The Hurt Study Revisited
by Dirk Koenig
Why motorcycles crash and what this means to you.
My first exposure to Professor Harry Hurt was an article in Rider Magazine at the very beginning of my motorcycling experience. In one of the current events articles, or in a Lawrence Grodsky safety article, there was reference to a large safety conference that was held in Southern California. In the article, there was a detailed report about the address delivered by one Harry H. Hurt. At first I though it was a joke.
Was it possible that a guy talking about motorcycle accidents could have a name like Hurt? Like McGruff, the Crime Dog, I thought that he was a mascot, a figure whose name or likeness coalesced a group of like-minded individuals and gave them representation. “Ha ha,” I thought, “the safety guys have a mascot.” Well, it turns out I wasn’t far from the truth.
Over time, I began to hear more about this Harry Hurt character and the important work he had done. I learned that he had conducted some research to figure out why and how motorcyclists crashed, and what could be done to reduce the numbers of accidents involving motorcyclists. I never gave it much thought after that. Later, I learned that he and his team of researchers had raced on-site to reported motorcycle accidents and evaluated the accident scenes and talked to the involved parties. Later still, I heard that most of the safety courses being taught had somehow been developed or revamped to make use of the important information from this “Hurt Study.”
It wasn’t until I became an Instructor Candidate for the Minnesota Motorcycle Safety Center in 1995 that I realized what all the commotion was about. As part of my orientation for the Instructor Preparation Course, I was handed a copy of the findings of the Hurt Study. There were 53 individual findings based on the 900 on-site accident studies done and the 3600 accident reports that had been reviewed. In January of 1981, the findings were presented in their final form in the Motorcycle Accident Cause Factors and Identification of Countermeasures report, informally referred to as The Hurt Study. I was fascinated by the conclusions. Some of them were statistically “less than significant” and some of them were a bit dated. The report was published in 1981; the research had been conducted in 1979 and ’80, and therefore still had a “bell bottom” feel to it. But the facts are still useful today, and even some of the dated items, at their root, are still meaningful. The full report is several hundred pages, and is available in printed form. The ordering information can be found at the end of this article.
Note: it may seem that this is a wordy advertisement for motorcycle rider training. In some ways, it probably is; but that’ll be incidental to the subject matter. I’m a guy with a keen interest in safety. I feel that rider training is the single most important factor in accident reduction. That’s why I’m an instructor, and that’s why I’m writing this article. It took me almost 6 years of riding before I really knew what the Hurt Study was all about. The information would’ve been useful to me in my formative riding years. What follows is the list of findings (in bold) in unadulterated form, along with supporting information and my comments:
Approximately three-fourths of these motorcycle accidents involved collision with another vehicle, which was most usually a passenger automobile.
Approximately one-fourth of these motorcycle accidents were single vehicle accidents involving the motorcycle colliding with the roadway or some fixed object in the environment.
Here we go: 100% of the accidents involved a rider crashing. On a related note, of the 40 motorcycle fatalities in Minnesota in 1998, the majority (62%) were single vehicle accidents.
It should also be mentioned that the term ‘accident’ has been supplanted in the safety community with the term ‘crash’. The connotation of the word ‘accident,’ it is felt in these circles, is that the rider had no recourse or chance of avoidance, and use of the term ‘crash’ properly reflects the concept that rider responsibility, not luck, is at the heart of every incident. And they’re right. I’m a strong subscriber to the “There’s no such thing as a faultless motorcyclist” theory when it comes to crashes.
Vehicle failure accounted for less than 3% of these motorcycle accidents, and most of those were single vehicle accidents where control was lost due to a puncture flat.
Newer motorcycle tires are of the radial variety. Most of the tires during the Hurt Study were of a bias-ply type. Radial tires are far less prone to catastrophic failure. Nowadays, most likely, you’ll walk out to your motorcycle in the morning to find the tire has gone flat.
In the single vehicle accidents, motorcycle rider error was present as the accident precipitating factor in about two-thirds of the cases, with the typical error being a slide out and fall due to over braking or running wide on a curve due to excess speed or under-cornering.
These statistics are further verified by looking at the fatality reports. Most commonly, a rider fails to turn tightly enough and runs off the road. If the rider realizes this in time, he or she may choose to overbrake and lock up the rear tire to hasten their meeting with the pavement. This is rider error in its most common form.
Roadway defects (pavement ridges, potholes, etc.) were the accident cause in 2% of the accidents; animal involvement caused 1% of the accidents.
Animal involvement in Minnesota may be somewhat more prevalent, I think. Country roads at dawn and dusk can harbor deer and other fuzzy creatures ready to jump out onto the roadway at the flicker of a single headlight. However, since most traffic travels on urban surface streets, the statistics for crashes are probably reasonably close to the truth. But watch out on those rural roads anyway.
In the multiple vehicle accidents, the driver of the other vehicle violated the motorcycle right-of-way and caused the accident in two-thirds of those accidents.
The failure of motorists to detect and recognize motorcycles in traffic is the predominating cause of motorcycle accidents. The driver of the other vehicle involved in collision with the motorcycle did not see the motorcycle before the collision, or did not see the motorcycle until too late to avoid the collision.
This shouldn’t be surprising. We all know about the “Officer, I just didn’t see him!” argument. The only thing that has changed in 20 years is that it’s somewhat more likely for today’s motorist to say, “Officer, I just didn’t see her!” As an instructor, there are very few incidents where I can justifiably remove all responsibility from the rider. A good visual lead, constant scanning and sensible lane usage can minimize the need for evasive maneuvers, and good motorcycle handling skills can further reduce the chances that those evasive maneuvers will fail. Ultimately, these skills reduce the probability of having to fill out accident reports.
Deliberate hostile action by a motorist against a motorcycle rider is a rare accident cause.
As much as we’d like to believe that they’re out to get us, it’s usually not true; it’s the unusual and startling cases that seem to get the most attention in the media.
The most frequent accident configuration is the motorcycle proceeding straight, then the automobile makes a left turn in front of the oncoming motorcycle. Intersections are the most likely place for the motorcycle accident, with the other vehicle violating the motorcycle right-of-way, and often violating traffic controls.
This is nothing new to motorcyclists who have spent a season in the saddle. Intersections are the most dangerous places for motorcycles to travel. So it has been, and shall always be. Extra caution is warranted.
Weather is not a factor in 98% of motorcycle accidents.
Here’s a shocker. Most riders are fair weather friends anyway. I would imagine that most riders who choose to ride in the rain have some experience doing so. In my experience as an instructor I’ve regularly seen students who were shocked that a motorcycle can be ridden in the rain without falling down. It can be done, and should be practiced, especially by riders who do longer tours and stand a higher chance of being caught in a heavy rain.
Most motorcycle accidents involve a short trip associated with shopping, errands, friends, entertainment or recreation, and the accident is likely to happen in a very short time, close to the trip origin.
Professor Hurt also posited that ninety percent of all motorcycle crashes happen within the first hour of riding; fifty percent happen within the first six minutes. Also note that in Minnesota, the lion’s share of motorcycle crashes happen during the rush hours, particularly in the evening. It seems the factors involved here are attention and concentration on the riding task.
The transition from house to bike, or bike to store, or store to friend’s, is high risk. How long does it take to unwind after work? How focused on traffic hazards are you when you’re mind is somewhere else? Six minutes of riding time after leaving the house is the average time until impact. (This includes the two seconds you’ll have between the time you see the left-turning car and the splat!)
The view of the motorcycle or the other vehicle involved in the accident is limited by glare or obstructed by other vehicles in almost half of the multiple vehicle accidents.
Conspicuity of the motorcycle is a critical factor in the multiple vehicle accidents. Accident involvement is significantly reduced by the use of motorcycle headlamps (on in daylight) and the wearing of high visibility yellow, orange or bright red jackets.
So, visibility is an issue. Lane positioning is critical to see cars and for car drivers to see you. Sun glare is another matter, but good eye protection in the form of a tinted helmet visor or sunglasses (which protect you not only from the sun but also the wind) will at least help you see the other vehicle, even if the driver can’t see you.
Since motorcycles in Minnesota MUST have a headlight on at all times, that’s no longer as much of an issue. Brightly colored clothing and retro-reflective material is still a good idea, and is relatively inexpensive. Even a bright blue or red wind shirt over your bad-ass black leather jacket, especially on the morning and afternoon commutes, will enhance your chances of being seen. As a bonus, it’s small enough so you can tuck it in your briefcase or satchel to retain your bad-ass leather jacket look all the way from the parking lot to your office.
Fuel system leaks and spills were present in 62% of the motorcycle accidents in the post-crash phase. This represents an undue hazard for fire.
The median pre-crash speed was 29.8 mph, the median crash speed was 21.5 mph, and the one-in-a-thousand crash speed is approximately 86 mph.
When motorcycles fall over, gasoline often comes out. I spill gasoline filling my lawnmower and have never caught fire. Avoid smoking or playing with matches around either situation. The speed thing is interesting, though. Most people were going around 30 miles per hour (if my math is correct, that’s 44 feet per second) when something jumped out at them, and had approximately two seconds between the time they detected the hazard and impact. That’s 88 feet they have to work with. A trained rider can reduce speed from 25 mph to a standstill in 34 feet. Easily.
The typical motorcycle accident allows the motorcyclist just less than two seconds to complete all collision avoidance actions.
Two seconds is less time than it takes to read this sentence.
The typical motorcycle pre-crash lines-of-sight to the traffic hazard portray no contribution of the limits of peripheral vision; more than three-fourths of all accident hazards are within 45 degrees of either side of straight ahead.
Seventy-seven percent, according to Dr. Hurt, will come from the 10, 11, 12, 1, and 2 o’clock positions as the rider is traveling. The area behind you, where your loud pipes typically point, accounts for about 3% of impacts.
Conspicuity of the motorcycle is most critical for the frontal surfaces of the motorcycle and rider.
Considering what we know about where accidents are likely to take shape, it stands to reason that being able to see the front of the bike is important. This includes the rider, and his or her brightest colored jacket and helmet.
Vehicle defects related to accident causation are rare and likely to be due to deficient or defective maintenance.
I once heard a story from a friend of mine about a group of riders who were enjoying lunch along the route of one of their favorite rides. As they were preparing to leave, a passer-by that had been enjoying some alcoholic beverages stopped to admire the late-model touring and sporting motorcycles. He was overheard to say “Doesn’t anybody ride JUNK anymore?” The fact is that people DO still ride junk, but crashes aren’t typically caused by bikes that fall apart while in motion.
Motorcycle riders between the ages of 16 and 24 are significantly over-represented in accidents; motorcycle riders between the ages of 30 and 50 are significantly underrepresented.
In the fatality reports for 1998 and 1999, these figures are not necessarily borne out. While younger riders are certainly highly represented, there is plenty of evidence that the 30 to 50 set is out and about, and getting killed on all varieties of bikes.
Although the majority of the accident-involved motorcycle riders are male (96%), female motorcycles riders are significantly over-represented in the accident data.
Here’s another statistic that could wind up being a load of crap. More and more women are riding today. It’s obvious from my classes that many of them are conscientious and skilled, or will be, with practice. In the fatality reports reviewed, none of the riders killed were women. There were, sadly, some female passengers who showed up in the reports.
I’d like to note that I haven’t continuously referred to the fatality reports simply because they support my arguments. There are more than a thousand motorcycle crashes each year in Minnesota, from 2,100+ in 1987 down to 1,131 in 1996, and these are difficult to sort through. There were 40 fatalities in 1998 and 29 in 1999. These are representative of the types of crashes that take place, although they do represent the most serious of those crashes in terms of results. (So I’m not morbid…just lazy.)
Craftsmen, laborers, and students comprise most of the accident-involved motorcycle riders. Professionals, sales workers, and craftsmen are under-represented and laborers, students and unemployed persons are over-represented in the accidents.
I’m not sure these are statistically relevant facts. At the time this study was done, motorcycling was still the choice of the frugal and the young. There is currently a trend toward street riding as a hobby, rather than as transportation. As a college student in the late ’80’s and early ’90’s, I can assure you that I had neither adequate brains nor a full-time job to keep me out of trouble. Draw what conclusions you will. As a technology professional, motorcycle enthusiast and safety expert, I feel I know what I’m doing, but I’m still a hooligan at heart. Bear in mind that more dentists, doctors, and lawyers are found riding around on weekends than ever before, and many of them choose not to learn motorcycling skills through training.
Motorcycle riders with previous recent traffic citations and accidents are over-represented in the accident data.
If you’ve earned yourself multiple traffic tickets, you’re probably more likely to be riding too fast for conditions, or riding without the safety of yourself and others in mind. This is understandable and is predictably still true.
The motorcycle riders involved in accidents are essentially without training; 92% were self-taught or learned from family or friends. Motorcycle rider training experience reduces accident involvement and is related to reduced injuries in the event of accidents.
OK, we’re back to my element here. I learned to ride in a church parking lot; my mentor was just some guy I knew. Not so smart. (See above.) Not long after this, I was following him around on my very own bike; fifteen minutes of instruction, then from church parking lot to freeway. Most experienced riders who’ve taken my class figured they wouldn’t learn anything, and most of them were (happily) surprised to find out that there were simple tricks that had never occurred to them and critical skills that they were lacking, and needed to learn and practice. Get some training.
Take an Experienced Rider Course! (Statistically, it would be irresponsible to attribute motorcycle crashes directly to a lack of training. To be fair, skills training is definitely a factor, but other factors, primarily, the safety-minded attitude of the rider who takes the training, probably has as much of an impact on crash probability and injury reduction as the training itself.)
More than half of the accident-involved motorcycle riders had less than five months of experience on the accident motorcycle, although the total street riding experience was almost three years. Motorcycle riders with dirt bike experience are significantly under-represented in the accident data.
This isn’t surprising either. When you get a new bike, it takes time to learn how it handles and performs. Be careful when switching to a larger or more powerful bike, as its performance may surprise you. Also, when switching to a smaller bike, be aware that the neck-snapping acceleration you were used to may be gone. Practice and care is essential.
Lack of attention to the driving task is a common factor for the motorcyclist in an accident.
Not surprisingly, this is a common factor in all types of crashes. Motorists who are talking on the phone, applying cosmetics, reading or dining while driving are all at risk for involvement in roadway unpleasantness. At least motorcyclists (unlike car drivers) are more or less unable to perform most of these tasks. Pay attention while riding.
Almost half of the fatal accidents show alcohol involvement.
True in 1980, but since then, the national average for motorcycles has dropped to about thirty-nine percent. In Minnesota, however, the average hovers at an alarming fifty-seven percent.
Motorcycle riders in these accidents showed significant collision avoidance problems. Most riders would over-brake and skid the rear wheel, and under-brake the front wheel, greatly reducing collision avoidance deceleration. The ability to counter-steer and swerve was essentially absent.
Oddly enough, non-alcohol impaired riders have similar problems. NOT consuming alcohol doesn’t give you these skills, but it does take them away if you ever had them in the first place.
This finding is the primary reason that the Motorcycle Safety Foundation developed the Riding and Street Skills (the basic course) and the Experienced Rider Course (ERC) the way they did. The skills indicated here…braking, swerving and counter-steering…are taught and practiced, as well as cornering and tight-turn techniques. All are covered in both the basic course and the ERC.
We’ve looked at about half of the conclusions from the Hurt Study so far. Already, I think, you’re getting a feeling for the findings. I often wonder what it must have been like to visit the scenes of so many crashes where people were injured or killed, only to find the same scenario played out over and over again: riders with limited skills or under the influence of alcohol failing to perform evasive actions or performing them incorrectly in common traffic accident scenarios.
Next month we’ll take a look at the rest of the findings and see what else can be learned from this effort.
If you’d like to get a copy of the entire Hurt Report, the order information is as follows:
Motorcycle Accident Cause Factors and Identification of Countermeasures, Volume 1: Technical Report, Hurt, H.H., Ouellet, J.V. and Thom, D.R., Traffic Safety Center, University of Southern California, Los Angeles, California 90007, Contract No. DOT HS-5-01160, January 1981 (Final Report)
This document is available through: The National Technical Information Service, Springfield, Virginia 22161