A Miss is as Good as a Mile


This “three foot” thing has me thinking.

Long time ago, I drove ships for a living. First in the Navy and then in the US Merchant Marine. Ships are funny things, they don’t turn “on a dime”, rather when the rudder is shifted and the wheel held at a certain number of degrees to the left or right, it may take 1/4 of a mile or more before any change in direction is made. The heavier the ship is, the slower it responds to rudder changes.

On a “voyage” of three months I stood watch with a new third mate who didn’t quite understand why things were the way they were. He had earned his pilot’s license for the upper and lower Mississippi.

There, boats and barges routinely pass each other within 100 feet or less, sometimes within ten feet. Running aground, while not common, was not all that unusual and, in most cases, a reversal of the props, then full forward and back again,  would free the ship of it’s muddy bottom grounding. Extreme cases required a tow from a tug boat, but that was considered part of the job and since the bottom shifted constantly, not a job killer. No damage done.

Back at sea, when two ships approach each other, careful calculations (called the Closest Point of Approach or CPA) are made as to how close they are predicted to come within each other.  Radio contact is made between the ships and they  compare each others CPA calculations. The autopilots are disengaged and the ships are  steered by hand. Captains have standing orders that when a CPA is calculated to be less than a certain amount, usually a mile, he is to be called so that he can make the course change since it is his butt on the line if things go wrong.

The air is  tense, people’s voices rise in pitch and volume, then  . . . the ships pass and things go back to normal. The captain retires from the bridge, the autopilot is turned on.

This whole procedure seemed very odd to the new third mate and one night he asked me why everybody freaked out the way they did. He had a good point.

My answer was to him was that when driving a ship across an ocean there are not too many ways to screw it up, but one way was to have a collision at sea, maybe 500 or 1000 miles from land. People would quite logically say, “How the hell could such a thing happen?” yet it has happened. A former President made a career of it happening.

When you are out in the ocean, you may not see a ship for a week or more, yet when you finally do, it invariably is going to cross your charted path and then the above described activity should take place. And when it doesn’t, then there is a collision. It is hard to believe, but it happens. That’s a job killer. Everybody gets fired — except our former President who becomes a hero due his daddy doing damage control for him before he landed.

So what does this story have to do with bicycles? Well, how many feet do you need to be passed by a car to “feel comfortable” ? Six inches? Three feet? Six feet? 5,280 feet? It’s worth thinking about.

Years ago, when I was taught to stay out of the way of cars by hugging the side of the road, cars didn’t move over the double-yellow and “shared the road” with me by passing within a foot or less. Am I dead because of those tens of thousands of close passes, even by semis doing 55? For me, at that time, just like the third mate/pilot, a miss was a good as a mile.

Yet I know it would have been nice to be passed with a wider berth and I like about three feet or more. And I guess that is why tension builds up within me when passed “too close.”

12 replies
  1. Kevin Love
    Kevin Love says:

    Eric asked: “…how many feet do you need to be passed by a car to ‘feel comfortable’ ?”

    Kevin’s answer:
    As a cyclist, I take up about a metre measured from elbow to elbow. Add another 1/2 metre “swerve room” on each side to avoid potholes, etc, and I need two metres of road space to operate.

    Motor vehicles are legally allowed to be 2.6 metres wide. I presume that this is a North American standard, because nobody measures them when crossing the border from the USA into Ontario.

    Motor vehicles also need 1/2 metre of “swerve room” on either side of them to operate safely. Add it all up and the absolute minimum lane width to share a lane with a motor vehicle is 5.6 metres. Converted to Imperial units this is a little over 18 feet and four inches. There are very few roads that wide. So cyclists should absolutely never allow a motor vehicle to pass them in the same lane.

    The Dutch standard is a minimum of 2.5 metres for a unidirectional bicycle road, with a minimum separation from a road on which motor vehicles are allowed of 1.5 metres.

    In practice, the distances are frequently much greater than these minimums. For example, see:


    I’ll give an example of the road that I personally am most comfortable cycling on in another post to avoid the robot killing my writing.

    • Diana
      Diana says:

      Flat, staight, wide, well protected from pedestrians and motorists…I guess it would be safe, up until you died of boredom.

      • Kevin Love
        Kevin Love says:

        Or until I got to work. I really prefer commuting to be boring. Boring is good.

        All I want when going to work is to be part of the cycling hordes who are also going to work. I can experience the fresh air and sunshine (or rain; I’ve got good rain kit). I can say “hello” when I go by someone that I know. Then I get to work safely and on time. Which is the whole purpose of the trip in the first place.

        Those who want entertainment can look at the artwork or read the plaques explaining the history of the site. Which is quite interesting.

        In the 1950’s and 60’s there was a proposal to turn Toronto into an American-style city by constructing a series of segregated automobile expressways. There was a huge citizen battle led by people whose neighbourhoods would have been destroyed. Fortunately, the whole scheme was defeated.

        The monoliths are the remnants of a partially-completed elevated automobile expressway.

  2. Will
    Will says:

    Kind of puuts the 3 foot rule into perspective. Many of us know that a pass at 2 feet and 5 mph overtaking isn’t as scary as a 4 foot pass at 40 mph over. Much like a river barge compared to open ocean.

    Who came up with 3 feet? There any science behind it, or did someone just pick a number and say “thats good enough”

    • Keri
      Keri says:

      It was stupid to codify a distance. 3ft is inadequate at higher speeds, or for large vehicles at any speed, but I will let a motorist squeeze past me with less than 3ft a low speed differential.

      Good question about who came up with it. I’m not sure exactly where it came from. A few states have tried to pass laws with larger passing clearances but have failed… unhelpful minimum precedent.

      The recent Maryland 3ft law takes the cake for idiotic:

      • Will
        Will says:

        I would love to see a study on wind effects of high speed vehicles and see how far they are at certain speeds. If you’ve ever been stopped on the side of the road you know how much the wind from a truck can rock a car. Science can prove how inadequate 3 feet can be.

        • Keri
          Keri says:

          There is a chart on wind blast in one of Wayne’s papers
          It might be the “How Wide?” paper, but I’m too lazy to look it up.

          I highly recommend anyone interested in cycling advocacy read Wayne’s critiques, BTW. He’s done an excellent job of exposing the BS foisted upon us by the pseudo-science-for-hire hacks and the DOTs that contract them.

  3. Mike
    Mike says:

    I don’t want to get hung up on your mention of presidents, but which one(s) are you talking about? Wikipedia says that JFK’s PT boat was hit by a Japanese destroyer and that Douglas MacArthur said he should have been court-martialed for letting that happen. Is this what you’re talking about?

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