Rules For Highway Code Rules

In 1964 an American law professor called Fuller wrote a book called the “Morality of Law” which said: all purported legal rules must meet eight minimal conditions in order to count as genuine laws. What I intend to do is look at these principles and see how they might apply to The Highway Code.

Law courts

These are Fuller’s “principles of legality”. The rules must be:

1. Sufficiently general

  • This means that they should be capable of being applied consistently

  • Otherwise everything is decided on a case by case basis

  • A way of looking at this is to do the greatest good for the most people by doing the least harm to the fewest

Certainly the rules in the code seem to me to be reasonably general. If you look at motoring law it is to the best of my knowledge applied reasonably consistently, certainly within a local police forces jurisdiction.

At the end of the day speeding is speeding. How speeders might be caught and brought to book might be another matter. Having a simple clear speeding limit makes it easy to understand and simple to comply with.

2. Publicly promulgated

  • People have to know a rule to be bound by it

  • People should take reasonable steps to the rules to be aware of it

Clearly The Highway Code is available as a document quite cheaply and free online. The DVSA with the Theory Test and ourselves as instructors do all we can to ensure that people are aware of what is expected of them. In fact you might say this is the whole purpose of The Highway Code, so everyone knows what is expected of them.

The laws that make it up are also widely available either online or referred to in The Code and if you look up the abbreviations you will be referred to the appropriate bit of law. If so inclined you can look up the actual Acts themselves.

3. Prospective (i.e., applicable only to future behaviour, not past)

  • If it’s legal now, and you are going to make it illegal it can not be retrospectively

  • You can not make someone libel now for what was legally done in the past

So while The Highway Code is always changing and evolving it is not retrospective. This is the same way that the law of the land is not retrospective.

4. At least minimally clear and intelligible.

  • Is it set our clearly

  • Can you understand it


Part of the process of the code’s evolution is sometimes making things clearer. The recent changes regarding the hierarchy of users does exactly that. Remember that it has always stated that you should “Always give way if that can help to avoid an accident”. All the new changes have mostly been done to make things clearer.

5. Free of contradictions

  • If law contradicts itself how can it be enforced

  • A lot of this will be derived from the other principles.

The Highway Code is brilliant at this. A good part of it is mutually supporting. For example Rule 239 “You MUST ensure you do not hit anyone when you open your door”. Then Rule 152 “Look out for: car doors opening”. It won’t take long to read through and come up with other examples.

The Law

6. Relatively constant, so that they don’t continuously change from day to day.

  • If the law has no certainty how can you keep to it

  • Again as I look these rules or principles they seem to be mutually reinforcing


A quick look at my paper copy of The Highway Code shows its last revision as 2015. The online version will be more up to date with the minor revisions. A quick look at the online version will show 18 updates.

We are due a new version this April. But the changes won’t be massive. We had some stuff recently about smart motorways. A bit more is coming with the hierarchy of road users. But none of this is earth shattering. More often than not any changes are in the wording reflecting changes in the law.

7. Possible to obey

  • No point having a law unless you can obey it

  • Unless of course you are seeking to criminalise a section of the population


I would like to think that it is not only possible to obey The Highway Code but it should be obeyed. Some people will point out that some of it is only advice. The law can not cover every conceivable circumstance. But we can certainly have some principles to guide us.

8. Administered in a way that does not wildly diverge from their obvious or apparent meaning.

  • If a law is applied in such a way that it does not seem just or logical

  • How can we as a people respect the law

Perhaps our biggest protection here is the common good sense of the police force and the judiciary. Fortunately The Highway Code embodies the other 7 principles so the administration of it is quite clear.

policeman signaling

A police officer will use his discretion as to how he deals with a particular situation. I have sometimes heard this referred to as an attitude test with a possible gift voucher depending on the circumstances and attitude. Moral here is to be nice to police officers.

But what about when the devil is in the detail. In number 5 above I quoted rule 152. This as you will see refers to driving in built up areas and quite residential roads at that. On a busy fast moving road can you open your door without looking and just rely on the other driver. So we have a small gap. When rule 239 says give enough room, why do we need rule 152.

car door opening knocking cyclist

I think it is fair to say that the rules arise from need and circumstances. We have some new stuff about smart motorways. We now have the hierarchy of vulnerable road users. Nothing too much has changed from the point of view that we as drivers and driver trainers have a duty to be safe. By expressing what is expected clearly we all know what we need to do.

Fuller argued that together these principles will guarantee that all law will embody certain moral standards of respect, fairness, and predictability that constitute important aspects of the rule of law. I would like to think that The Highway Code meets all these tests.