Roadcraft. In fact, Roadcraft Driver Education, Gympie. Yesterday, at the behest of the principal of EasyAs Driver Training Australia Pty Ltd, which I provide driver training services on behalf of, I attended a day long course in awareness, perception, understanding of the human condition and physiological training in vision acuity. Sounds really deep and meaningful, doesn’t it? It was, trust me. If, by now you have the roadcraft website up in another tab, you’ll have formed the impression that I had of a place where you get to hoon around on a skid pan and drive slalom style between witches hats. Well, yes, we did the latter, but not the former. What we did do was gather a far greater understanding of how physics functions in our 3 dimensional world, and how to come to terms with just what it does when we mere human beings interact with it.
It’s very easy for me to tell a student that, “hey, at 80 kph you’re travelling 22.22 metres every second” but until you see that distance measured out in hard terms – 5 metre concrete slabs end on end with witches hats marking out the lane down which a car will travel at 80 kilometres per hour then slam on the brakes – 22.22 metres per second means nothing. A cricket pitch is 20.12 metres long. Try running the length of a pitch & see how long it takes at full belt. Then add 2.1 metres and begin to realise how much energy is tied up in a moving body at the pace a human being can cover 22.22 metres. Now translate that to – say, my own car, a Kia Rio Hatch which weighs 1.224 metric tonnes with me on board. That’s 1.224 tonnes moving forward at 80 kph, covering 22.22 metres EVERY SINGLE SECOND.
There’s a physics calculation we were introduced to yesterday which aids is measuring the kinetic energy stored in a moving body. Ke=½MV2 I could easily go on into the labyrinthine depths of science but suffice to say that if you read enough, say, this for example, you’ll get a pure mathematical example as the end result of the equation. That result bears absolutely zero relevance to standing alongside two cars, at speed, braking at identical points and times, and watching the results. Simply put, speed is a result of energy applied to mass. Energy, according to the first law of thermodynamics, can be neither created, not destroyed. Energy simply transmutes from one form to another. Apply energy, in the form of acceleration from an internal combustion engine to a stationary mass – a car – and you get velocity. The energy of acceleration is converted to velocity. Speed. Reducing that speed requires an amount of energy equivalent to that originally applied, plus the inertia of the mass. The faster you go, the more energy, times the mass moving at that velocity, is required to stop it.
As drivers we forget about such prosaic concepts and simply rely on our brakes. Great things, Anti-Locking Braking systems, but they are only as good as our understanding of how they work, what they’ll do under certain conditions, and just exactly how we should, or should not, use them. Bottom line, and the crux of this post is simply this. If you thought 2 seconds at any speed was sufficient to pull you up in an emergency stop, to keep you from hitting the object in front of you, you’re dreaming. Add in human reaction time. That 1.5 to 3 seconds during which you see, interpret and react to the situation you’re presented with. A really good driver at his or her peak of performance will take between 1.5 and 2 seconds to react. In that time, at 80kph, he/she has travelled between 33 metres and 45 metres. That’s BEFORE brakes are applied. Have a look at this example. In fact, read it several times. The faster you go, the more time and distance you need to reduce the energy and momentum of velocity to zero. Braking distance increases by 4 times, when you increase the velocity of the car by two.
Measuring following distances by counting “one second once, one second twice” will only give you absolute minimum braking distance at any speed. Add in reaction time of anything from 2 to 4 seconds and even the rawest of rookie drivers will soon understand the need to drop back from the vehicle in front on any road, simply in order to stay in one piece, alive and with their car intact. Sadly, very few drivers understand this very simple concept. We rely on brakes far too much. As good as computer controlled braking systems are in modern cars, they can only ever be as good as the brain behind the foot over the brake pedal. I don’t have access to a skid pan, nor the network of off-road bitumen track ways that Roadworks Driver Education has. I can’t show new drivers in graphic detail just how a car moves or brakes at speed. I can talk about it until I’m blue in the face, but until a driver sees first hand what I’ve just written about, they will never truly understand. I cannot commend post license training for every driver at Roadcraft enough.