Testing Some Logic

17 November 2014

This morning I tweeted a link to this oft-cited article which explains saccadic masking, with the suggestion that perhaps the explanation of it—the understanding of why that first look isn’t enough, even though you absolutely think it is—ought to be a part of mandatory training for drivers.

Back came the response, “How about a compulsory driving [sic] test for all cyclists as well?”

Well, why not?

The basic logic

First, lets take a look at the logic that gives rise to the question in the first place. If we ignore the thinking of “cyclists should have to take a test because I hate cyclists” (which is kind of coherent in a dumb way, but is hardly an acceptable basis for policy), the logic can only be this:

Cyclists, like drivers, use the road. Everyone who uses the road should be required to take the same test.

OK. Makes sense. But let’s see where that logic gets us.

Road users include not just drivers and cyclists, but also equestrians, type 3 mobility scooter users and pedestrians. You’ll be needing them to take the test, too.

Pedestrians? Oh, but they have pavements, right? Let’s refine our logic:

Cyclists, like drivers, use the carriageway. Everyone who uses the carriageway should be required to take the same test.

But you still don’t get to play the “pedestrians don’t use the carriageway” card. They do. They cross carriageway, and where there is no pavement they walk in the carriageway. They have a right to do so.

Maybe you want to chip in with some quirky reasoning as to why pedestrians should be exempt as road users. That’s ok. It doesn’t really matter what it is: we’ve still got equestrians and mobility scooter users.

Let’s consider bridleways. They’re highways. We don’t have tests for people to use them, because there’s not sufficient need. Collisions are few, and their consequences generally minor. Equestrians, pedestrians and cyclists are mixing broadly safely. Do we need testing here?

Let’s consider footpaths and pavements. They’re highways. We don’t have tests for people to use them, because there’s not sufficient need. Collisions are few, and their consequences generally minor. Mobility scooter users, pedestrians and—in the case of shared paths—cyclists are mixing broadly safely. Do we need testing here?

Let’s consider the cycleways of the Netherlands. They’re highways. They don’t have tests for people to use them, because there’s not sufficient need. Collisions are few, and their consequences generally minor. Cyclists, mobility scooter users and others are mixing broadly safely. Do they need testing there?

The available tools

We have to consider the purposes of each element of the regulation of traffic. What does each element allow us to achieve?

Signage allows us to guide people to behave in certain ways. It means we can influence everyone at a location, with immediacy.

Rules allow us to formally define expected behaviour. They mean we can communicate expectations in a universally understood manner.

Legislation allows us to punish problematic behaviour after it has occurred. It means we can create deterrents, and deal with people whose behaviour needs correcting.

Testing allows us to require some proof of recognition of expected behaviour. It means we can prevent certain people from doing certain things if they have not demonstrated sufficient competence.

So, when it comes to the carriageway, we have signage for everyone, rules for everyone, legislation for everyone, and testing only for the users of mechanically powered vehicles.

Also note, of course, that signage, rules and legislation vary across the modes: for instance, there are no lighting regulations for pedestrians or equestrians, and no speed limits for pedestrians, equestrians or cyclists. Everything here is a broadly sliding scale.

So why the inconsistency?

A stark illustration

No clearer illustration is required than a collision yesterday which claimed the lives of five people. Such is the energy in a car crash.

Of course there are examples of fatalities in collisions involving no mechanically powered vehicles. But they are rare, because the energy is so much lower. Multiple fatalities in one collision are practically unheard of (at least, I’ve never heard of such an occurrence).

The risk that powered vehicles present to others is orders of magnitude greater than that presented by unpowered vehicles.

It’s that potential to do harm that’s the issue. We already have signage, rules, legislation and testing that recognise this: if you want to drive an HGV you’ll need a specific test and you’ll be subject to different speed limits and restrictions.

That potential to do harm is why we try to make sure that people know the rules prior to taking control of the vehicle.

That potential to do harm is why relying on legislation alone is insufficient. The scale of harm is such that risking collisions and then applying punishment is simply not good enough.

The acid test

To test the logic, one can think of the other extreme to a road: a shopping mall. People move chaotically; often colliding. They have no testing, no legislation, no rules, and—other than in exceptional cases—no signage.

But it’s fine. It’s fine because bumping into someone has very low potential to harm. The potential still exists: it’s quite possible to bump into someone and cause them to fall and suffer a fatal head injury. But that potential is so low that it demands no regulation at all.

And this is the underpinning of it: Our default position is, rightly, one of freedom of movement and a lack of regulation. What we do regulate is the potential to do harm.

And that’s why testing is not related to the use of the roads but to the use of vehicles, and the ability to control the energy that they amass.


  1. rdrf 17 November 2014 2:58pm #

    I think you are dignifying this nonsense by making a rational argument Bez.

    The only answer is: “Yes,, but first we have to be able to threaten other people’s lives (and hurt or kill them) as much as drivers do.” The fact is that the “driving test” is there as one of the pseudo-regulations – along with 3rd party insurance, VED etc. It’s part of the problem.

    If it isn’t , why do most drivers not do what they did when they passed the “test”? Any benefits are neutralised by the sense of entitlement they get

    • Alan Braggins 17 November 2014 3:07pm #


      How about cycle licences are optional, but if you choose to get one, you get a free firearms licence with it if you pass a firearms safety test?

      • rdrf 17 November 2014 9:30pm #

        Alan Braggins:
        firearms licences (plus subsidised guns) after “taking a test” and providing you promise to wear a bullet proof vest (= seat belt) when using your gun.

    • Bez 17 November 2014 3:11pm #

      I agree, but to say “first we have to be able to threaten other people as much as drivers do” is to draw an arbitrary line somewhere between the potential for harm presented by bicycles and cars. Which, of course, has been done. And indeed arbitrary lines have to be drawn all over the place, not just in this matter but with speed limits and so on.

      But the point is that these lines need to be drawn based on an understanding of the logic and of the relative risk, otherwise who’d to say that drawing the line of testing above bicycles and below cars is the right one? I personally like dignifying nonsense by rationalising it, because it’s generally the most robust way of demonstrating it for what it is.

      Common sense is so often wrong, and so often worth testing 🙂

      And, yes, of course I agree that the lax implementation of testing and regulation is part of the problem. I’s agree that it’s too easy to obtain—let alone retain—a licence, and too easy to step into an especially dangerous vehicle having obtained one.

  2. mrmo 18 November 2014 3:53pm #

    a very very simple question, If licencing, Insurance, and number plates work as a way of controlling drivers and preventing accidents. Why do so many drivers ignore their training, and have accidents?
    Maybe we need to look at why cars are sold that can break the speedlimit, why we sell cars with so many distractions included, why should driving be seen as a right and a licence never revoked permanently regardless of behaviour.

  3. Ernie Marples (@ErnieMarples) 21 November 2014 1:56pm #

    It’s much too easy for an offending driver to retain his licence when he shouldn’t. That goes for weak sentencing by courts and the nonsense of self-policing declarations of fitness to DVLA.

    Take this case of two young women who were killed in Glasgow in December 2010 while walking on the pavement. http://www.bbc.co.uk/news/uk-scotland-glasgow-west-24821758

    The driver had blacked out at the wheel. That’s something which, I suppose, could strike anyone, but this guy had a history. He had suffered 6 blackouts in the previous three years, lied about them on his DVLA declaration to renew his HGV licence, and had no insurance.

    Four years on, this guy has yet to be prosecuted.
    (While there was a charge of causing deaths by driving while uninsured, this was abandoned after a UK Supreme Court ruling in a similar case.)

    Thankfully his licence has been withdrawn but only after he killed two people.

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