The Transport Accident Commission (TAC) is a government road accident insurer in Victoria Australia. It is involved in the promotion of behavioral initiatives including the issue of vehicle speed particularly in this example about motorcycles.
Their speed campaigns are backed by “science” according to the Commission. They tell us about The “Science” and Research behind the Campaign.
As in Selective science in road risk: energy and speed cameras from another government department the TAC invoke the credibility of “science” in explaining their campaign but if the surface is scratched it is not credible.
In the paragraph headed “What is the relationship between speed and crash severity?” it explains that a moving body possesses kinetic energy. True. It explains twice that the kinetic energy is proportional to the square of the speed. True. it gives an example that a rider at 60km/hr would have 30% less energy than at 68km/hr. As well as disguising the issue of mass in the energy equation, the TAC can’t even get the mathematics right (see detail here here).
In the “selling of speed enforcement” with the “science of energy” in just two paragraphs the Commission mentions “energy” 13 times and “speed” 6 times. But does not even mention that kinetic energy = 0.5 x mass x velocity squared.
A motorcyclist who actually uses the science of energy would reasonably say, ok, I ride light bike, that means I can go faster. Bikes can easily range from 200 to 400kg. For example a Kawasaki Ninja Zx-6R weighs 194kg versus a Kawasaki Voyager 1700 which weighs 406kg.
The light bike can safely travel faster than the heavier one? Is that what TAC mean? Either the TAC does not know how energy is calculated or chooses to ignore this part of the equation simply because it is inconvenient. Neither of these options make for a scientifically sound argument.
“Science” is used to sell many products. We are perhaps expected to conjure up images of white coats, measurements, mathematics, tests and trials and in particular scientific rigor and of course importantly – truth. But is truth enough if it is not the whole truth? Is it scientific to adopt the motto:
“Tell the truth, part of the truth, the convenient part of the truth”?