Passing Laws

All cyclists have experienced a close pass from another vehicle. It’s an uncomfortable experience and the larger vehicles can cause major issues due to the turbulent air that they throw off. Cyclists need to be given lots of space, we need to move around road hazards such as pot holes and we aren’t surrounded by metal.

Some states in the US and a few countries have a specific passing law. Usually 3ft or 1m space that overtaking vehicles must give to cyclists. In the UK we don’t have a specific law and the highway code suggests that you should give as much space as you would a car, I have commented on that before.

I see some problems with passing laws

  • How do you measure the distance?
  • Larger differences in speed require larger passing distances.

The DFT name the space a cyclist requires the dynamic envelope. The Cycle Infrastructure Design (CID), Department for Transport Local Transport Note 2/08, October 2008. Section 2.2.2 states that the dynamic envelope of a cyclist on the road may be taken as 1 meter. As the name suggests, the dynamic envelope changes depending on the situation but the basics of it is the required space a cyclists needs to keep in motion. Corrections are made to avoid hazards and to keep balance.

When a vehicle overtakes a cyclist, the space they should leave you is in addition to the dynamic envelope. The DFT recommend that in addition to the dynamic envelope of 1m, cars passing at 30mph should add another 1.5m when passing. In total that equates to 2.5m from the cyclist (this distances is measured from the wheel of the cyclist to the edge of the car). How many drivers do we see passing cyclists at such a distance?
The DFT recommends that larger vehicles (buses, HGVs) should give a total of over 5m when passing a cyclist at 30mph.

The distances which drivers give cyclists needs to be increased in situations like hills, cyclists will be going at a much lower speed and keeping a straight line can be more strenuous. In these cases more space will be needed.
To cover one of my concerns, as the difference in speeds increases then more space is required, if a cyclist is traveling at 10mph and a car passes at 3ft at 60mph then the turbulent air will push them off their course and could well blow them over if they are not prepared for it.

How can we measure passing distances whilst on the road? This is always going to be a problem, one persons 3ft is another persons 2ft and being on a bicycle the two will feel very different, the two will probably be very similar when you are surrounded by metal. In the case of reporting it to the police or speaking to the driver about it, this will be the same old situation which we are used to, your word against theirs.
I have a ‘litmus’ test for close passes, I’m normally aware of when they will happen, I stick my arm out as if i was indicating, if i feel a vehicle brush against my arm then I know the pass is about to be too close and I can move over to the left a little bit to give me more space. My arm is a little under 3ft so if I can touch your vehicle as you pass me then you are too close. I’ve noticed so far that this gives the drivers a panic and they either stop their over take or they move further out, it has the added bonus of making you look like you are turning right.

The guidelines for passing distances that the DFT state are well over what any laws are in other countries and anything that is proposed in the UK. I can’t see a 3ft law being brought into the UK whilst a DFT recommended 30mph passing distance is over 2.5x bigger. The minimum 20mph passing distance that the DFT recommends is 2 meters. Because of this I’m mentally against any passing laws that state 3ft as the minimum.

6 thoughts on “Passing Laws

  1. Whilst I appreciate the need to give us space I’ve never quite understood how they can say “allow as much space as you would with a motorvehicle” which means nought really as you rarely see cars passing each other (when overtaking for example) with a whole lanes space. I rarely see passes where the driver goes over to the opposite side of the road when passing. They are probably slightly rarer then the close passes with most people (90-95%) falling into the “meh” category where they haven’t passed close enough for me to need to yell at them or haven’t left me so much space I smile and give a thank you wave 🙂

  2. I see a 1 metre/3 ft passing law as being something useful for rural highway and urban arterial road application. If someone passes at 2 ft at low speed in a busy downtown, I don’t care much… but a fast pass on an open road is very worrisome!

    A 1 metre passing law was passed recently in the Canadian province of Nova Scotia without really any noise at all. It’s been proposed for Ontario, our most populous province, but it didn’t go anywhere. I wouldn’t be surprised if our Québec province adopts one, they are probably the most bike friendly province, they had the first city with separated bike lanes in their downtown (Montréal), and is criss-crossed with thousands of kilometres of rural Route-Verte (“green route” in English) cycle path routes for cycle tourists.

    As for enforcement, just wait til I finish my overtake distance sensor project (-: I’ll get ‘er done once I get back from holiday in late September and go full speed on it and go get some overtaking distance research done!

    1. I can’t wait to see how your project works out!

      There are pros and cons to having passing laws, As the DFT in the UK have recognised, you can’t have a single distance for all cases, it really does depend on the situation.

  3. I found this information very useful, thank you so much for posting this (and many others I haven’t thanked you for) I have given this information to Cycle Action Auckland who I hope can use it to help gain traction on safety issues.
    I Hope you are recovering quickly, the plus about being a cyclist is you are fitter than the average cager and will recover faster

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