floridabicycle.org/wp-content/uploads/2012/10/cone_of_focus-463×600.png In other words was the cyclist in focus area 1 or outside of it.

    Posted 15 May 2013 at 7:52 pm
  28. Khal Spencer wrote:

    Oh, Lord, don’t give me more of this. Being hit directly from behind is as good as being hit by the right headlight. This is another case of hypothesis being conflated with fact. If something is far enough in the road to be hit with the right headlight, its stretching credibility to think it would be different if hit by the middle of the car. Let’s have some peer reviewed data.

    Asking a cyclist to ride in the middle of US 70 in 70 mph traffic and expecting a different outcome than riding in the right tire track is tiresome.

    Posted 15 May 2013 at 8:15 pm
  29. marc wrote:

    The point is this I’m suggesting that had the person been in the left tire track they would have been seen 12 car lengths back or more. According to most State DOT a safe following distance is one car length per every 10mphs so you can stop if the other person stops. So the driver sees the cyclist and now has time to stop. At a certain speed this might no longer work possibly at 70mph on a highway.

    Posted 16 May 2013 at 5:34 am
  30. Khal Spencer wrote:

    Looking at John Schubert’s visual and taking it at face value, a cyclist riding in the right tire track or even on the edge of the lane will be in a motorist’s Primary Focus Area (PFA) at more than four car lengths distance, even assuming the driver is only focussing dead ahead instead of scanning. Therefore according to that visual, one does not have to be riding in the middle of the lane to be in the PFA. At 70 mph and assuming a cyclist at 15 mph, four car lengths is well inside a second from being either passed or hit, so if the cyclist is not seen by then, he or she is dead meat. So riding in the middle of the lane may not add any benefit, but it certainly adds a potential risk (see post #20).

    So as an LCI, I would not risk my life’s savings from a lawsuit telling someone to ride in the middle of a lane on a 70 mph highway. Or even a 60 mph highway. I might even consider it criminal negligence to so recommend, unless I see plenty of peer-reviewed safety studies demonstrating I am wrong. Conjecture, even accompanied by video or nice diagrams, constitutes hypothesis, not proof. Unfortunately, too much of that is going around in cycling circles. Let’s stick to what we know. That’s why, at least in New Mexico, all of the major cycling organizations including BCNM have pilloried the State Dept. of Transportation for turning our roadway shoulders into death zones.

    Posted 16 May 2013 at 9:16 am
  31. Khal Spencer wrote:

    Also, before I forget. The one car length per 10 mph following distance for safety assumes vehicles travelling at similar speeds; it assumes a certain reaction time in a human when the vehicle travelling ahead of you at a similar speed does something out of the ordinary. It is not entirely relevant here because the closing times are already much shorter; with a delta-V of 60 mph, for example, its 88 ft/sec.

    Posted 16 May 2013 at 9:18 am
  32. Mighk Wilson wrote:

    The rules of movement are context-dependent. They become more important as the system increases in complexity. Conflating low-to-moderate-speed urban and suburban conditions with high-speed rural or freeway conditions is not at all helpful.

    I seriously doubt William Phelps Eno would have been inspired to write the first traffic codes if he’d lived his entire life on a farm in southern Indiana. No, it was the chaos of New York City that drove him.

    Rural highways and freeway need fewer rules to govern them because they have either fewer users or fewer inherent conflicts. “Violating” a rule for urban streets may not be a problem on a rural road. So a sidepath works fine, and even that rural cyclist who insists on riding against traffic “so I can see the cars coming” is at relatively low risk.

    But when we get into the urban and suburban environments, with much higher numbers of users, conflict types and conflict points, violating or adding rules becomes a real problem. It requires all users to increase both their vigilance and training.

    Posted 16 May 2013 at 10:32 am
  33. Khal Spencer wrote:

    Adding to Mighk’s post. The conflicts in rural operation are fewer and the users are fewer. Also, the problems are different. Operational complexity is probably the main problem in the built environment. Roadway monotony, high motor vehicle speeds, poor pavement conditions, DWI, and driver fatigue are among the rural issues. There is even a web site or three about it.


    To do justice to cyclists, we need to understand the different needs of the cyclist in the built vs. rural environment and address their risks specifically, rather than with one size fits all solutions.

    For example, in a city, an overtaking crash may happen between a 15 mph cyclist and a 30 mph motorist. In a rural environment, its 15 mph vs. 55 mph. Hence the risk of grave injury or death is much higher regardless of the frequency. Lane control is critical in the built environment as a countermeasure to turning and crossing crashes. It is critical in the rural environment on a mountain road to control overtaking errors. So we need to understand the context as well as the jargon.

    Posted 16 May 2013 at 11:10 am
  34. Mighk Wilson wrote:

    Lane control is also critical for countering urban and suburban overtaking crashes, as the vast majority of those are sideswipes due to squeeze passes.
    Something I’ve noted in looking at bike lane crashes locally: most of the overtaking crashes with bike lanes involve a curving roadway, motorist intoxication, or hit & run (which implies intoxication).

    Posted 16 May 2013 at 11:28 am
  35. Khal Spencer wrote:

    We have a bike lane on Diamond Drive on a long sweeping curve. It gives me and our Chief of Police the willies for exactly that reason, Mighk.

    Posted 16 May 2013 at 11:29 am
  36. Khal Spencer wrote:

    Actually, squeeze passes are a major problem on rural secondary roads like Old Rt. 66 and NM Rt 4. These have narrow shoulders (or no shoulders) so controlling a motorist’s passing behavior is critical–from both directions. Two cyclists here recently barely avoided a head on crash with a motorist passing another motorist and the cyclists were the oncoming traffic. I don’t know if they were controlling the oncoming lane or riding close to the edge, though.

    Posted 16 May 2013 at 11:34 am
  37. Robert wrote:


    How do you know that these crashes wouldn’t have also occurred if the person was taking the lane? In other word: how do you know that the person just wasnt paying attention versus purposely made a decision to pass when there wasnt room?

    Posted 16 May 2013 at 4:43 pm
  38. Khal Spencer wrote:

    Playing chicken with oncoming traffic is great sport in Northern New Mexico. Perhaps its cultural.

    Posted 16 May 2013 at 5:38 pm
  39. Mighk Wilson wrote:


    First, I’m making this argument based on urban and suburban conditions, not rural. I think there’s a serious problem, especially now with smart phones and other new distractions, on rural roads, especially ones that are flat and straight, where drivers can think they can afford to let their attention drop. Expectations and attentiveness are, as I’ve noted before, completely different in urban and suburban environments; you can’t take your eyes off the road for more than a couple seconds without consequence.

    As to my argument that most involve intentional passing, it’s reasonably inferred from a number of observations. The most important is this: close passes are an excellent indicator of the risk for a sideswipe. Those who ride the edge (as I used to) experience lots of close passes. A close pass is the same driver error as a sideswipe, just without the impact.

    Anyone who uses lane control will tell you it greatly reduces close passes, and the only lane control crash I’ve heard of involved a motorist who fell asleep at the wheel. (Not exactly something that paint can remedy.)

    Most of the overtaking crash reports I’ve seen (not including night-time and oddball ones) involve sideswipes.

    Lastly, just work the numbers. Let’s say that one-in-a-thousand drivers is so inattentive that he or she would simply run into an unseen cyclist. I’ll estimate I’ve been using lane control for at least 20,000 urban/suburban miles (likely much higher). At 12 mph that’s a 5-minute mile. Let’s say I get passed by 1 car per minute (that should be way low). That works out to 100,000 passes. So one-in-a-thousand highly inattentive drivers means 100 hit from behind incidents, just for me alone. Then add the hundreds of other lane controlling cyclists out there. If lane control makes us subject to such dangerous inattention, we should be hearing about those crashes all the time.

    Posted 17 May 2013 at 6:32 am
  40. Khal Spencer wrote:

    If lane control was THAT dangerous, we wouldn’t be here to have the discussion.

    My concern is that with increasing numbers of driver distractions to choose from, the safety of lane control will not be the same as it was when cars were just cars. Not sure we have trend data to test that hypothesis, though. Anyone know if we do?

    Posted 17 May 2013 at 7:18 am
  41. Mighk Wilson wrote:


    I did a crash typing study back in 1993 & 1994, the another in 2003 & 2004. I saw no change in the proportion of overtaking crashes. I’m hoping to do another study soon to see how we’re doing with yet another decade of increasing distraction.

    Posted 17 May 2013 at 7:25 am
  42. Khal Spencer wrote:

    Hi Mighk. Can I find those studies in the literature? This is interesting, given the plethora of distracting stuff that has come out in the last decade.

    Posted 17 May 2013 at 8:42 am
  43. Mighk Wilson wrote:

    My earlier study wasn’t published in any way; the latter one is on our website at http://www.metroplanorlando.com/plans/bicycle-and-pedestrian-program/spot-improvement-form/

    I’ll go through my old data to get you the comparison.

    Posted 17 May 2013 at 8:47 am
  44. Mighk Wilson wrote:

    From my 1993/1994 and 2003/2004 data: daytime crashes only (we’ve long had problems with unlit cyclists)

    All overtaking
    93/94 = 10.8%
    03/04 = 5.6%

    Misjudged passing space
    93/94 = 3.8%
    03/04 = 2.3%

    Cyclist swerved
    93/94 = 1.4%
    03/04 = 1.2%

    Other overtaking
    93/94 = 5.6%
    03/04 = 2.1%

    In the 90s we had lots of miles of narrow two-lane formerly-rural roads being over-run with suburban development, and that’s where most of the overtaking crashes were happening. Today most of those roads have been widened to four and six lanes. We also did add some bike lanes during that period, but probably not enough to matter. Since 2006 we’ve had at least 20 overtaking crashes involving cyclists in bike lanes, but I don’t yet know how that compares to non-bike-lane roads.

    While cell phones were getting to be fairly common by 2003/04, they were virtually non-existent in ’93/’94.

    Posted 17 May 2013 at 9:34 am
  45. Robert wrote:


    With all due respect, your answers didn’t seem very compelling.

    First, I think using yourself as a sample size (which you’ve done twice) is hardly scientific. I know you haven’t claimed its scientific but I can tell that you use it a lot and you mix it right in with the data. I’ll give you an example: I drink a lot of diet soda and haven’t gotten cancer. Therefore – diet soda doesn’t cause cancer. While we may or may not be inclined to believe that, everyone can recognize that using a sample size that small is meaningless. That’s an equal comparison to your 150,000 mile claim.

    Second, I’m sure you didn’t mean to make it sound as if you’ve literally only heard of one bicyclist who was taking the lane and hit from behind. I posted a video of one on this website just last week.

    Third: what you call a sideswipe could have been someone who was going to be hit regardless of where in the lane they were. Being hit by the right fender doesn’t mean the motorist saw them and was trying to pass. Fact is, that’s where most bicyclists ride so it makes sense that most overtaking crashes would be a right of center impact. ESPECIALLY if the driver saw them at the last second and swerved to try to avoid them.

    Fourth: this is very anecdotal on my part….most drivers say “I didn’t see him” after a crash and not “I saw them but tried to pass.” Do people just lie after killing someone? Perhaps. Truthfully, I have no idea what drivers say most but it seems like that’s the line that I hear when reading fatality stories.

    Unless I’m not understanding, the arguments you present only support your claim if the person is inclined to believe your theory.

    And I have and do “take the lane.” I know how’ effective it can be IF the drivers are paying attention. I also suspect that if someone isn’t paying attention you’ve placed yourself in a position where a driver can’t avoid you even if they see you in the last couple of seconds.

    Posted 17 May 2013 at 10:27 am
  46. Khal Spencer wrote:

    Its quite easy to argue around in circles. The best we have is the data we can put together. As Mighk’s post indicates, its sometimes difficult to interpret these data because the experiments are not well controlled. For example, in #44 we see that road design has changed and the prevalence of cell phone use has changed.

    To some degree, all traffic management is hostage to engineers and professionals taking their best educated guesses as to what will be the safest thing to do. In the case of bicycling, we know that to an aware motorist, it is good to be visible and therefore in the motorist’s line of sight. What would be good to see would be overtaking crash rates as a function of cyclist position, all other things being equal.

    But all other things are not equal. Ian Walker, for example, comments that his study of helmet wearing and rider position vs. lateral overtaking distance may have results heavily influenced by the type of roads he experimented on.

    As I keep saying, let’s not constantly get into poorly defined fights over poorly defined systems. We really need to learn from each other, and to help each other obtain good data. Hopefully, someone who is dispassionate can get funding to do some better controlled studies. I do worry about some of the recent studies that have been published by folks who have a huge axe to grind. Advocacy research and dispassionate science are not synonyms.

    Finally, I’ve not seen any data indicating cycling, on a per hour basis, is more dangerous than driving a car. The Internet makes it easy to believe that we are all being mowed down out there. The US has a high fatal rate in road crashes, period, but cycling isn’t UNsafe. Let’s not terrorize the public into not bicycling because we constantly are trying to improve it. What’s that expression: The perfect is the enemy of the good.

    Posted 17 May 2013 at 11:50 am
  47. Khal Spencer wrote:

    Oh, I forgot to add the link to Ian’s study.


    Posted 17 May 2013 at 11:53 am
  48. Robert wrote:

    I agree, Khal. I wasn’t trying to argue. More like trying to figure out what’s really being proven by the research shown.

    Posted 17 May 2013 at 12:04 pm
  49. Khal Spencer wrote:

    Hi, Robert. Was not accusing you of being unpleasant. I’m just worried that we are all driving in a heavy fog.

    Posted 17 May 2013 at 4:52 pm