According to "Motorcycle Accident Cause Factors and Identification of Countermeasures" (the Hurt Report). This study examined nearly 4,500 crashes occurring in the Los Angeles area and was sponsored in part by NHTSA in 1981.

Motorcycle riders with previous recent traffic citations and accidents are over represented in the accident data.

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. The majority of the accident-involved motorcycle riders are male (96%).

Nearly 75% of the crashes occurring involved motorcycles involved in a collision with another vehicle, which was mostly a passenger car.

The most deadly injuries to the accident victims were injuries to the chest and head.

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 multiple vehicle accidents, and 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.

The use of the safety helmet is the single-most critical factor in the prevention or reduction of head injuries.

Seventy-three percent of the accident-involved motorcycle riders used no eye protection, and it is likely that the wind on the unprotected eyes contributed in impairment of vision, which delayed hazard detection.

The use of heavy boots, jacket, gloves, etc., is effective in preventing or reducing abrasions and lacerations, which are frequent but rarely severe injuries.
Injury severity increases with speed, alcohol involvement and motorcycle size.

The use of the full facial coverage helmet increases protection, and significantly reduces face injuries.

Safety helmet use caused no attenuation of critical traffic sounds, no limitation of precrash visual field, and no fatigue or loss of attention; no element of accident causation was related to helmet use.

There is not liability for neck injury by wearing a safety helmet; helmeted riders had less neck injuries than unhelmeted riders.

Approximately 50% of the motorcycle riders in traffic were using safety helmets but only 40% of the accident-involved motorcycle riders were wearing helmets at the time of the accident.

Almost half of the fatal accidents show alcohol involvement

More than half of the accident-involved motorcycle riders had less than 5 months experience on the accident motorcycle.

The most frequent impact configuration is the motorcycle proceeding straight ahead and the car making a left turn in front of the oncoming motorcycle.
In multiple vehicle accidents, the driver of the other vehicle violated the motorcycle�s right of way and caused the crash in 2/3 of the cases.18.Intersections are the most likely place for motorcycle crashes with other vehicles.