Is there a liberal case for not raising the speed limit?

When Philip Hammond announced that he was in favour of raising the motorway speed limit to 80 mph, my instinctive reaction was “That's stupid”. The immediate reaction was based on his reasons for doing it, the most prominently quoted of which, at the beginning at least, was that so many drivers on motorways exceed the limit anyway, that we may as well raise it. On that basis I look forward to him repealing the law on using mobile phones in cars and also voting for the legalisation of cannabis. No? No, I didn't think so.

His other key reason makes marginally more sense in that both cars and roads have become safer since the limit was set. Both fatalities and serious accidents have reduced significantly and steadily over a long period, and so it makes sense to look at whether the limit is still appropriate. So I thought I should, rather than nurturing my own prejudices, look at what the liberal arguments are for and against raising the speed limit.

One of the issues I think is that the argument for raising the speed limit is quite simple, whereas the argument against has to be put in a more complex way. The argument for is that people should not be prevented from doing what they want to do unless it harms someone else. If it does harm someone else then in order to come to a decision on what to do, you have to consider the relative harms of restricting the rights of person A, the doer, or person B, the done to. The main issues you have to deal with are that people get killed and that there is a cost to the environment. The figure for last year, 2010, is that, with our modern safer cars and roads we managed to kill 118 people on our motorways. Even if you accept the argument that speed kills (lots of people don't – but more of that later) presumably those 118 were killed by a probable maximum of 113 perpetrators (there were 113 accidents). These figures are from the DfT. One might say that the other millions of motorists should not be prevented from doing what they want because of the consequences caused by a very small number of people. On the environmental issue, you either ignore it or you try to come up with an argument that says the gains in time saved etc are worth the environmental costs. I don't plan to spend much time on the environmental argument, because I'd like to concentrate on the human angle and the rights angle.

To look at the other side – the case for not raising the speed limit, I think there are two key issues. First of all the principle of freedom is clear – if I want to restrict other people's freedom I need a good reason. Secondly, the reasons should be based on evidence rather than doctrine. Problems arise of course when the evidence is equivocal. Then the skills of weighing it and interpreting it come to the fore.

So, first of all, let us visit the evidence. The debate is about freedom versus life and limb (leaving the environment aside for the moment). My right to travel at what speed I like against other people's right to remain alive and unharmed. So the evidence must show how many people are killed and injured, how many of those accidents are preventable, and whose fault they are.

In terms of deaths and injuries on our roads, the trend has been firmly downwards for many years. To take a sample year pretty much at random, in 1990 5217 people were killed and 60,000 injured seriously on our roads. In 2010 the corresponding figures were 1850 and 20803. (Note: 1850 is a revision in the latest version of the 2010 figures released by the DfT.) The collection of these figures has been challenged in that a study in 2006 found discrepancies in police reporting and hospital admissions, suggesting that the method of police reporting, on which the official figures are based, was reducing the actual number. This is now acknowledged in the DfT's annual summary. But the reporting effect is minimal. So, yes, our roads are a lot safer than they were. Does that mean they are safe enough? In the announcement something was made of the fact that our roads are among the safest in Europe. That claim has been examined by fullfact.org and shown to be broadly correct, if a little disingenuous. Now, that is not an evidential claim. It's a comparative claim, and it is open to us to say “So what?” I'm not that impressed by the fact that our roads are safer than Romania's. I'd rather they were safer still. The fact that our roads are safer than other people's means nothing when we still managed to kill nearly 2000 people on them last year. So I'm discounting that comparison for the purpose of deciding what a liberal response should be.

Part of the context of this is that motorway driving is considerably safer than driving on other roads. Motorways make up less than 1% of our road network, yet take 19% of the traffic. Even so, 5% of last year's fatalities happened on motorways. So by comparison with other roads, they are very safe. But that still does not necessarily mean that they are safe enough. The next thing to check is whether speed is a contributory factor in deaths and injuries on the motorways. The evidence here needs to be divided into two parts. Does speed contribute to accidents happening? And does speed contribute to the severity of the consequences if an accident does happen? The evidence for the first question is that it makes a limited difference. There is a problem here in that the safety of cars has increased in such a way that people get the impression that they're perfectly safe to drive at high speeds because the car will protect them. Road, tyre and braking technology have also increased to the point where it is much more rare for a driver to lose control of a car at high speed. But that does not mean that it does not happen. A significant number of deaths are in single vehicle collisions – in other words, a vehicle colliding with a tree or failing to negotiate a bend. I have no data for the proportion of such accidents on motorways as opposed to other roads. It is almost certainly a lot less, but equally certainly it does happen. The safety of new cars and roads is only relative. The higher the speed, the longer the reaction distance needs to be to allow for safe braking even with new technology. And driving at least two seconds apart is an activity that seems to have escaped a lot of British drivers. (I will come back to driving habits later.) Overall the WHO estimate that 1 km/h decrease in travelling speed would lead to a 2–3% reduction in road crashes.

Looking at the consequences of accidents the evidence is much stronger. Many studies demonstrate that increases in speed cause great increases in severity of impact. The WHO paper referred to above estimates “For car occupants in a crash with an impact speed of 80 km/h, the likelihood of death is 20 times what it would have been at an impact speed of 30 km/h.”

It seems clear from this evidence then that raising the speed limit from 70 to 80 would cause a small increase in accidents and a significant increase in the proportion of fatalities and serious injuries resulting from such accidents. This is admitted by the DfT, whose initial analysis indicates a 1% increase in deaths, according to the Guardian.

This still leaves open the question of what we should do. Millions of motorists used our motorways in 2010. Only 113 of them, at most, killed somebody, and only 668 caused serious injuries (injuring 798 people). Does a few people getting it wrong give us reason to restrict everybody's liberty? I think that there is an argument for that. Here we leave evidence behind and move into the realm of consequence, principle and practice.

A lot of people assume that those who cause fatal and serious accidents are different. They are idiots, bad drivers, unlike the rest of us who are good drivers. But there is little indication that those who cause such accidents really are different – they are not boy racers, they are not serial offenders, they are not all travelling at egregious speeds that nobody sensible would ever consider. They are ordinary drivers, just like most of the rest of us, but their luck ran out. We might more legitimately think that some are a bit sillier than most of us, but even if we assume that, can we assume that the way we behave has no effect on them? We have in this country a culture of driving badly. We do not recognise it as such, but if you consider the common driving behaviour, it is difficult to escape that conclusion. Most people do not think of speeding as a crime, far from it. Large numbers of people think that they have a right to break the speed limit. This applies to people who regard themselves as law abiding in every other way. I once said to a room full of pensioners that we are all law breakers. There was instant disapproval. I asked for a show of hands of people who had never broken the speed limit. “Oh, that's not the same thing”, they said. I have one eye on Question Time as I'm writing this. The usual audience – the kind of solid upstanding citizens who are actually interested in politics. Good people, who think through and about issues. If I asked in that studio right now how many drivers could, hand on heart, say they had never broken the speed limit, I doubt that any would be able to do so. It has become routine; it is part of our driving culture. We assume that speeding is OK, which is one reason why Philip Hammond is raising the issue – he assumes it too. In his case, I think he has an idea that, given that people are travelling at 80 now, if you raise the speed limit to 80, they will continue to travel at that speed. I think their perception is not that they are travelling at 80, but that they are travelling at speed limit plus 10%. If the limit is raised, then the limit plus 10% will be raised commensurately.

Another indication of the kind of driving culture we have in this country is the way use our car horns. The meaning of sounding a horn, in the Highway Code, is “I am here”. The meaning of the horn, as used by most of us, is “I am angry with you”. The overall culture is one of a general selfishness, and a great carelessness. We work on the basis that we can get into our cars and then not pay attention till we get to our destination. We do not value awareness of what is going on around us. This is why so many of us think it's OK to use a mobile while we drive. “1/5 of UK motorists admit accessing social networking sites on their mobile phone while driving.” and many more will phone or text with. Many of us will travel at the fastest speed we can, or for the law abiding, at the stated speed limit pretty much regardless of the weather, road or traffic conditions. Varying our speed to suit the conditions does not come naturally to many of us. The culture will not change because the speed limit is raised. All it will do is assimilate the new limit into its way of thinking. (Work carried out in the United States confirms this.)

My general point here is that the driving culture is made by all of us. When people get killed on the roads most of us can quite rightly say we did not kill anyone. But it is wrong to draw from that the conclusion that we can escape responsibility for the cumulative effect of the things that we do. We determine and preserve the culture that enables the few who drive so carelessly and at such speeds that they do kill people. The speed limit as such isn't the problem: it's the way we drive that results in so many deaths and so many serious injuries. But the speed limit is a factor, because it is part of the equation people use to determine the speed at which they will drive. I doubt that the way we drive is going to change (I would like it to, very much, but I am not optimistic) so any decision made about speed limits has to take that into account.

In summary, my argument is:
- evidence shows that increasing speed causes small increases in the likelihood of accidents happening, and significant increases in the consequences of accidents, in terms of deaths and serious injuries.
- life has value, although we drive as if it does not - although the bulk of motorists are not directly responsible for deaths or injuries, the majority of us maintain a culture in which people are encouraged to drive selfishly and carelessly
- it can therefore be justified, on a liberal basis, to restrict everybody's freedom to drive at speed, in order to allow as many people as possible the freedom to live.

A more positive liberal approach would be to work on educating people about good habits of responsible driving, awareness, and the need to protect the environment. An even more liberal approach would be to get them out of their cars and onto more frequent and more reasonably priced trains and buses. But I only meant to discuss the speed limit.