If you can’t see it, does that mean it isn’t there?
“Absence of proof is not proof of absence”
William Cowper 1731-1800
A claimed advantage of the early automobile was its apparent insensitivity to running away, as reflected in this report in the Los Angeles Times of 1901:
“Los Angeles policemen are beginning to figure to what extent the supplanting of the horse by the automobile is going to lessen their chances to win glory. The policeman’s most frequent opportunity to distinguish himself is afforded by runaway horses. There is not an experienced officer on the force who has not won honorable mention at one time or another by stopping a team. The acts of the police in this respect are at times indeed heroic. More than one officer has imperilled his life in the effort to prevent a runaway.”
Isn’t it, then, rather odd that 21st century automobiles, with their electronically controlled engines – nominally better controlled than their simpler, 20th century all-mechanical counterparts – should occasionally run away with horrific consequences? Could the problem lie in the electronics? Not so, claim the manufacturers, who blame drivers, loose floor mats and sticky accelerator pedals.
With an electronic throttle the accelerator pedal is no longer mechanically connected to the throttle; it sends electrical signals to the engine control computer (ECU). The ECU notes the driver’s ‘request’ and, taking account of many other signal inputs, computes an appropriate throttle angle and commands the throttle to move accordingly. The ECU, not the driver, now controls the throttle.
That fundamentally alters the relationship between the driver and the vehicle, a fact not yet recognised by the law.
In some circumstances an electronic throttle may exhibit a ‘will of its own’ and without any driver input may act unpredictably and sometimes dangerously. Sudden acceleration incidents – unknown prior to the introduction of electronic speed control systems in the mid-1970s – have markedly increased since the introduction of electronic throttles (circa 2002). History has gone full circle, with police occasionally chasing and corralling a modern runaway electro-mechanical horse.
Intermittent electronic malfunctions – often caused by electromagnetic interference or software glitches – leave few traces and are notoriously difficult to diagnose. Attempts to reproduce the malfunction by workshop or road testing are usually fruitless. However, failure to diagnose or reproduce the malfunction does not mean that it never occurred.
Unfortunately, in the courts absence of proof may be accepted as proof of absence, ie if no physical evidence of an electronic malfunction can be found it must have been the driver. By such fallacious argument, the vehicle rather than the driver is assumed innocent unless proved guilty. As a result, a number of drivers have been tried and convicted for vehicular homicide, in one case receiving a prison sentence of 15 years (Mary Hill case, Orlando, Florida: 2003).
With the increasing application of safety-critical electronic control systems in automobiles, the number of deaths, injuries, wrecked lives and wrongful convictions is likely to increase. Unless, that is, a strong regulatory framework for the electronic age is put in place to ensure that car makers are subject to similar stringent safety requirements to those that already apply in the nuclear, aircraft, railway and other industries.
One of the likely outcomes of US Congressional Sub Committees currently enquiring into automobile sudden accelerations is a regulatory framework designed for the electronic age. The US Department of Transportation has in my opinion made a good start by asking the US National Academy of Sciences to investigate sudden accelerations in all vehicles and NASA to examine the onboard computers in Toyota vehicles.