Quantifying the Influence of Social Characteristics on Accident and Injuries Risk: A Comparative Study Between Motorcyclists and Car Drivers

In the recent years many European countries have experienced an increase in the number of fatal traffic accidents with motorcycles. Bos et al. (2008) reports an increase from 17.4% to 21.1% of the total number of fatalities on powered two-wheelers in the European traffic. Several reasons for this have been suggested, among the most common is the hypothesis that during the last decade or so, the typical motorcyclist has become older, and as a result of the increase in age, the loss of physical ability in driving and orientation has resulted in the increase in the number of accidents (Værø 2008, SafetyNet 2009).

In Denmark in the period 2002 to 2007, the average age of motorcycle owners increased from 42.3 to 45.2 years. In the same period, the average age of injured motorcyclists increased from 35.9 to 38.4 years, meaning that the average injured motorcyclist has become younger in this period. In this analysis we establish relationships between social and demographic characteristics and the probability of being in an accident and being injured in an accident.

Logistic regression was applied to both motorcyclists and car drivers with the purpose of calculating the odds ratio with the car drivers as the control group. The available data for the regression consisted of accident and injury data for motorcyclists and car owners in the period of interest as well the social and demographic parameters: age, gender, income, educational level and family status.

The odds ratio calculations showed that the risk of being in an accident or in an injury accident decreased with age, educational level, and income. Furthermore, the risk of being in an accident was 1.72 to 1.96 times higher and the risk of being in an injury accident was 1.38 to 1.44 times higher for men compared to women.

For motorcyclists compared to car drivers, the risk of being in an accident was 1.44 to 1.78 times higher and the risk of being in an injury accident was 2.29 to 3.16 times higher. Singles showed an increased risk of 1.25 to 1.87 times higher for being in an accident and 1.50 to 2.25 times higher risk for being in an injury accident when comparing to person a couple with children.