Motorcycles and the Statistics of Death**

*Chicago Tribune
April 15, 2011
as "Motorcycles and statistics"

*Somerset, PA  Daily American
April 16, 2011
as "Motorcycles and statistics"

Copyright © 2011 by Ralph Couey

Since my accident two years ago, my colleagues have taken a sincere interest in my safety. This past week, out of that concern, they deposited the latest edition of the Journal of Forensic Science on my desk. One might characterize this publication as the pinup magazine for Coroners.

Three articles were bookmarked. One was entitled, “Massive Lesions Owing to Motorcyclist Impact Against Guardrail Posts.” Another article was “Traumatic Testicular Displacement in Motorcycle Drivers.”

Ouch.

The third one, however, was the most interesting. “Death by Motorcycle: Background, Behavioral, and Situational Correlates of Fatal Motorcycle Collisions.” This was an impressive statistical study done by Dr. Samuel Nunn, Professor of the School of Public and Environmental Affairs and Director of the Center for Criminal Justice Research, part of the Indiana University-Purdue University of Indianapolis.

Like many professional journal articles, this one needed to be read with a dictionary and thesaurus close at hand. And while the science of statistics is still a bit of a mystery to me, there were enough plain-language findings in the paper to get my attention.

The data for this study came from 18,225 fatal motorcycle crash reports from law enforcement agencies in the state of Indiana between 2003 and 2008, including deaths that occurred within 30 days of their accident. In analyzing those reports, Dr. Nunn developed these dominant factors:

• 87% of victims were men

• 50% of fatalities occurred on Friday, Saturday, or Sunday

• 60% of deaths occurred in rural areas.

• 66% of fatalities involved helmetless riders.

• Over half of the fatal crashes (51.5%) were collisions with other motor vehicles.

• Another 28.4% of cases involved the rider losing control of the bike.

(Those last two factors accounted for over 80% of deaths.)

Some of the findings I already knew, like the fact that “motorcycles were 27.5 times more likely to be part of a fatal collision than passenger cars,” and that the most common agent of death was “severe blunt force trauma.” These are obvious facts to anyone who rides.

The study determined three fundamental causes of death:

1. Collision with another motor vehicle

2. Collision with another stationary or moving non-vehicular object

3. Some other harmful action by motorcyclists

Another sobering finding was that drug use increased the odds of death by almost 30%. Dr. Nunn stated, “The presence of drugs contributed significantly to serious injury.” Alcohol was next at 11.1%.

For non-vehicular collisions, trees were the most deadly point of impact. For vehicular collisions,  a significant factor involved the bike crossing the centerline.

Higher speeds increased the odds of death. However, a surprising finding was that lower fatality odds occurred on wet roads, mainly because riders generally go slower in the rain. In foggy conditions, the odds of dying were nearly doubled. Darkness was significant in several ways. Riders were more likely to engage in risky riding habits in the dark. Also, they were more likely to have been drinking or doing drugs prior to riding.

The odds of dying in a motorcycle accident increase by about 1.5% for each year of aging.

Dr. Nunn states emphatically, “Helmet use drives down the odds of death.” This finding, added to the recent study done by the Johns Hopkins University School of Medicine showing that modern helmets actually decreased cervical spinal injury, point to the obvious benefit of wearing the brain bucket. He concedes, however, that in some cases, the forces involved in some collisions, especially ones involving high speed, will result in death regardless of safety gear, or the lack thereof.

Adding all these factors together, Dr. Nunn concluded that the most likely scenario of death involves men, 21- to 44-years old riding in the dark from Friday to Monday, with a reasonable suspicion that those riders were chemically impaired.

One gap in this study involved deer strikes. A lot of riders cross swords or antlers as it were, with Bambi and his friends, particularly between dusk and dawn. I would have expected some discussion of this hazard, especially in data from Indiana.

Statistics can be cold, and certainly will never properly express the tragedy of traumatic human death. But Dr. Nunn has gone a long way towards identifying those things that place riders at the highest risk.  If the riding community takes note of these higher risks, then we can take to the roads better prepared to make it home in one piece.

And forewarned is always forearmed.