Before you buy a motorbike

Three quarters of the crashes in the study were collisions with another vehicle, and the single most common one is a car turning across your path at an intersection.

• 3 in 4hit another vehicle

  About three quarters of the crashes were a collision with another vehicle, and that vehicle was usually a passenger car.

• 1 in 4hit the road or an object

  About one quarter were single-vehicle crashes, where the motorcycle hit the roadway or a fixed object with no other vehicle involved.

• The failure of drivers to detect and recognise motorcycles in traffic is the predominating cause of motorcycle crashes. The other driver either did not see the motorcycle before the collision, or did not see it until too late to avoid one.

  This is the finding the whole report turns on. You are not competing with drivers who saw you and misjudged. You are dealing with drivers who looked and did not register you.

• 2 in 3of multi-vehicle crashes

  In the multi-vehicle crashes, the driver of the other vehicle violated the motorcycle rider’s right of way and caused the crash in two thirds of them.

• 2 in 3of single-vehicle crashes

  In the single-vehicle crashes, rider error was the precipitating factor in about two thirds of cases. The typical error was a slide-out and fall from overbraking, or running wide on a corner from too much speed or not enough lean.

  Nobody else is involved in these. They are the crashes you have entirely to yourself, and they are a quarter of the total.

• Halfof multi-vehicle crashes

  The view of the motorcycle, or of the other vehicle, was limited by glare or blocked by other vehicles in almost half of the multi-vehicle crashes.

• Most crashes happened on a short trip: shopping, an errand, visiting friends, entertainment or recreation. The crash usually happened a short time and a short distance from where the trip started.

  The ride to the shops is not the safe one. It is the typical one.

The one to expect

• The most frequent crash configuration is the motorcycle travelling straight ahead and a car turning across in front of it. The report describes this as a left turn, because it was conducted in Los Angeles.

  Where traffic keeps left, the same manoeuvre is a car turning right across you. It is the one to expect at every intersection with an oncoming car that has slowed.

• Intersections are the most likely place for the crash, with the other vehicle violating the motorcycle’s right of way and often violating a traffic control as well.

• < 2 secto do everything

  The typical crash allows the rider just under two seconds to complete all collision avoidance action: see it, decide, and brake or swerve.

• 48 km/hmedian speed before the crash

  The median speed before the crash was 29.8 mph, and the median speed at impact was 21.5 mph. One crash in a thousand happened at around 86 mph.

  That is 48 km/h before and 35 km/h at impact, with one in a thousand at 138 km/h. Most of this happens at suburban speeds, not at speed.

• Riders showed significant collision avoidance problems. Most would overbrake and skid the rear wheel, and underbrake the front, which is where nearly all the stopping power is. The ability to countersteer and swerve was essentially absent.

  The two seconds were there. The skill to use them was not. This is the finding that argues hardest for practising emergency braking somewhere safe, before you need it.

• Lack of attention to the riding task is a common factor for the rider in a crash.

The report compared crashed riders against riders on the road at the same places and times, so it can say which groups turn up in crashes more often than they turn up in traffic.

Over-represented means the group turns up in the crash sample more often than it turns up among riders on the same roads at the same times. It is a direction, not a multiplier: the report does not say by how much for most of these, so neither does this page.

Crashing a motorcycle almost always injures you. The question the report answers is how badly, and where.

• 98% / 96%of crashes caused injury

  The likelihood of injury is extremely high: 98% of the multi-vehicle collisions and 96% of the single-vehicle crashes injured the rider. Forty-five per cent produced more than a minor injury.

  There is no meaningful category of motorcycle crash you walk away from unhurt.

• The most deadly injuries were injuries to the chest and the head.

• Injury severity increases with speed, with alcohol involvement, and with motorcycle size.

• Safety helmet use is the single critical factor in preventing or reducing head injury.

• Helmeted riders and passengers showed significantly lower head and neck injury. There is no liability for neck injury from wearing a helmet: helmeted riders had fewer neck injuries than unhelmeted riders.

  The report tested the argument against helmets directly, and it did not survive.

• Helmet use caused no attenuation of critical traffic sounds, no limitation of the pre-crash visual field, and no fatigue or loss of attention. No element of crash causation was related to helmet use.

• Halfof body injuries were legs and feet

  Half of the injuries to the body were to the ankle and foot, the lower leg, the knee and the thigh.

  Boots and armoured trousers cover the half of the injuries that a helmet and a jacket do not.

• Crash bars are not an effective injury countermeasure. The reduction in ankle and foot injury is balanced by an increase in injury to the thigh, the knee and the lower leg.

• 62%leaked fuel after the crash

  Fuel system leaks and spills were present in 62% of the crashes after the impact.

Worth reading, because these are the things new riders worry about, and the report puts almost none of the risk in them.

• 98%of crashes, weather not a factor

  Weather is not a factor in 98% of motorcycle crashes.

• < 3%of crashes

  Vehicle failure accounted for less than 3% of the crashes, and most of those were single-vehicle crashes where control was lost to a puncture.

• 2%of crashes

  Roadway defects such as pavement ridges and potholes were the cause in 2% of the crashes.

• 1%of crashes

  Animal involvement accounted for 1% of the crashes.

• Deliberate hostile action by a driver against a motorcycle rider is a rare cause of crashes.

• Motorcycles carrying a passenger are not over-represented in the crash data.

Motorcycle Accident Cause Factors and Identification of Countermeasures. H. H. Hurt, J. V. Ouellet and D. R. Thom, University of Southern California Traffic Safety Center, for NHTSA, 1981. Fieldwork ran 1976 to 1980; the findings are section 12.1, pages 416–419.

• The fieldwork ran from 1976 to 1980 in one American city. Traffic law, road design and the mix of vehicles have all moved since.
• No motorcycle in the sample had anti-lock brakes, which is the single largest change to the braking finding: the skill gap the report measured is one that modern brakes partly cover.
• Helmet, jacket and boot construction have all changed. The findings on whether protective gear works still hold; the findings on how well are conservative.
• The report describes right-hand traffic. Turn directions mirror where traffic keeps left, and this page mirrors them where it says so.
• It counts crashes, not risk per kilometre. It says what happens when riders crash, not how likely you are to crash.

• The report itselfVolume 1, Technical Report. The findings are section 12.1, pages 416–419. Free, and a large PDF.
• List of findings in the Hurt ReportAll fifty-five findings, in one page, in the report’s own order.
• MAIDS, the European repeatACEM ran the same method over 921 crashes across five European countries from 1999. It supports most of what is above, including that 69% of the other drivers attempted no avoiding action at all.

Speeds are shown in km/h where this page converts them; every figure the report published is in miles per hour and is stated that way too. Nothing you do here is sent anywhere: the findings ship with the page and the arithmetic runs in your browser.