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Guest Column

29 January 2002

By Tom Harley

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I would like to congratulate Dennis Jensen and AutoSpeed for the article "Speed Kills - The Big Lie?". This was a very interesting article that challenged a number of commonly held beliefs by exposing the popular statistics used by regulating authorities to be flawed. I do have a few comments on the article, however.

Firstly, I agree that the statistics used by regulating authorities are interpreted (some might say 'manipulated') to serve their cause. As they say, "lies, damned lies, and statistics". For example, it is clear to any thinking person that by increasing your speed by 10 km/h you are not doubling your braking distance, unless you are talking about a change in speed from about 25 km/h to 35 km/h. Above this, the increase in braking distance is significantly less.

I also question the use of speed cameras, particularly in metropolitan Perth, where I live. I was once a believer that speed cameras were used to free up police to do "real work" and that they, overall, truly kept the speeds down. Today, I am not so sure. Despite the publicity of the 'in-depth analysis' used by the speed camera committee in Perth, I question whether they could justify the placement of speed cameras in many Perth locations based on their claimed criteria. We frequently find speed cameras on dual-divided carriageways, which are arguably some of our safest roads.

Two perfect examples contradicting their claimed policy are at the entrance and exit of the Northbridge tunnel. I fail to see how a dual, divided carriageway that has no intersecting roads can be in the 'high-risk' or 'frequent' brackets for accidents, and thus justify the use of speed cameras. With all traffic travelling in the same direction, at roughly the same speed, this must surely be one of the lowest risk roads. The other example is a similar dual, divided carriageway leading to Perth International Airport. There are approximately 3 intersecting side-streets (service roads), which carry virtually no traffic at any time of the day, and the ground is open enough to see vehicles for many hundreds of metres. The placement of cameras on this road is obviously designed to catch people running late for a plane.

Similar is the use of cameras on country roads set with city enforcement thresholds. Although I have no references to support this assertion, I feel confident in saying that the far greater majority of accidents on country roads are due to tired drivers or other factors, and not due to speed.

Further, several years ago the WA government adjusted is speeding fine brackets to accommodate a reduction in the enforcement threshold, an increase in dollar value of each infringement, and the increased use of speed cameras. One may observe that the most common speed motorists are fined for (was 14-29km/h $75, 3 points; now 11-20km/h $100, 1 point) has increased (marginally) in dollar value while, incomprehensibly, the number of demerit points has decreased. Cynics may suggest that this is prima facie evidence that the regulating authorities do not consider speeding by such an amount to be overly dangerous, or that they would prefer to allow motorists greater opportunity to contribute to the state revenue.

I wholeheartedly agree with Dennis Jensen's assertion that the phrase "speed being a causative factor" is greatly misused and even more greatly misunderstood. Once again, interpretation is the key here - and the agenda of those interpreting. I worked for some time as a uniformed police officer and I can confidently say that very few of the many hundreds of accidents I attended or took reports for were caused by speed. One may assert that speed contributed in some way to some accidents, but then so did the road surface, time of day, mechanical state of the vehicle and its components (such as tyres) and a multitude of other factors.

Most frequently, this assertion regarding speed is confused with a lack of skill on the part of the driver. My observations are that most accidents would be avoidable if the skill level in drivers were higher. In reality most accidents are caused by inattention on the part of a driver - but it is their lack of skill that often makes the accident unavoidable. This is where supporters of an increase in driver training chime in and suggest that the answer to decreased accidents is increasing the average skill level by further driver training. Unfortunately, increasing the skill level of drivers by an appreciable amount is not as easy as completing a one-day "defensive driving" course, and - as I have seen time and time again - there are simply some (many?) people to whom you cannot impart these skills to - and any further training has rapidly diminishing returns.

Some people just have no road/car sense or an awareness/understanding of what is going on around them, and even more have an inflated notion of their ability as a driver - which, in my opinion, is infinitely more dangerous.

The other great cause of accidents, which may be viewed as a sub-set of overall skill, is poor judgement on the part of the driver. Accidents in this category are caused frequently by a driver exercising bad judgement in relation to, for example, the speed of an oncoming vehicle, the performance ability of their own vehicle (traction, braking, acceleration etc) and very often their ability as a driver in reacting to and handling an abnormal situation.

Both "causes" I have suggested would appear, on the surface, to be helped by an increase in driver training. While this would be true to a certain degree, what I believe these training courses frequently do is increase the confidence level more than the skill level, particularly in younger drivers. This is a very dangerous imbalance. There is only so much that can be done in a one or two day course.

For most of the time that I am driving I pay little regard to my speedometer. Thanks to my radar detector, I can spend most of my time looking out the windows at the other vehicles on the road, driving at a speed I believe is appropriate to the conditions. Sometimes this will be above, sometimes below the posted speed limit. I know that it is infinitely safer for me to spend my time looking at my surroundings rather than glancing at my speedo every five or ten seconds to ensure I'm maintaining the speed limit.

Hypothetical: I'm travelling down a road and a vehicle pulls out, very close, in front of me. This scenario will have one of two outcomes:

1) I am unable to avoid the accident and collide with the other vehicle.

2) I take the appropriate action and am able to avoid the accident.

In the event I am unable to avoid the accident, how much blame should be apportioned to me if I am travelling in excess of the speed limit? How much blame should be apportioned as my speed in excess of this limit increases: 0 km/h over, 10 km/h over, 20 km/h over, 40 km/h over? Some could rightly argue that if I was travelling slower I would have been able to avoid the accident. The obvious counter to this is that if the other vehicle did not pull out, there would have been no risk of accident in the first instance.

Unfortunately there will always be a person, due to inattention and/or poor judgement, who will pull out into the danger-zone regardless of whether you are travelling at, above or below the speed limit or 85th percentile. So an across-the-board increase in driver skill should reduce this problem, right? If increased driver training actually increased long term skills by measurable amounts I would say 'yes'; however I do not believe that the increase in skill required is able to be achieved within cost and time constraints associated with driver-training courses (yes I realise this is very debatable).

Over the years, I have undergone a considerable amount of police driver training and was able to practice and consolidate that training on virtually a daily basis. To equivalently train the average citizen would, by my estimation, take approximately eight weeks of full-time intensive training and cost somewhere in the region of $30,000. Clearly, even a fraction of this money and time is not feasible for the average driver. Then, of course, there is the ongoing need to review and refresh those skills...

So if we consider that driver training is not a viable option, what are regulating authorities left with? How can the accident rate be most efficiently (result per dollar) reduced? The obvious answer is to reduce the speed at which the vehicles travel. By doing so you increase the safety margin for drivers in most cases with regard to reaction time, overall energy, and controllability of the vehicle. And if it should happen that vehicles do collide, they should have less energy on impact, which, very generally, should result in a lower incidence of injuries.

So what is the bottom line? Does slowing down save lives? If you believe the government's statistics, you'd say yes. If you believe the 85th percentile statistics you'd say no. I believe that reality is too complicated to fit neatly into either statistical paradigm. The "85th percentile" statistics are certainly not flawless and there are some very solid criticisms of their validity (eg reduced accidents due to 85% of traffic travelling at the same speed, not necessarily a higher speed; type of roads; type of accidents), but I believe the over-simplified stats used by the authorities are often worse.

If I reduce my speed from 60 km/h to 50 km/h in a local street, a child may still run out in front of me causing an unavoidable accident. If I increase my speed to the 85th percentile speed, say 65 km/h, the same child could do exactly the same thing. For a given scenario, however, I'll have more chance at avoiding the accident if I'm travelling at the lower speed (the actual incidence of neighbourhood pedestrian accidents is another matter altogether, however).

It is frequently cited by supporters of 85th percentile limits that accident rates aren't significantly affected by an overall change in speed (though there are a number of contradicting studies). I would suggest that the statistical support of this assertion could be explained by the fact that, as I have asserted above, most accidents are due to inattention. However, what all of these statistics don't take into account is the number of accidents avoided (as they will never be known) due to a vehicle travelling at a slower speed.

Safety on our roads is about people driving to the changing conditions around them, not a fixed speed. Unfortunately the majority of people are not responsible enough or do not have the ability to suitably judge what is required by the conditions around them - therefore the only viable response available to the authorities is to reduce allowable speeds whereby a happy medium of safety and traffic flow are reached - in effect, applying laws based on the (lowest) common skill level.

I resent being forced to drive at a significantly slower speed due to the poor skills of other drivers, but before I turn my key and take to the road, I know what the rules are. If I choose to exceed the speed limit, I know I risk the penalty of the day. I may disagree with speed limits in certain areas, or with the method of enforcing those speeds, but I am always aware of where the goal posts are. When I choose my speed, I choose my consequences.

NB: As if to both prove and disprove some of my assertions, I finished writing this, left the house, and had an accident. I had been doing approximately 20 km/h under the limit, allowing me to brake and manoeuvre such that the impact and damage were minimal. Had I been doing the speed limit or above the damage would have been much worse with a real potential for injury. Cause of accident: 100% inattention on the part of the driver, who did not even know I was there until we had collided. Hard way to prove a point eh?

Footnote: At the request of the author, a pen name has been used in the credit for this Guest Column.

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