Over the last few weeks Mark Temby has written several opinion pieces in the Tasmanian Times under the title ‘Road Safety: Inaction by our local and state politicians and relevant authorities’ ( HERE ).
As the title suggests, these articles hit out at what Mr Temby perceives as either wrong-headed or inadequate government action to address road safety issues. Along with more and faster work to improve roads, his principle road safety policy prescription is for lower speed limits on many roads, especially an 80 km/h limit on the rural sections of the Channel Highway.
In this piece I will argue that the focus on speed reduction and enforcement in jurisdictions across Australia is already past the point of diminishing safety returns, and is deflecting attention from a much more important issue; driver inattention. Moreover, speed limits set too low combined with zealous enforcement of very minor infractions turns safe and responsible driving into an offence, which unfairly tarnishes the reputation of the police; unless there is compelling evidence that such policies actually reduce the road toll they should have no place in a country that values individual freedom and responsibility.
Lastly, I will argue that the ultimate determinant of road safety is not government regulation and initiatives, important as they may be, but rather depends on individual road users paying attention to what they are doing and taking responsibility for their own safety and that of others.
Firstly, there is no question that increased speed makes the consequences of any crash much worse. This is because increased speed increases the kinetic energy unleashed in a crash by the square of that increase in speed, and thus increases the consequences of a crash significantly. For example a crash at 110 km/h rather than 100 km/h involves 10 per cent more speed but 21 per cent more energy. Thus it is entirely predictable that, as Mr Temby notes, ‘in the past five years, 41 per cent of road fatalities and injuries have occurred in 100km/h zones (typically rural roads) being a higher proportion than any other speed zone’; speeds on these roads are higher than on urban roads so crash consequences are worse.
This does not mean that speed caused these crashes, yet Mr Temby nevertheless claims that ‘excessive speed on rural roads is recognized as the primary cause of most road fatalities’. This is both wrong and disingenuous, conflating the consequences of crashes with their causes. In fact DIER’s statistics from the current Road Safety Strategy1 tell us that 83 per cent of fatal or serious casualty crashes on our rural roads involve single vehicles (65 per cent) or head-on collisions (18 per cent), of which perhaps 12 per cent were related to inappropriate speed. Something other than speed is at work here; I suggest the root cause is driver inattention, of which more later.
Furthermore, as Mr Temby notes, the 2013 Legislative Council Select Committee on Rural Road Speed Limit Reductions found that ‘the majority of serious and fatal crashes on non-urban roads are attributable to a variety of causes in which speed is not a factor. This is supported by analysis completed by the RACT and by statistical information provided by Tasmania Police’.
Nevertheless, across Australia, governments focus heavily on speed and speed enforcement. The current DIER road safety strategy states that ‘speeds just 5 km/h above the speed limit in urban areas and 10 km/h in rural areas are sufficient to double the risk of a casualty crash occurring’. This finding is not disputed, but the wording is crucial. It does not say that the risk of a crash doubles with each 5 km/h above the speed limit, but that, in the event of a crash, the risk of there being a serious casualty doubles.
These kind of statistics are generated from the Power Model2, which governments use to estimate the safety benefits likely to result from a reduction in speeds. The model provides a mathematical correlation between increased or reduced average travel speeds and the probable severity of an accident. Using this model:
• Serious casualty accidents are represented by the third power, so a reduction from 100 to 90 km/h should reduce casualties by 1-(0.9)3 = 27 percent.
• Likewise, a reduction from 100 to 60 km/h should reduce casualties by accidents by 1-(0.6)3 = 78 percent.
The Power Model and statistical analysis of the relationship between speed and serious casualties are certainly useful, but have little to say about the causes of accidents and offer no help in deciding speed limits. The model will always tell you that the speed limit should be lower. If you propose a reduction of the speed limit from 100 to 90 km/h on the basis that it will reduce serious casualties by 27 per cent, why would you not pursue a reduction to 60 km/h, because that should reduce serious casualties by 78 per cent?
We are also regularly told that increased speed increases the likelihood of a crash, although the evidence for this is nowhere near as compelling and the effect is dependent on circumstances. I doubt there is any measureable increase in crash likelihood (as opposed to crash consequence) as speeds increase on good roads, especially freeways. On the other hand, increased crash likelihood is entirely credible on winding or wet roads where quite small increases in speed can rapidly and unexpectedly take a driver beyond the limit of traction and cause a slide leading to a crash; as with the kinetic energy unleashed in a crash, g-forces increase with the square of the velocity.
Note at this point that the relationship between speed and both the consequences and likelihood of crashes is independent of speed limits; on any road short of a freeway there will be sections of road where it is not possible to travel safely at the speed limit and drivers must exercise judgement to drive to the conditions; in the wet or winding road example above there will be many places where a dangerous speed is well below the actual speed limit.
Once speed limits and speed enforcement are conflated with issues of crash likelihood and consequence the argument becomes less credible.
Speed Limits and Speed Enforcement
Against this background, let’s have a look at the arguments for reduced speed limits, and specifically the proposal for an 80 km/h limit on the rural sections of the Channel Highway. There is some history here, involving the previous government’s proposal to reduce the default Tasmanian rural road limit to 90 km/h, and the associated Kingborough and Tasman ‘Safer Speed Demonstrations’.
The first point to make about these demonstrations is that the trial reduction of the limit from 100 to 90 km/h did not result in an improvement in road safety. This was to be expected because, as predicted by the Power Model, reductions in casualties are dependent on reductions in actual, average travel speeds, not on the speed limit, and average travel speeds barely changed. A further reduction to 80 km/h is also likely to make little difference to average travel speeds so is unlikely to reduce the road toll. However, as with the existing 90 km/h limit in Kingborough, it would unnecessarily prevent people from travelling at higher speeds on those sections of the highway where conditions safely allow.
In other words, the Safer Speed Demonstrations provide empirical evidence that reduced speed limits on these kinds of rural highways will not improve road safety. They do not support the case for imposing lower speed limits.
In the event there was strong opposition to the proposed reduction of the rural limit to 90 km/h and the then government rejected the proposal, putting a sensible focus on ‘driving to the conditions’ within the existing 100km/h rural road limit. As Mr Temby notes, the new government has retained this position. Minister Hidding noted ‘In September 2012, the Tasmanian Government launched the Non-Urban Road Network Strategy that considered the safety benefits associated with reducing the speed limit on most rural roads from 100 km/h to 90 km/h. The subject was widely discussed in the community and it was apparent that there was little mainstream support for a wholesale reduction in rural speed limits. On this basis, there is no mandate for a widespread reduction of speed limits in the Huon/Kingborough region.’
Of course there are some people who disagree with this assessment, but the fact that both major parties have come to the same conclusion suggests that it does indeed reflect majority public opinion.
In arguing for reduced limits, Mr Temby also cites a number of examples of road safety stories from taken from press reports. These stories always fall into two categories, neither of which supports the case for lower speed limits.
First are the stories about road users who were drunk, unlicenced, driving at extreme speeds, or otherwise behaving in a highly irresponsible and unsafe manner. Such people deserve to face the full force of the law as they put themselves and everyone around them at risk. However, I suggest that these stories have no relevance to the question of speed limits; for drivers wilfully flouting the law, it makes no difference what the limit is.
The second category of reports involves single vehicle accidents or head on collisions, where speed is not usually an issue, and the reason for the crash is largely unexplained. Once again such reports have no relevance to the question of setting speed limits.
I have never seen a media report where a minor infraction of the speed limit is cited as the cause of a fatal or serious casualty crash.
An important point is that speed limits are arbitrary, varying dramatically within Australia and across the world. For example:
• Around the world, freeway limits vary from derestricted down through 130-140 in much of Europe, 70mph (114km/h) in Britain, 55-75mph in the USA, to 110 in Australia to 100 or less in some places.
• In Australia, non-dual carriage highways vary from 130 (with a derestricted trial section) in the Northern Territory down through 110 on the Midland Highway here in Tasmania, with most highways around the country posted at 100. Here in Tasmania some such roads are now set at 90 and there are quite long sections of Victoria’s Midland Highway set at 80 (which is what Mr Temby proposes for the Channel Highway). In almost all cases the sections of road with lower limits are no better or worse than the adjacent 100 areas.
Thus what would be regarded as high level speeding (more than 15km/h over) on one section of road can be legal on another equivalent section. To give a local example, 95km/h on the Channel Highway in Kingborough is speeding, yet it is legal the instant you cross into Huon Valley. In neither example have the safety implications changed at all.
The credibility of the anti-speeding message is further undermined when combined with low tolerance enforcement policy. The reality of speed enforcement is that it overwhelmingly catches people who are low-level speeding, often on good roads where the speed limit is set quite low. In Victoria 80 per cent of speed camera fines are for less than 10 km/h over the limit. Here in Tasmania Assistant Police Commissioner Glenn Frame tells us that 64 per cent of fines are issued to people doing less than 15 km/h over the limit.
Kingborough has the dubious distinction of having the highest number of speeding fines across the state. I wager most come from places like the Channel Highway just south of Margate where, against DIER advice, the limit has been reduced from 80 to 60 km/h and the police regularly trap vehicles rolling down the hill at speeds well under the previous limit. Another example is the Kingston Bypass, an excellent new road with a rather low 80 km/h limit where drivers are regularly speed trapped, usually rolling downhill towards Hobart. Most drivers so fined will have been doing less than 90 km/h, a speed they can quite legally do on the Channel Highway, a far inferior road, just a couple of kilometres further south. There are many similar examples around the state. This kind of enforcement does little or nothing to enhance road safety.
This is not to argue for people breaking the law, but it does suggest that the constant refrain about the dangers of even a few km/h over the limit is exaggerated and misleading in many circumstances. This helps explain why such a large proportion of the Tasmanian community believe low level speeding is ‘acceptable’3. The message would be much more credible if enforcement was clearly aimed at excessive speed rather than people who are driving in a safe and responsible manner but have unwittingly picked up a few extra km/h rolling down a hill.
Moreover, the Road Safety Advisory Council graph of serious road casualty numbers against road safety initiatives4 shows those numbers flat-lining over the last few years, despite a heavy and continuous focus on speed. This suggests that the focus on speed is past the point of diminishing safety returns. We need to do something new to further reduce casualties. There are much more important initiatives to be pursued to promote improved driver behaviour and safety, which brings me to the role of inattention.
There is more than enough direct and indirect evidence to suggest that driver inattention is a crucial factor, often the most important factor, in almost all crashes. Direct evidence comes from naturalistic driving studies such as that by Virginia Tech5, which found that nearly 80 per cent of all crashes (93 per cent for rear-end crashes) involved driver inattention within 3 seconds of the incident.
Indirect evidence comes from our own DIER statistics which tell us that 83 per cent of fatal or serious casualty crashes on our rural roads involve single vehicles (65 per cent) or head-on collisions (18 per cent), of which perhaps 12 per cent were related to inappropriate speed. It also comes from the sad, ongoing litany of road crash and incident reports in the newspapers which I have already discussed. In many of these cases inattention seems to provide the only plausible explanation; one or two seconds (you travel 56 metres in two seconds at 100km/h) of inattention is all it takes to run off the road or cross the centre line and cause a crash. That same one or two seconds inattention also causes a much greater increase in potential stopping distances than a few km/h of additional speed, because it delays the point where braking starts by many metres.
At this point it is important to mention the recently quoted Road Safety Advisory Council statistics indicating that inattentiveness was a factor in (only) 9 per cent of fatalities and 12 per cent of serious injuries. This is highly misleading as, since 2011, inattention is only reported when it is considered to be the sole crash factor. Moreover, while speed is easy to measure or to calculate through crash reconstruction, inattentiveness is much harder to determine, at least if mobile phone records do not provide an obvious answer. As a result one would expect the statistics to very substantially under-represent the danger of inattention compared to speed. The fact that inattention is hard to measure does not mean it is not a crucial issue, nor that we cannot do something about it.
Any initiative to reduce the road toll needs to address this issue, yet it is under-emphasised. In the section on behaviours contributing to serious road casualties, the current DIER Strategy places speed first and inattention last, despite the fact that it states that inattention caused 60 more serious casualties than speed (623 v 563) in the period 1996 to 2005. That said, 623 casualties is still only 13 percent of the total of 4749 serious casualties in the period. Yet, on the basis of the Virginia study, it is not unreasonable to assume that as many as 80 percent of these accidents involved inattention, in which case it contributed to about 3800 of the 4749 serious casualties.
If that figure is even close to correct, it suggests that the danger of inattention is overwhelmingly the most important road safety message of all. If driver education and other measures reduced the incidence of inattention by even one third, that could be expected to reduce serious casualties over the next ten years by more than 1200. That is more than twice the total number attributed to speed (563) over the ten years from 1996 to 2005.
The lack of emphasis inattention is still given in so many road safety campaigns, always ranking far behind speed, alcohol, drugs and fatigue, is a dangerous omission. Unless drivers can be made to understand the absolute need to give driving their continuous and undivided attention the crash rate will not drop and the tragic death toll will continue.
It really doesn’t matter what causes the inattention, be it texting, using mobile phones, arguing with children in the back, looking at a view rather than the road or giving in to any of the hundreds of other possible distractions. It is the resulting inattention that is so dangerous.
If you are paying close attention to your driving and the situation around you, every single time out on the roads you will see other drivers, riders and pedestrians who are not focussed on their surroundings and are wandering around on the road or otherwise behaving erratically as a result. I suggest the difference between these incidents and a fatal crash is simply a matter of luck; it is tragic and harsh, but the evidence suggests that most of those who die or are seriously injured on the roads are those who were not paying attention when their luck ran out.
There is a clear message here that needs to be constantly reinforced to stop drivers becoming complacent and starting to believe that crashes can’t happen to them. The key points include:
• Driving is one of the most potentially dangerous things we do. As a driver, you are responsible for your own safety and that of your passengers and all those around you.
• To meet this responsibility you must drive safely to the conditions. To do this you must have excellent and continuous situational awareness of the road, weather, visibility and traffic (vehicles/bikes/pedestrians/animals) conditions.
• This can only be achieved by paying continuous, undivided attention to your surroundings, particularly what is happening ahead of your vehicle.
• Anything that distracts you from the direct task of driving is potentially fatal to you or others. If you fail to pay attention you are failing your most important responsibility as a driver and are playing Russian roulette with your own life and that of everyone around you.
• Nothing the authorities can do reduces the responsibility of individual users for road safety. Whatever initiatives are in place to improve the safety of roads, road laws and vehicles, they will come to naught if road users fail to meet their responsibilities.
A message like this would surely be a statement of the obvious to a parent teaching their teenager to drive. This might be one reason why learner drivers actually have a very low accident rate – teacher and driver tend to be completely focused on the task at hand. Yet once the licence has been issued, and as we get more experienced and driving becomes more routine, complacency seems to set in for many. A capable, educated man like Mr Bill Shorten (Labor Opposition Leader) is nevertheless sufficiently complacent to text while driving. We only read about that because of his high profile, yet he was only doing what a multitude of other road users do every day.
Driver responsibility and the need for drivers to pay continuous attention cannot be directed and enforced by government in the way that other initiatives to improve road laws, the roads and vehicles are directed and managed. The responsibility to drive to the conditions rests with the individual road user, not the government. All other initiatives to improve roads and vehicles, however important, are subordinate to that fact.
It should be government policy to recognise that ultimately it is the driver, rider or pedestrian that determines whether they and others are safe or not, and to continuously emphasise this safety message to all road users, both in the new Road Safety Strategy for 2017 and in future road safety campaigns.
Speed Limits and Speed Enforcement
• Stop pursuing general speed limit reductions that turn safe and responsible driving into an offence. Where there are strong reasons to do so, review speed limits on specific sections of road.
• Separate the issues of crash likelihood and consequences from speed limits and speed enforcement. Reinforce the message that quite small increases in speed can easily mean you are driving beyond rather than to the conditions.
• Focus enforcement on genuinely excessive speed and other forms of aggressive and dangerous driving.
• Unless there is clearly irresponsible or unsafe driving involved, issue warnings for low level speeding offences.
• When a particular location is yielding many low-level speeding infringements, review the speed limit. It is very likely it is set too low for the conditions.
• In the new Road Safety Strategy due in 2017 and in future road safety campaigns the following message should be clearly stated as the first priority of road safety.
o Driving is one of the most potentially dangerous things we do. As a driver, you are responsible for your own safety and that of your passengers and all those around you.
o To meet this responsibility you must drive safely to the conditions. To do this you must have excellent and continuous situational awareness of the road, weather, visibility and traffic (vehicles/bikes/pedestrians/animals) conditions.
o This can only be achieved by paying continuous, undivided attention to your surroundings, particularly what is happening ahead of your vehicle.
o Anything that distracts you from the direct task of driving is potentially fatal to you or others. If you fail to pay attention you are failing your most important responsibility as a driver and are playing Russian Roulette with your own life and that of everyone around you.
o Nothing the authorities can do reduces the responsibility of individual users for road safety. Whatever initiatives are in place to improve the safety of roads, road laws and vehicles, they will come to naught if road users fail to meet their responsibilities.
1. Non-Urban Road Network Strategy, September 2012, DIER, Tasmanian Government
2. Nilsson, G. (2004A). Traffic safety dimensions and the Power Model to describe
the effect of speed on safety. Bulletin 221. Lund Institute of Technology,
Department of Technology and Society, Traffic Enginering, Lund
3. See RSAC website ‘Speeding Shatters Lives’ http://www.rsac.tas.gov.au/campaigns/speedingshatters/
5. 100-Car Naturalistic Driving Study, Virginia Tech Transportation Institute (VTTI), 10 June 2005 http://www.vtnews.vt.edu/articles/2005/06/2005-834.html
*Peter Leschen retired from the RAN in 2010 after a 36 year career in the Permanent Naval Forces, and is now a Commodore in the Naval Reserve and a consultant to Defence Industry. He is a motoring enthusiast who has done a significant amount of both theoretical and practical advanced driver training, and has a keen interest in road safety. Among other things, he has taught his two daughters to drive, and is passionately concerned that they remain safe on our roads.