Leonard Evans President, Science Serving Society Bloomfield Hills, MI USA Reducing Traffic Injury Past Research Achievements and Opportunities for a More Productive Future Devoted to adding reason and knowledge to public policy Ottawa, Canada Tue 26 May 2015

Bow of Titanic – 4 km under Atlantic Ocean. Photographed 2 Sept by Leonard Evans

Summarizes what science has taught about traffic safety

Titanic illustrates central distinction between:- 1. Crash protection Given crash occurs, to reduce consequent harm 2. Crash avoidance To prevent crash occurring Did Titanic’s superior crash protection  save 705 lives, or  cause over 1500 deaths?

Early recognition of distinction between 1. Technology 2. How it is used – driver behavior

Now look at peer-reviewed technical literature Paper in Am. J. Psychology All previous anecdotal

More efficient brakes on an automobile will not in themselves make driving the automobile any safer. Better brakes will reduce the absolute size of the minimum stopping zone, it is true, but the driver soon learns this new zone and, since it is his field-zone ratio which remains constant, he allows only the same relative margin between field and zone as before. A Theoretical Field-Analysis of Automobile Driving, American Journal of Psychology 1938

Claim that better brakes do not increase safety based on reason alone But is it possible to address empirically? Did not happen in 1940s 1950s 1960s 1970s 1980s then opportunity occurred!

Dramatic advance in brake technology Increases rollover risk by (39+16)% Large numbers of GM popular vehicles: 1991 MY – NONE had ABS 1992 MY – ALL had ABS Otherwise, no important differences ABS (antilock brakes)

 Much of our understanding of safety from events that cannot be repeated  Belt laws – UK  Belt effectiveness – US  Motorcycle helmet effectiveness (US) ( like belt effectiveness)  Helmet laws – enactment and repeal - US  NSW random-breath testing followed by drop in casualties  Effect of alcohol on crash risk  55 mph speed limit – after Oct Mid- E war  Safety research often more like astronomy than physics - we can just observe, not perform experiments  Observable events of high value are rare EXAMPLES

Legal limit in all US States

Named for town in Michigan Performed by Robert Borkenstein and colleagues

5.8 mph decrease

Observed 34% decrease

 But also much from studies that CAN be repeated Replication is at the heart of science The scientific value of replicating and extending many prior studies far exceeds that of much original research  Much understanding from events that cannot be repeated

“Finch and Smith [1970] applied an imaginative technique to obtain psychiatric profiles of 25 deceased male drivers judged to be at fault in the crashes in which they were killed in Houston from ” Psychiatric profiles of fatally injured drivers Traffic Safety and the Driver (1991), p.145-6

road user road user road environment road environment vehicle US GB road user road user road environment road environment vehicle US GB road user road user road environment road environment vehicle /3495/948/ US GB road user road user road environment road environment vehicle US GB Both studies performed in 1970s US study supported by NHTSA

Williams AF, O'Neill B. On-the-road driving records of licensed race drivers. Accident Analysis and Prevention 1974 ;6:

Published 1997

Effects of speed 1. Risk of crashing increases with increasing travel speed 2. If crash occurs, risk of injury increases with increasing speed 3. If injury occurs, risk that it is fatal increases with travel speed 1% increase in travel speed increases the risk of a fatal crash by at least 4%

Some studies of mine that invite replication and extension

Evans L, Frick MC. Alcohol’s Effect on Fatality Risk From a Physical Insult. J Stud Alcohol. 1993;54: Based on FARS

FARS = 14 data years Starting now, FARS = 40 data years This does NOT merely represent a 40/14 = 2.85 times increase in data, because more recent data have more BAC information

How safe were today's older drivers when they were younger? Am J Epidemiology. 1993;137: “A longitudinal analysis using the much longer series of FARS data now available would provide useful new information.” Traffic Safety (2004), p. 161 FARS

age 26 (FARS 1975) Blue curve is for cohort of drivers born in 1949 (+ 2) age 41 (FARS 1990) age 65 (FARS 2014)

Predictions Never make predictions — especially about the future Never make predictions

15 May 2015

Are already safer than human- controlled cars Cannot become universal for many decades System consisting exclusively of self-driving cars can approach perfect safety

New Yorker, , p.63

In the meantime over a million people will continue to be killed annually on the wrolds roads for many decades to come New ‘safety’ technologis may enhance or reduce safety Apart from self-driving cars, in-vehicle electronics has little to offer

New Yorker, , p.50

New Yorker, , p.80 New on-board electronic devices invite more distraction

Any man who can drive safely while kissing a pretty girl ….. Any man who can drive safely while kissing a pretty girl is simply not giving the kiss the attention it deserves Albert Einstein

Ongoing problems  Older drivers  Pedestrians  Male drivers Far more radar-speed detection and red- light cameras ‘Sensible traffic law sensibly enforced’

April 2015

Effects of media overwhelming!!  Hollywood?  TV?  Auto advertising? No – I don’t know how to obtain answers. Suggested units for answer – thousands. Can research determine how many annual traffic fatalities are due to: Other research chalanges

Concluding thoughts 11,171 people killed in 2013 traveling in seats “protected” by airbags

Speed Belt wearing Drunk driving Benefits only relevant occupant Affects all road usersAffects all road users, although victim is usually the drunk driver (plus similarly drunk passengers) Affects ALL road users – is central

Science always points to driver behavior at the core of traffic safety

Will leave copies of these two papers Evans L, Frick MC. Alcohol’s effect on fatality risk from a physical insult. J Stud Alcohol. 1993;54: Evans L. How safe were today's older drivers when they were younger? Am J Epidemiology. 1993;137: (also available as pdf files on my web at

I dislike arguments of any kind. They are always vulgar, and often convincing. Oscar Wilde