Impaired riding research

Traffic Safety Facts 2001: Motorcycles (PDF)
In 2001, 29 percent of all fatally injured motorcycle operators were intoxicated (BAC 0.08 g/dl or greater). An additional 7 percent had lower alcohol levels (BAC 0.01 to 0.07 g/dl). The intoxication rate was highest for fatally injured operators between 40 and 44 years old (42 percent), followed by ages 35 to 39 (40 percent) and ages 30 to 34 (35 percent). – The National Highway Traffic Safety Administration

Alcohol Use, Driver, and Crash Characteristics Among Injured Motorcycle Drivers by Corinne Peek-Asa and Jess F. Kraus
Although alcohol remains a very important factor in all types of vehicle crashes, it is particularly important in motorcycle crashes. Motorcycle drivers in fatal crashes tend to be legally intoxicated more frequently than drivers of any other motorized vehicle. In addition, motorcycle drivers have the highest alcohol use rates among all drivers. – originally published in The Journal of Trauma, Injury, Infection, and Critical Care, volume 41, number 6, 1996, pp. 989-993

Alcohol in Motorcycle Crashes by N.L. Hayworth (PDF)
A study of 222 ,motorcycle crashes in Melbourne Australia found that having a blood-alcohol concentration (BAC) greater than zero was associated with a five-fold increase in the odds of crashing, compared to a BAC level of zero. The increase in risk associated with a BAC of .05 was about forty-fold. – Monash University, Australia

A Review of the Literature on the Effects of Low Doses of Alcohol on Driving-Related Skills by H. Moskowitz and D. Fiorentino
A review of the scientific literature regarding the effects of alcohol on driving-related skills was conducted. One hundred and twelve articles – from 1981 to 1997 – were reviewed. It was concluded that: alcohol impairs some driving skills beginning with any significant departure from zero BAC; specific performance skills are differentially affected by alcohol; and all drivers are expected to experience impairment in some driving-related skills by 0.08 g/dl or less. – The National Highway Traffic Safety Administration

Motorcyclist Alcohol & Other Impairment
Alcohol and other substances have been found to be major risk factors in all types of motor vehicle crashes. These factors appear to weigh more heavily in motorcycle crashes than in crashes of other vehicle types. – The National Agenda for Motorcycle Safety