Motorcycle Council of NSW Ph: 1300 679 622 (1300 NSW MCC) |

Speed as a Causal Factor in Crashes

Position Statement – Speed as a Causal Factor in Crashes

The basis for determining the number of crashes where speed is a causal factor is flawed.

Priority:- High

Where we are now:

NSW Road authorities claim that “speed” is the biggest killer on our roads, claiming that speed is a causal factor in 40 % of crashes. The MCC does not agree with this claim as it is not substantiated by any factual/evidence-based investigative findings.

The basis of this claim is Police reports that are prepared by General Duties Police who are not trained specialist crash investigators. Such reports, whilst ensuring an accurate outline of WHAT happened in a crash, often fails to discover WHY the crash happened. Consequently little or no reliable crash cause data is gleaned from police attendance at road crashes. Police routinely do their best to work out WHAT was involved in crashes that they attend so that they may provide basic evidence of the commission of any traffic offence/s that has/have occurred in the crash. Thus the purpose and extent of any ‘investigation’ that takes place at a crash is designed to suit traffic offence prosecutions and in the case of serious traffic crashes, the possibility of criminal offences – rather than any effort to determine and/or better understand actual crash causation.

Only fatal and serious injury are attended by police with experience in criminal investigation and they may also have assistance from scientific sources but even then, such attendance, whilst ensuring an accurate outline of WHAT happened in a crash, often fails to discover WHY the crash happened.

Algorithms are then used to interrogate Police Reports to determine if ‘speed’ as a factor in the crash. These algorithms over estimate the role speed plays in crashes, in particular, motorcycle crashes.

In the United Kingdom (UK) for example, specially selected and educated police conduct road crash investigation and these police do NOT initiate prosecutions for traffic offences, as is the case in NSW. The UK crash investigation police focus on ‘causation’ as their key task. In the UK back in 1997, the British Transport Laboratory undertook a project (TRL323) to better standardize reporting of road crashes throughout the UK and following this project that thoroughly re-examined road crashes in 8 policing jurisdictions in the UK, they found that less than 8% of all road crashes involved exceeding speed limits as a causal factor. Report TRL323 clearly identified driver ‘inattention’ as the biggest causal factor in road crashes.

In the USA in 2005, the National Highway Traffic Safety Administration, in conjunction with Virginia Technical University, conducted a long-term “Naturalistic Driving Study”, involving over 42,000 thousand hours of captured in-car footage from 100 participant cars and 241 drivers. The results of this study showed that excessive speed was a causal factor in just 7% of ‘adverse incidents’ recorded. However, the study showed that almost 80% of adverse incidents involved driver inattention just prior to the incident (ie within 3 seconds). Prior to this study (in a similar mind-set to NSW Road Authorities), driver inattention was thought to have been a causal factor in around 25% of adverse traffic incidents.

“Speed” is a factor in every single road crash (ie 100%) when it comes to OUTCOME but “speed” is rarely the actual CAUSE of a road crash. Sound international research has already long established this fact. Thus the claim that speed is a factor in 40% of fatal crashes is a meaningless statement because the statement is silent on whether the factor being referred to is one of OUTCOME or CAUSE. NSW road authorities need to start providing for proper cause-driven investigations of road crashes instead of perpetuating misleading statements that have no basis in fact.

Where we want to be:

That road safety authorities to implement proper road crash investigation with the key purpose of understanding true crash causation and to cease the current inept methodology of road crash cause ‘determination’ by the application of contrived causal criteria to current road crash reporting, such criteria that do not provide evidence-based data with respect to road crash causation. Prosecute traffic offenders involved in road crashes – but even more importantly, determine the cause of the crash.

How to get there: