Tuesday, 12 October 2010

Over 30s Shouldn't Drive

The Institute of Alcohol Studies says[pdf]:
After drinking, the brain works inefficiently, taking longer to receive messages from the eye; processing information becomes more difficult and instructions to the muscles are delayed. Alcohol can slow down reaction time by 10 to 30 per cent.
 If this is a reason to ban drink driving then many over 30s should not be allowed to drive. A research paper entitled "Simple reaction time, duration of driving and sleep deprivation in young versus old automobile drivers" reports that the median reaction time for drivers under 30 was 236ms. If that is increased by 30% we have 306.8ms.

In other words, the law currently assumes that someone whose reaction times are over 306.8ms should not be driving. The problem is that the median reaction time for over 30s is 262ms with a standard deviation of 81ms (the slowest recorded was 448ms). This means that quite a lot of drivers over the age of 30 are driving with reaction times equivalent to being drunk while driving.

Obviously I'm being facetious. But the point is that the law is far too arbitrary. As it stands people are being punished without any evidence that they (as individuals not statistics) are incapable of driving properly.


  1. I think the law is intended to punish voluntarily reducing your ability.

    In the same way it is illegal to drive carelessly, while fiddling with the radio or applying make-up or whatever. It's not that you have passed some incapability threshold, but that by your own actions you have reduced your capability.

  2. I don't see how that justifies the law. If I'm an excellent driver and then drink a bit so now I'm only an average driver why on earth should that allow the police to arrest me and fine me? I'm now no more likely to cause an accident than anyone else.

    It only makes sense if I have fallen below some threshold at which I become too much of a danger to other people.

  3. Because there is no objective grading to determine who are the good drivers?

    Unless you can scientifically award yourself a score for sober another for drunk and a third for a minimum standard, then what you're saying has no meaning.

  4. And equally the arbitrary ideas about drink driving also have no meaning. They're just arbitrary and have no justification as one drunk driver might still be a better driver (ie less accident-prone) than another sober one.

    As I see it, in order to have a liberal society we must be prepared to accept that sometimes people will commit crimes. So too with drink driving. We cannot and should not arrest people for drink driving in the absence of any other proof of poor driving because at that stage they have not committed a crime. Instead people should be arrested and charged only with actual dangerous driving. If being drunk increases the chance of driving dangerously then proper detection and prosecution of dangerous driving would lead people to be more careful about drink driving. That, I think, is how it should be.