How would you measure the safety of private motor vehicle travel?
Let’s agree to focus on fatalities. Serious injuries are also important, but all the points I am going to make hold equally as well for injuries as for fatalities.Probably the silliest way to measure road fatalities is per vehicle. Our current rate is 5.5 per 100,000 motor vehicles. This rate has been dropping steadily for decades (for instance it was 43 in 1980) not only because road safety has been improving (it has), but because there are more cars per person. In 1950, the whole nuclear family were killed in their FJ Holden. These days, Mum, Dad and the kids share two or even four cars and spread the same total fatality risk across these cars.
The most common measure is fatalities per head. The number of road fatalities per 100,000 people in Australia in 2012 was 6.1. By way of contrast, the suicide rate was 10.0 per 100,000. This measure is a little strange when one considers that it was way lower in 1914. Why was it lower in 1914? Are we really doing worse 100 years later? No, it is because hardly anyone travelled by private motor vehicle in 1914. They travelled by train or horse and buggy, which is way safer. All of which proves (to me at least) that the 6.1 per 100,000 figure is not a valid measure of the safety of road travel.
What we need is a measure which standardises fatalities by motor vehicle usage, and the most obvious measure of motor vehicle usage is kms travelled. This takes account of both the number of cars and of our increasing propensity to use them for short trips
Here is a question. How many fatalities are there (on average) per billion kilometres travelled? A billion kms is equivalent to travelling 25,000 times around the Earth. Stop reading now and think about your best guess.
You may not believe the answer. On average there are only five point seven fatalities per billion kms. How far would you need to drive to have an even money chance of dying? About 160 million kms. This is a little more than the distance from the Earth to the Sun. We are talking interplanetary distances here! Most people will not drive one million kms in their life time.
In 1975 the fatality rate per billion kms was 35.5 so the present rate of 5.7 is a drastic improvement. The chance of dying has reduced from almost no bloody chance to almost no bloody chance divided by 6. Driving a motor vehicle a short distance is just incredibly safe. If you only did it once we would really not worry about it. It’s just too small a risk to consider.
The problem is that you will not drive one km in your lifetime. You will probably drive half a million. So you take (and impose on others) a really, really, tiny, negligible risk many, many times. And even then, your overall risk of being involved in a fatality in your lifetime is low (around 1 in 300).
As a species, we are poor at assessing and responding to risk. Very small risks of terrible outcomes challenge our intuition and make us behave inconsistently. While we voluntarily subject ourselves to a chance of road death every single day, we simultaneously over-estimate the risk and support rather draconian penalties on individuals who increase their risk in specific ways.
I think that there is a lot of inconsistency in our attitudes to road trauma risk and the legal sanctions we impose to limit this risk. We seem to lack a coherent framework. Here are two principles that I think are hard to argue against.
The first principle is that the only sensible measure of the risk a person imposes on the community is their total risk of causing a fatality over their lifetime. (It is up to you if you want to include their own life in this or only the lives of others).
A reasonable reference figure for the total risk would be about 0.28%. This corresponds to the current rate of 1300 accidents per 23 million citizens multiplied by a 50 year driving career. We might express this as 28 per 10,000 people – just to make it a nicer number.
The second principle is that every citizen should be entitled to an equal allocation of this lifetime risk. Everyone gets a lifetime allocation of 28. If you don’t want to use it all, then more power to you. Some people will not even drive (though they will be driver around by others). But if you want a risk much more than 28 the state will start to sanction you.
Of course, we might want to reduce this allocation over time if community standards changed. And we might also include a maximum yearly limit of say 2. Anyway, for the sake of argument let’s take 28 as the lifetime figure.
I can also market my new framework with a catchy title: Vision 28. Road management authorities love this kind of thing…but more on this towards the end of the article.
If you accept the two principles behind Vision 28, and if you do not then you should think very carefully why, then the moral and legal landscape looks very different. Here is a personal example.
I drive around 12,000 kms per year. I actually take the train to work. Most of my 12,000 kms come from a single and completely discretionary source.
You see, I bought a holiday house last year around 75 kms from Melbourne. I go there probably 60 times per year – often just to work in an alternative environment to my office. The driving adds up to 9000 kms per year. So my unilateral decision to use a holiday house for pure pleasure has increased my yearly travel for 3000 to 12000 kms – and multiplied my road fatality risk by a factor of 4. To date, not a single person has chided me for the irresponsibility of this decision.
On the other hand, if I drive at 0.06 on one single occasion, I will perhaps double my risk on that trip alone. If it was a one off misjudgment, then my total yearly risk will be increased hardly at all. If I drive at this level 10% of the time (which would make me a social pariah) my yearly risk increases by 10%. This is equivalent to increasing my travel from 12000 to 13200 kms. Yet, if caught I am caught once at 0.06, I will lose my license and be popularly branded a bloody idiot.
Occasionally driving over the BAC limit does not have much effect on your total yearly or lifetime risk. This is simply not a matter of debate. It does not make you a bloody idiot at all. Driving like an idiot makes you an idiot.
You see there is probably no plausible driving behaviour that would quadruple my total risk short of driving pissed every single time I drive. But I have quadrupled my risk with the holiday house with nary a comment.
With Vision 28, managing risk becomes much more considered than crude uniform BAC and speed limits. Instead, limits can be tailored to circumstance and individual driver skills, and total kilometres driven can also be rationed.
If you think this is administratively impossible, you are probably correct right now. But in 25 years from now, all our cars will be GPS monitored and you will need to breathalyse yourself and insert your electronic license to start your engine.
The point is the state will know exactly who you are (your age and driving record), how intoxicated you are, what road you are driving on and how fast (and how far) you are going. We could calculate the risk for every km traveled. You could get a yearly running summary of you risk allocation usage – like you mobile phone usage indicator
If you really did not want a completely free system, the car could impose a personally tailored BAC and indeed speed limit. Drivers of the lowest age-specific risk with the best driving records would be cut more slack in speed and BAC limits than say younger drivers who had an accident in their first month.
And if you think it is outrageous to let some people drive faster and at higher BAC’s than others, we already have this system now. Older drivers can drive at a full 0.05 higher than P-plate drivers and 20km/h faster than learner drivers (though it is not usually expressed this way). If it makes sense to place extra limits on those with higher risk (the young), it is pretty hard to argue that it is wrong to place weaker limits on those with lower risk. In fact, it is oxymoronic to do so.
Those who have been in an accident could expect a revised assessment of their risk and consequently lower speed and BAC limits. Their lifetime risk up to that point could also be retrospectively recalcualted. Currently, you can have as many accidents as you like and you will probably face no serious legal sanctions. Your speed and BAC limits will be the same as mine. The worst consequence will be higher insurance premiums.
I would expect a pretty hysterical reaction from the current managers of road safety to such ideas. That is because they have been captured by a notion that you might not have heard of – Vision Zero.
The core principle of Vision zero is that ‘Life and health can never be exchanged for other benefits ..’ that ‘Human life and health are paramount and take priority over mobility and other objectives of the road traffic system.’ But these quotes are tame compared with
There can be no moral justification for the death of one single person.
Imagine what OHS would look like if this principle were generalised!
Rather than balancing the trade-off between public health (death and injury rates), public costs of improved infrastructure and individual driver convenience, it is recommended that the state spend whatever it takes and reduced speed and BAC limits to whatever it takes, to achieve a fatality rate of zero.
Where did this myopic approach that spurns any kind of cost benefit analysis originate? Sweden. Where else?
Every state road transport authority in Australia now pays lip service to this anti-numerate principle. No cost-benefit ratios for these heroic folks. The objective is zero fatalities – period. Yet, slower cars still spew out (probably more) pollution that increases lung cancer. That’s just fine. Death from bingeing on hamburgers is just fine too. So do they insist on spending infinite resources on medical research? No. Only deaths by road trauma are valued at infinity dollars.
Surprisingly (or not depending on you view of current culture), when I have mentioned this odious principle to people at barbeques most think it is OK.
What is wrong with it? It contradicts the free choice of every one reading this article who has ever driven. When you did so, you made a discretionary and voluntary decision to risk your very life for the pure convenience of getting point to point faster. You personally decided against zero risk. It is a unanimous decision. Most of you probably maximised your risk by driving at the limit too. Yet the Zeroists would impose their alternative vision upon you, regardless of the personal or public cost.
Now if society as a whole wants to target zero that is a rational (though unachievable) option. But we should at least be aware that we have spent all their lives up to now making a completely different free choice. And this free choice is consistent with Vision 28, not Vision zero.
What is the death rate by shark per swimming hour? I always tell people swimming is much safer than driving but can’t find an estimate for swimming hours, so I could be wrong.
Think it must be much higher than death by snake bite, there are about 2 deaths per year for the whole of Oz.
A swimmer is far, far more likely either to drown or to pick up a fatal waterborne infection than be taken by a shark, though they’re not particularly newsworthy deaths.
Under Vision 28, can I sell my unused allocation to someone else? (Like the way fishing rights, polluting rights, etc, can be traded under market-based environmental mechanisms.)
Risk would thereby be allocated more efficiently — people who derive great benefit from driving can “buy” the right to travel more km, or travel faster (or travel more drunkenly!).
James, the death rate by shark is so low and variable that the rate will be close to random. http://taronga.org.au/animals-conservation/conservation-science/australian-shark-attack-file/latest-figures says 202 deaths since 1791 (223 years) so less than one per year. Total swimming hours I can’t find, but I’m going to guess 20 million (one hour each). For comparison, the Cronulla Sharks kill almost as many people every year :) (accurate to +/- 1)
Chris, I thought the road engineer types used ~$1M/life in their cost-benefit calculations? I’ve definitely seen numbers in that range used when arging for better protection for non-motorists. The “infinite” value makes no sense, in that if it was true we would observe that (for example) private cars would be banned from roads because the cost is infinite but the benefits are finite, thus the cost/benefit ratio (which mathematically is actually benefit over cost) would be zero. You’d actually only see this at lower level projects, anything with direct state or federal government involvement is determined by politics not science.
Risk management as an approach is built on a fairly deep understanding of statistics, which is another way of saying that laypeople can’t possibly understand even the most rudimentary risk assessment. The obvious consequence is that any democratic process will be largely unaffected by risk assessment.
Grog is far from the only drug consumed.
It is quite likely that in 25 years most cars will be, at least most of the time, on some sort of ‘auto pilot’.
BTW most current very serious offenders are repeat, unregistered, (or using a ‘elderly relatives license’) sometimes stolen and so on- whats the odds for them?
Paul H. You are right on the money with the trading system. The idea for this post came during a discussion of cap and trade. But since the post was already too long, I thought I would leave the issue for inevitable apt comment!
John W. I agree that cars will probably be on auto-pilot at some time this century. There might however be a 50 year period where we are electronically monitored but still in control. I am not sure you are correct about most fatalities being by unregistered repeat offenders. Any way, with electronic licenses this would not be possible.
Not sure about total numbers of fatalities, but your logic suggests that a reckless, high speed, ‘zonked on ice’ repeat offender, is much much more likely to seriously crash in a year or two , and kill/ main several people, than the median driver in a whole life time, no?
Chris, the obvious reason these campaigns are hyperbolic is because they work and have worked previously and some risks (e.g., drinking, driving like an idiot) are far easier to stop than others (e.g., driving a lot). This is good for almost all involved and is a common sense way to reduce road problems given a limited amount of money.
For example, unlike your logic, where only deaths are examined, with cars you really do need to look at other costs, which are huge.
Let’s have a look at what this means:
Let’s assume that, for each death, there are 5 serious injuries which pretty much end people’s lives as they know it. (This is a conservative estimate, see e.g., here)
With a road toll of 500, this means 2500 people now get to live the next (say) 40 years of their lives in chronic pain, dribbling on themselves, unemployed, and on a disability pension. Based on this, you will have (40 * 2500) = 100,000 of these people alive at any given time. Even ignoring the opportunity costs of people who were once productive workers, costs to the individual (e.g., chronic pain, depression..) and so on, this is a huge cost just in disability pensions alone.
Now it’s hard to estimate exactly how much the road toll and injuries have been reduced due to these campaigns versus better roads, safer cars and so on, but it is certainly not zero. Ever noticed how few people drive drunk all over the road these days? how few people don’t drive safely compared to 20 years ago? how few people don’t wear seat belts? etc. . I have.
So lets say these campaigns are responsible for about half the reduction in the road deaths since the 70s. That’s about 1000 people, or twice as many that die now. This means they’ve also stopped 200,000 people living miserable lives and getting the disability pension.
Given this, it’s hard to think of a more successful long term health campaign in Australia (apart from smoking and possibly AIDS), and I’m thankful that common sense prevailed across multiple governments in multiple states even if one can nit-pick various strategies and various wordings of documents.
Double? I think you are way off. Let’s do some back of the envelope calculations.
(1) At least a quarter of fatal road accidents involve drivers over the alcohol limit.
(2) Only 0.4% of drivers are over the limit.
If we combine (1) and (2) the ratio of fatality risk is:
0.25 / 0.004 : 0.75 / 0.996 ~= 83:1
83 times the risk, not 2. I guess you have aptly demonstrated how humans are so poor at judging risk. This means that you only have to drink drive about 4 days a year (a bit over 1% of the time) to double the risk you pose as a driver overall. I don’t think I have a problem with socially or legally sanctioning such unnecessary risks.
Desipis: Not correct. The risk at 0.06 is about double that at 0. You have calculated a relative risk factor integrated over the accident involved BAC distribution. This includes a small number of people at high BAC’s where the factors is in the 1000’s. By the way: estimates of the % of drivers over the limit is almost always an under-estimate.
Conrad: “Unlike your logic, where only deaths are examined..” I mentioned in the second paragraph that you might want to include injuries! It really makes no difference at all to my argument how you measure road trauma costs.
You have spent several paragraphs describing the costs of injury and argued that speed and BAC limits have “worked” even though you admit that “it’s hard to estimate exactly how much the road toll and injuries have been reduced.” Your only argument seems to be that the limits have been more effective than no limits at all.
Since you seem then to be arguing that the campaign is justified by any reduction in injuries regardless of costs (liberty, time and convenience), it would appear then that you support Vision zero. In this case you would support blanket BAC limits of zero and speed limits of 40km/h everywhere. No? If not, you just made a trade-off. I which case you need to think more carefully about my post.
I think plenty of people are happy to think about the trade off. However, I think there’d be a lot of objection to framing such thoughts in the confines of a simplistic mathematical equation.
I think you’re reading too much into the rhetoric if you assume that anyone but the most die hard ideologues takes the zero target concept in a such a literal sense. As you point out humans are poor at dealing with risk; the rhetoric is aimed at impacting common attitudes that safety is too hard/expensive/inconvenient, not provide a framework for a rational risk management analysis.
“You have spent several paragraphs describing the costs of injury and argued that speed and BAC limits have “worked” even though you admit that “it’s hard to estimate exactly how much the road toll and injuries have been reduced.” Your only argument seems to be that the limits have been more effective than no limits at all.”
Unfortunately the problem with real world problems is it’s actually very hard to get perfect estimates of things, especially when things co-occur. No doubt somewhere in some police document they’ve probably got some estimate of all the different things they’ve done which I’m not privvy too, but given there are any number of things that could of caused the road toll to get to less than 1/6th of what it was 40 years ago, isolating them would be quite hard (presumably excluding the campaign to get people to wear seat-belts). For example, I can’t tell you what advertising against smoking did (vs. general health awareness) or what percentage of the variance the Grim Reaper sucked up either. But I can say (a) Australia has exceptionally safe roads; (b) we have an exceptionally low smoking rate; and (c) we have an exceptionally low rate of HIV. Presumably none of these are because of random occurrence because these factors are more or less identical to other countries without such low rates (i.e., many countries have more or less the same cars as Australia and many countries have better roads too. Thus the difference in death rates must be due to other things).
In any case, given we arn’t driving 6 times less than 40 years ago, I find it very hard to see how your argument about likelihood of death and the amount you drive here being especially sound. No doubt people that drive more die more too, but this is clearly moderated by all of the other things going on. That is, even if you drive more, you are safer because there are less people doing dangerous things to hit you and because you are more or less forced to do safe things yourself.
“Since you seem then to be arguing that the campaign is justified by any reduction in injuries regardless of costs”
I’m not saying that. I’m saying that I’m more or less happy with the amount of money being spent and restrictions on driving that we have. I have also noted that the campaigns have been somewhat hyperbolic, like most successful health campaigns, but that I don’t particularly care about that given for all intents and purposed they have worked very well. As it happens, I’d be happy to see people drive 40kph in residential streets in some circumstances, as already happens around schools in many places.
Out of curiosity, and given your complaints about myopic policy, I just looked up Sweden. You are complaining about the country with the lowest fatality rate of any country on kilometers travelled where the data is available (here). What terrible ideals they must have, what with a BAC safety level of 0.02.
If Australia was able to get to the Swedish rate of deaths per 100K (3.0 vs 6.1) , this would save about (250 difference-in-deaths * 5 serious injury rate * 40 years) 50,000 from living with serious injuries.
Any figures as to numbers of drink driving convictions over the past decade? And as to how many are mid to high range, then and now?
And the same for higher end speeding convictions?
Conrad: Thanks for linking to the same site I linked to in the post.
“No doubt people that drive more die more too, but this is clearly moderated by all of the other things going on.” Not at the individual/year level it is not. If Chris Lloyd drives twice as many kms in 2014 his risk will be (roughly) doubled.
As an academic (and responsible citizen) I care a hell of a lot about hyperbole. Public campaigns that are full of bullshit can easily get out of hand. Think “toxic tax based on a lie.” Think “irrefutable evidence of weapons of mass destruction.” It really is just crap to demonise those who drink and speed at lower levels. Does it matter? Yes. The immediate cost is that it diverts attention from the much more important but difficult to measure variable – driving like a complete dick head – whic is largely completely unsanctioned.
My opinion on Sweden (since you ask) is that they have a compliant emasculated population who are incredibly risk averse. If they are really making a conscious free national decision to accept severe penalties for drinking/speeding in exchange for a few hundred less deaths then that is their decision.
“What terrible ideals they must have.” Where is your silly sarcasm is coming from. I have explicitly said otherwise in the last paragraph (again, did you actually read the post?).
Again, by focussing on the death outcome above all considerations, by implying that I am somehow morally lacking by arguing that it is a personal/national judgement call, you are implicitly valuing every human life at infinity. That is your prerogative. It is not irrational so long as you follow it through. Which you do not.
Riddle me this. Why is meat not banned in Sweden? It would save many more lives. Answer: Because people like the taste and are prepared to die earlier for the privilege. But you know better.
Do you really not see that a rational policy is not one that minimises deaths? Just stop now mate. You’re embarrassing yourself.
Desipis:
“I think you’re reading too much into the rhetoric if you assume that anyone but the most die hard ideologues takes the zero target concept in a such a literal sense. ”
If only it were so. Look at the quotes I gave in the post. They are not ambiguous and they are unchallenged within road management authorities and there are plenty of die-hard ideologues around.
The full Vision Zero implementation is only presently limited by the unpopularity of following them through.
So we will be executed slowly. Have you wondered why it is increasingly difficult to turn right in Australian cities? Red arrows everywhere. This takes human error (i.e. judgement) out of the equation. Just wait at the light mate, because we don’t trust you. Justification? It saves lives! And I am sure it saves a few. So what.
“Public campaigns that are full of bullshit can easily get out of hand”
Alternatively, they can do great good as well. I don’t how much money (and misery) the completely over the top campaigns on smoking, HIV, skin cancer, and so on save, but it’s a lot.
“The immediate cost is that it diverts attention from the much more important but difficult to measure variable – driving like a complete dick head – whic is largely completely unsanctioned.”
These factors are more or less orthogonal. I don’t see why you wouldn’t go after them all (which is what the government does).
“My opinion on Sweden (since you ask) is that they have a compliant emasculated population who are incredibly risk averse. ”
I don’t know if this is true or not, but if it is surely, you would surely want tougher laws when it is not the case, not weaker ones.
“Again, by focussing on the death outcome above all considerations, by implying that I am somehow morally lacking by arguing that it is a personal/national judgement call”
I’m not focusing on death at all, nor valuing life at infinity. In fact, I did the opposite, I just used it as a convenient way to focus on the cost of seriously injured people (c.f., dead people), a large amount of which is paid for by the taxpayer through health care, rehabilitation, and pensions. As noted, even “for a few hundred less deaths then that is their decision” as you put it (or in our case, a few hundred more), the cost is enormous — a mere 250 deaths a year translates into a steady-state population of about 50,000 seriously injured people someone is going to have to pay for. It would still be expensive even if this estimate is out by a factor of 2 and people just bounce back from their serious injuries. How much does that cost per year? I wouldn’t know as it depends on what you want to cost, but any under assumptions it’s rather large (e.g., 50,000 * $15,000 for pensions alone). This is clearly different to, say, 2 people getting eaten by sharks every decade which I couldn’t care less about (except for shark persecution).
I didn’t even talk about the personal cost of serious car injuries, but if you want to find out, then just go to a hospital or a rehabilitation ward. If you think, for example, that advert with the person with serious aphasia on TV isn’t close to reality, you’re wrong. Of course, you can get that sort of aphasia from other common things (e.g., strokes etc.), but these are essentially independent. I don’t see why you wouldn’t try and focus on both if you could (and given life-be-in-it and so on appear to have been an entire failure , presumably the money is better off not spent on this).
“Why is meat not banned in Sweden? It would save many more lives. Answer: Because people like the taste and are prepared to die earlier for the privilege. But you know better. ”
No, the answer is because meat kills the eater, drink driving and excessive speed kill other people also (note the government does try and stop people eating junk — it’s called food pyramid, and doesn’t work for most people).
Even for things designed to save people’s own lives, it’s probably quite good value — road laws have the advantage that with fines and stuff, the government may well make a profit from reducing deaths and injuries.
“Do you really not see that a rational policy is not one that minimises deaths? Just stop now mate. You’re embarrassing yourself.”
I think you need to work out the real costs. Please tell me the cost of the 50,000 people seriously injured and then see who is embarassed. This has nothing to do with deaths. This is a rational way to save money amongst other things.
Here’s an estimate of the cost of deaths and injuries for you Chris:
http://www.mynrma.com.au/media/Cost_of_Road_Crashes.pdf
According to the NRMA, 2.8 billion per year in NSW alone.
My maths and data could well be out, but my reading is that the the risk of dying from shark attack and car accident are similar:
23300000 People
5 Deaths from shark attacks per annum in Australia
1,500 Deaths from driving
2.66 Hours per person per annum swimming (estimate from pooling facebook)
600 Hours per person per annum driving (google)
61978000 Total swimming hours per annum
13980000000 Total driving hours per annum
0.08 Deaths per million hours swimming due to shark attacks
0.11 Deaths per million hours driving due to driving
Or did I stuff this up?
Looks correct. But I am not sure where equating shark risk and road risk ultimately leads us. People are even more paranoid about sharks than car accidents!
We’ll it is interesting how the government responds to two different rare events, both disliked by people, similar risk profile, but vastly different commitment of resources.
Yes, it is interesting. I suspect that if we swam 200 times more so that the shark death rate was 200 times higher (but the same risk per hour), then there would be all sorts of legal sanctions on swimming. No eating at beaches: no swimming with cuts; menstrual restrictions? So I think it is the total risk that drives the policy rather than the risk per hour/kilometer.
That seems right. If everyone started hand gliding, more deaths, more regulation. As kite surfing gains popularity, calls to regulate increase. It is as if the state is concerned about the number of deaths not the risk of death. Deaths by cancer would be another example. The age adjusted death rate is going down, but we spend more, because the death rate is going up.
I still don’t understand your point Conrad. Regardless of the cost of injuries and fatalities (really pick your own figure – it makes no difference to the argument), BAC and speed limits are a crude method of mitigation and have not really been subject to cost benefit analysis. And restricted freedom is definitely a cost that is NEVER considered. Under Vision 28, the total fatality rate does not increase at all. You can decrease it at will by giving people a lower allocation than 28.
Practical? Maybe not now. Maybe not ever. This is only a blog after all. But I got the impression that you were arguing against it in principle. And you seemed to be arguing in favour of zero.
As for public hyperbole, this is a fundamental value that we cannot really agree on. I believe in the truth, regardless of the consequences. No qualifications apart from privacy and national security (maybe). The consequences of abandoning this principle are just too numerous to mention. So let me say it again with great pride. If you drink and drive you are not (necessarily) a bloody idiot.
“BAC and speed limits are a crude method of mitigation and have not really been subject to cost benefit analysis”
Chris, there’s any number of studies that show people have more accidents over about .05 (I’ve personally seen the Victorian as my department once had a PhD student from the police force looking at this sort of stuff and it looks as expected — basically a power function with a slow rise until .05 and then a curve that rises quickly). However, since things like speed, BAC, and driving like a dickhead surely interact, presumably you can really only look at the entire package of measures (some which may very well have little effect — but it’s not exactly ethical or practical for the police to staircase values until the collision rate goes up and then reduce them again). So, for example, if you assume the whole package of measures saves about 1000 people per year, then, based on the NRMA figures, that’s probably about 8-9 billion. No doubt people drink less, so the Hoteliers industry loses money, and less accidents mean less work for doctors, speech therapists and so on, so there is some economic trade-off. Speed is harder since time really does equal money, and you could certainly have more complicated rules since presumably most are set for bad conditions (e.g., rain), but no country I know of in the world has these, so that’s about how much governments think people would be able to understand them (indeed, the Victorian police are on record saying they don’t like to lots of different speeds limits as they think in confuses drivers).
“And restricted freedom is definitely a cost that is NEVER considered.”
Since we’re talking about public roads (c.f., private roads), do you mean your freedom to drink and drive, or my freedom to have safe roads and not be injured by others? Even with private roads, my freedom to not pay taxes for all the injuries etc. cars cause. Personally, I value not being seriously injured very highly and am willing to accept the current known best practice (i.e., limiting speed and BAC and tough enforcement, which you think are crude measures) to make them safer within reasonable limits, like those we have now — the roads and drivers in Victoria at least are much better than 20 years ago (perhaps excluding indicator usage). If you can suggest better measures which the public understands, I’d be happy to have them.
“I believe in the truth, regardless of the consequences. ”
Most of the hyperbole is truthful — some is misleading but not untruthful. For example, in my opinion, the smoking campaign is probably reasonable and not even misleading. Health consequences really are bad with smoking. Alternatively, whilst not dishonest, the drugs campaign is misleading. The main consequences of pot, for example, are sure to be more or less the same as tobacco and not schizophrenia, and the main consequence of ecstasy is certainly brain damage and not death. Even with alcohol, the biggest costs are probably long term health problems for heavy drinkers, not violence.
I actually published a study in the Journal of the Royal statistical Society (back in 91) where I estimated the relationship pretty accurately: based on comparing random tests (by a research term, not the cops) with all fatalities. It is probably the best data available, even now. The risk does go up more or less exponentially, it goes up more quickly for under 21 year olds and quite slowly for 51+ drivers. I guess people learn how to drive pissed correcting for their state of inebriation. Or it could be an interaction with speed as older people drive more slowly.
Regarding tailored speed limits you note “no country I know of in the world has these”. Not quite right: they have different limits in snow conditions in some countries. And there are lower speed limits for learner drivers. But I take your point that my overall idea had not been implemented anywhere. But this is a completely speculative blog! And thought experiment – how would we manage this problem in an ideal technological world – are useful I think. And I think the main conclusion that comes from my cogitation is that Vision Zero is a terrible idea.
You say “I value not being seriously injured very highly”. Fine. So do I. But that is a very rare event, and restrictions on my speed and BAC are a daily event. My point is that some people value their freedom and the cost of restriction very highly is never mentioned – ever – either in mass media or research documents. Rather, the usual argument is circular: “if you don’t like being fined then don’t speed.” There are more and more public safety restrictions imposed on us in this way. Think OHS at the University where my office is inspected for wrinkled carpet and heavy books on high shelves.
I agree with your last paragraph. Smoking campaigns are pretty truthful. The danger of illicit drugs is probably exaggerated. But I think the hyperbole on drink driving is the most misleading of all.
P.S. Sorry for the terse comments on Tuesday. I had a really bad day.
Interesting post Chris. Slight tangent, but it’s worth asking whether a better metric than deaths/injuries per km might be deaths/injuries per trip. This avoids biasing the statistics in favour of long distance travel. Arises a lot in comparisons between air and land based travel and also between long haul and short haul aviation (if the metric is based on passenger kms then long haul flights are always safest). Depends whether you think the purpose of travel is to get from A to B – in which case, the per trip metric is better because it is irrelevant how far B is from A – or whether it is to cover a lot of distance.
If Vision Zero holds nearly as much sway as you think Chris, there can be little doubt that human driving will be illegal within a pretty short period of time. The 50 years of “interim period” bandied about above will be more like 15 at most.
“But that is a very rare event, and restrictions on my speed and BAC are a daily event”
Sure, but speed restrictions and BAC have approximately zero effect on my life, but brain damage or even something more common like chronic back pain would pretty much end life as I know it. This trade-off is hard to evaluate, but you could just go through the numbers, and ignore social costs (and secondary costs which never get added in these things, like, for example, the cost of people who get divorced/suicide due to chronic pain issues), psychological trade-offs between common small annoyances vs. deathly big ones etc. and then see where you get.
Let’s just assume that the extra 1000 people you are happy to sacrifice for convenience really does cost 8 billion.
This means 20 million people get more convenience. So to pay the costs of the accidents you need $400 per person (8 billion/20 million). Since only about half the population is likely to pay for this (the rest who don’t pay tax will freeload), this means $800 per tax payer. Assuming the non-free loaders earn $40 p.h., this means you would want to save about 20 hours per year for the extra convenience just to pay for the cost of the accidents.
How much do you have to drive to save 20 hours or who is going to save the time?
If you drive 300 days a year, this means you need to save 4 minutes each day. This doesn’t sound like a lot, but even if there were no speed limits in Melbourne, it’s not clear to me I could do that (let alone Sydney). The only time I can actually get over the speed limit for any meaningful number of kilometers is when I’m not going to work. So this limits the number of days I can actually try and meaningfully recoup this cost — perhaps to 20 for me. Even driving reasonable distances (e.g., to Phillip Island) on these 20 days, I couldn’t hope save 1 hour each time. I can of course start trying to accelerate really fast between lights when I go shopping etc. but I doubt I’ll get too much back like that, and if we all start doing this, then your 1000 deaths is probably going to be conservative.
So this means to pay for the extra accidents, a small number of people will need to accrue most of the time benefit. The most likely group would be trucks travelling long distances, but even those guys may not accrue such a benefit since I’m led to believe that fuel costs more the faster you go after a certain speed — It would be interesting to know what speed trucks would go if there were no limits apart from on short downhill sections.
Perhaps I’m way off here, but even if this is somewhat correct, at least for road safety, I’d really need further convincing evidence before deciding that just the trade-off was a good idea.
I should say here that I’d be happy to see real analysis of these things, and I also think it’s contextually specific. So road safety, for example, is entirely different to the crazy regulations OHS people do in places like universities — it’s hard to see how I’d injure myself even if a heavy book dropped on my head.
Here is an alternative and simpler calculation for compliance costs. How much would you be willing to pay personally to be completely free of BAC and speed restrictions for one year?
Imagine I offer you a deal that you can drive at whatever speed you like and at whatever BAC you like. How much would you pay? Personally I would pay around $2000, mainly for the speed limits which I think are ridiculously low much of the time. I would pay extra for the right to turn right against a red arrow (which I do pretty often anyway). But it is personal. If you do not drink at all and already drive below the limit you will pay zero.
Let’s take $1000 as an average. If there are 10 million drivers this is $10 billion per year. The 1000 lives cost $8 billion. I actually think the $8 billion is pretty ridiculous. It values each injury/death at a NPV of $8 million. But you might disagree with my $1000 payment to avoid limits. What is clear though is that these amounts – compliance versus injury – are a similar order of magnitude. So the issue of trade-off is a live one.
The 8 billion is the cost of all accidents, not deaths. I just used the deaths as a convenience under the assumption that the ratios of deaths/accidents would stay more or less the same. I didn’t see it as too bad given this, which is not to say you couldn’t come up with different numbers depending on what you want to include (i.e., long term social costs).
I personally wouldn’t pay anything for it, since I don’t drink much (and just use taxis if I do), and most of my driving isn’t constrained by possible speed limits, although I agree many speed limits are stupidly low, like on freeways — I guess the question then for a government that spends 1 billion on Myki is “do you want to spend billions upon billions for an electronic speed limiting system that changes depending on the conditions”. Personally, I’ll wait until they’ve fixed more simple things, like fly-overs for train tracks, before worrying about something like that.
Back to the point though, if you want a scenario like you suggest, what you are really doing is buying rights to injure random others. If this is the case, and you are talking about “freedom”, it can alternatively be conceptualized as the potential victim setting the price. “How much would you accept to increase your probability of accidents”. This of course happens all the time (e.g., pollution, drug testing), and it’s already assumed with BAC of .05. You might want to pay $2000 but someone else might want $4000 for it — it just depends on how much they value different things (and based on people’s preference of disliking losses more than they like gains, it’s likely to be more than the economic cost).
An alternative question would thus be to ask something like: “would you accept $1000 for tripling the risk of having an accident”. I doubt too many people would choose that but it’s obviously an empirical question. People participate in drug trials after all.
Glad to see that I am not the only one with unorthodox ideas on road safety. Have a look at this. Seems rather sensible on first inspection. And yes, I know that he believes in guns and charging asylums seekers too….
Just in case anyone thought I was exaggerating about Vision zero though, in the same article
So the department is utterly failing then.They should all resign in disgrace.
I like the idea of faster speeds on major freeways since they are one of the places you can get reasonable data about accident rates, even out of peak hour lots of people take them so you could get reasonable cumulative time-savings, and some of them already have electronic speed signs so you could presumably change the maximum speed depending on the weather and time of day.