What Is a Safe Passing Distance?

I don’t know — in any absolute terms.

I do know that I like the choices 23 Springfield drivers made today while I ran errands in the urban core.

What follows is anecdotal and should not be considered the basis for any decision regarding House Bill 1250 to create a “3-foot law” in Missouri. I urge Carbon Trace readers to check this for themselves and report back in the comments.

I traveled about six miles on my errands today. I was passed by 23 cars (Springfield can be a bit sleepy on a Saturday). I rode on streets such as Fremont, Bennett, Kimbrough, Walnut, and Cherry.

To properly judge my results today, it is necessary to know how I position myself in a lane. My first priority is to ride in the lane along the path of a typical car’s right wheel (an area that usually easy to see on the road). So I’m generally positioned from center to center right in an average lane. In a narrow lane ( eight to ten feet), I position myself in the center area.

Take a look at this picture of a lane I estimate to be about 10 feet wide. This looks like several of the streets I rode today — especially Bennett and Fremont.

passing

That driver’s passing technique looks OK to me. That’s about what I saw today. That appears to me to be about five feet between the car and the bicyclist. The bicyclist, however, is too far to the right for my tastes. I think he needs to be another foot or two to left (about where he appears to be pointing). And if he were so positioned, that car would use the full on-coming lane to pass. That’s how it’s supposed to work — just like the Missouri Driver’s Guide suggests.

Of the 23 cars that passed me today, not one of them passed me closer than (by my estimation) five feet — about what you can see in the picture. Every car used a substantial portion of the on-coming lane to pass me (e.g. the picture above). Eight pulled entirely into the on-coming lane.

Hypothesis: Some drivers in Springfield’s urban core believe that a distance that can be described as “about five feet” is a safe distance to pass a bicyclist.

Question: If true, do you really want the state re-defining “safe” to something less?

I continue to search for a proper study regarding safety defined as a 3-foot minimum passing distance.

Try this for yourself. Report back here. Realize that if you ride farther to the right than I  do that you might find drivers passing you closer than five feet. But I could be wrong. So check it out for yourself.

UPDATE: This question occurred to me: Why would any bicyclist who has ever been passed by a car by as little as three feet (35 mph or faster) ever want THAT to be defined as safe? I’m not getting it.

UPDATE: Read this excellent examination of the “3-foot law” by Keri Caffrey of Commute Orlando. Be sure to take a good look at her graphic illustrating the findings of the video research linked below. She says:

…no matter how much you publicize that law, it is not going to make up for bad lane position. If cyclists ride so far right that motorists can squeeze through, they will. They just can’t help it! Impatience plus opportunity overrides reason, consideration and law. I mean, c’mon, look at the other stuff drivers do that EVERYONE knows is illegal!

UPDATE: Watch this video study of the relationship between lane position and passing distance.

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Comments 16

  1. Lovely Bicycle! wrote:

    I ride int he Boston area. In some neighborhoods, drivers “freak out” and don’t know what to do if I am not cycling all the way on the rightmost edge of the lane. A month or so ago, one woman rolled down her window and yelled “For goodness sake honey, get over on the right where you’re supposed to be so the cars can pass you without killing you!” What do you make of that? I think it’s genuine ignorance of the law, in which case the law should be better publicized.

    Posted 05 Dec 2009 at 3:06 pm
  2. Andy Cline wrote:

    Lovely… Local conditions vary. I’ve had similar things happen to me in Springfield, but not often. And, yes, I do think ignorance in general plays a role — one reason why I don’t want the average driver interpreting what three feet means ;-)

    Posted 05 Dec 2009 at 4:42 pm
  3. MamaVee wrote:

    this is interesting and helpful. Esp for me as a driver. As a biker I get passed veery closely. I’m wide myself ( box is maybe 3 feet wide?) and I am totally too far right. I get passed often about 2 feet. Maybe closer. We have narrow roads too. When cars are parked it’s difficult for cars to pass oncoming cars and no one really wants to slow down even if a huge landscaping truck is half parked in the lane. They def don’t like to slow down if a cyclist is there.

    Lovely and I are in the land of the impatient. As a Born and bred north easterner I understand the feeling all too well and have worked hard at being more patient. ( for me it was a fast walking thing and I hated being slowed down by slow walkers or slow people ordering at the front of the line…. )

    Posted 05 Dec 2009 at 5:03 pm
  4. Steve A wrote:

    I have taught my daughter not to pay any attention to the lane position of any cyclist (or pedestrian or equine) – just make a full lane change when it’s safe and pass. No fuss, no muss. No thinking required. It’s so simple. When we go for driving practice, I have her seek out cyclists so she gets a better feel for it.

    The only times in 2009 that I have been passed with as little as three feet are when I have actively encouraged the motorist to do so (in all such cases, the motorist was going less than 5mph). Mostly, five feet is typical since I ride mostly at the right side of the left tire track in 12 foot wide lanes. I ride there because that is directly in front of where any overtaking driver will be sitting, minimizing any need for peripheral attention. Even a texting driver is MOST likely to notice what is going on DIRECTLY ahead.

    I can’t see how a three foot passing law would change motorist behavior one way or another. People pass in a way they believe safe – unless they’re intentionally harassing someone. IMHO, it is a cyclist’s DUTY to help a motorist make a consistently correct decision on how to pass the cyclist safely. After all, the cyclist will pay the highest price for any motorist error.

    The worst feature of a three foot passing law is it diverts advocacy resources from things that could positively help cyclists.

    Sorry about the long comment, but this IS a big deal.

    Posted 05 Dec 2009 at 6:31 pm
  5. Steve A wrote:

    The very first post on my blog was a case where a motorist passed me with less than three foot clearance. I think you’ll agree it did not represent any danger to me whatsoever, though it WOULD have violated a three foot passing law. I guess it would have violated a five foot law even worse. The website link will take you to that post.

    Posted 05 Dec 2009 at 6:36 pm
  6. Andy Cline wrote:

    Steve… I do worry about a change in driver behavior, but my worry could be unfounded. But here’s my thinking: I fear that drivers will pass closer because they have now been told three feet is safe, i.e. that’s all they have to give us. Speed limits offer an example of sorts of the kind of thinking I’m talking about. A speed limit, as you are well aware, is the absolute fastest you can go under good conditions. But far too many drivers treat it as the speed they have to go, must go, or ought to be able to go.

    Posted 05 Dec 2009 at 11:22 pm
  7. Lovely Bicycle! wrote:

    I agree re the danger of creative interpretations of “3 feet”. But at the same time, 3ft is better than 0ft. Another phenomenon we have in Boston, is that in areas where messenger-style cycling (i.e. reckless, usually fixed gear, weaving in between cars, etc) is popular, the cars are so used to cyclists that they do not seem to think any space at all is necessary. On one particular street (Somerville Ave., for those who are local), I have been “brushed” by a car’s mirror 3 times since July. It was going slowly and the impact was so mild that it did not harm or even dis-balance me in any way – but still!…

    Posted 06 Dec 2009 at 2:24 am
  8. Lovely Bicycle! wrote:

    Oops – The way I phrased that last comment made it sound as if the same car brushed me 3 times. They were different cars; should have said “they were going slowly”.

    Posted 06 Dec 2009 at 2:25 am
  9. Keri wrote:

    I’d much prefer to communicate the cyclist’s right to the lane and a paradigm that motorists must change lanes to pass.

    I’m more than over the 3ft law and the way cyclists mindlessly cling to it. Most close passing results in cyclists trying to share narrow lanes.

    The freak-out described by Lovely Bicycle! is a result of decades of bad laws and browbeating. It’s the cyclist’s version of the “Pigeon Deal.” (Cyclists are expected to stay out of the way or scatter like vermin to make way for cars.)

    Nowhere have I seen it more pronounced than here in Key West. We taught a class this weekend and suffered constant (no exaggeration) abuse for breaking the deal. Oddly enough, Key West may have the highest bicycle mode share in the US.

    Posted 06 Dec 2009 at 7:13 am
  10. danc wrote:

    “‘Safe distance’ is not measured by cold inches, but by circumstances and the variation from perfectly straight driving or riding which may be anticipated from ordinarily careful persons”
    [Stockfisch v Fox Supreme Court of Michigan, 1936] from Mionske, Bob “Bicycling & the Law”, Boulder: Velo Press, 2007 (27)

    Road users must use due care. 3 ft passing law is trying fix some behavior, deficiency, so is the problem with the motorist or the person on bike or both?

    Posted 06 Dec 2009 at 7:22 am
  11. Andy Cline wrote:

    Steve was having posting troubles yesterday. He asked me to post this link:

    http://www.dfwptp.blogspot.com/2009/06/first-post-duty-obligation-courtesy.html

    Posted 06 Dec 2009 at 10:13 am
  12. Cycler wrote:

    Speed has a lot to do with comfortable passing distance. Someone passing me closely but slowly is much more comfortable than someone passing at high relative speed. I think that the 3′ rule is more useful in a situation like Boston where too often people are trying to squeeze by with no clearance. If there is no law requiring safe distance, there is no standard to appeal to if someone buzzes you.

    That said, I’m skeptical that people are going to reduce their safe passing distance in response to this law if they were previously inclined to give more than 3′.

    Posted 07 Dec 2009 at 9:32 am
  13. Andy Cline wrote:

    Cycler… I understand your skepticism re: changing behavior. And, for me, that will probably be true because of my lane positioning. It’s the gutter bunnies who will suffer.

    Posted 07 Dec 2009 at 9:38 am
  14. Alexander wrote:

    it seems like 3 – 5 doesn’t matter so much because you still have to go into the other lane, which means you’re treating cyclists like cars to be passed, which means in these road situations you have people moving at radically different speeds… can a cyclists meet the speed of traffic on these roads?

    Posted 08 Dec 2009 at 12:22 pm
  15. Andy Cline wrote:

    Alex… Downtown I can match speed, but not on most roads. You’re right, I think, about the way most people act — at least hereabouts. So the law is unnecessary. If advocates here really want to advance things, they’d push to codify the language in the Driver’s Guide.

    Posted 08 Dec 2009 at 4:04 pm
  16. Karl McCracken (twitter: @KarlOnSea) wrote:

    I’d agree with you as to the correct position for the bike in the picture – another 18-24 inches out.

    What I’ve found is that you have to be far enough out from the kerb to force the car to cross the centre line of the road. If not, they’ll tend to keep inside the lane they’re sharing with you . . . almost no matter how close this brings them to you!

    Posted 12 Dec 2009 at 3:50 pm