Traffic Safety by Leonard Evans published in 2004 remains a classic. It identifies three factors implicated in all road crashes: human, roadway engineering, and automotive engineering factors. Despite the passage of years and alternating statistical trends, Dr. Evans’ scientific analysis of each of these factors has remained consistent.
Human factors vs. Engineering factors
In June 1996, for example, in the American Journal of Public Health he wrote, “the core traffic safety research finding [is] that changes in driver behaviour offer, by far, the largest opportunities for harm reduction. A clear hierarchy of factors can be specified. Human factors are far more important than engineering factors. Among human factors, driver behaviour (what the driver chooses to do) has a much greater influence on safety than driver performance (what the driver can do).
Among engineering factors, roadway engineering has much greater influence than automotive engineering. The fatality rates on some road categories are eight times that on others. In contrast, after controlling for driver behaviour, vehicle mass, and vehicle model year, no clear differences in overall safety have been found between cars.”
Poor driving performance
Eighteen years later, in a 2014 article published in USA Today addressing the first increase in 20 years in the US NHTSA statistics on highway fatalities, Dr. Evans reaffirmed that the human factor far outranks engineering factors as the cause of harm on the roads noting that “the US, when compared with other industrialized countries, is utterly failing to adequately tackle highway safety” and has been failing to do so since 1972, the point of highest recorded deaths on the road when, although the number thenceforth began to decline in the US, did so at a rate “less than in 25 other countries.”
The reason for this poor driving performance, says Dr. Evans, is “safer countries focused on changing driver behaviour to reduce the risk of crashing, while the US has been hyper-focused on technology, particularly mandatory improvements designed to mitigate harm after a crash occurs, and vehicle defects.”
Road safety depends on the human factor
Dr. Evans’ conclusion that the human factor in road safety is overwhelmingly important suggests how the issues currently ‘trending’ in the road safety academy should be prioritized. ‘Bold’ roadway engineering initiatives may be in the works. For example, road tolling in Toronto on existing long-paid-for infrastructure is being advanced to reduce congestion and fund other transit initiatives.
In many countries infrastructure to facilitate ‘intelligent’ vehicle-to-vehicle-to-road communication is being tested partly in preparation for the not-far-off arrival of self-driving vehicles. But, clearly, for now, two of the most pressing ‘human factor’ issues, namely distracted driving and drug-impaired driving should be top of the list.
No one is more emphatic on the issue of bad driving than Leonard Evans himself (writing in USA Today 2014): “As we know from the experience of other countries, vastly more important than the vehicle factors constantly in the news (vehicle defects, recalls, crash ratings, etc.) are interventions that have proved more effective — radar-speed detectors and red light cameras, stricter laws against driving while distracted, etc. The way to cut in half the present mass killing on our streets and highways is quite simple: sensible traffic safety laws sensibly enforced in ways that the public welcomes.”
Road Rules by Cedric Hughes and Leslie McGuffin