A Guide for Addressing Collisions Involving Motorcycles

SECTION III - Type of Problem Being Addressed

General Description of the Problem

As motorcycle use increases, providing a safe environment for motorcyclists continues to challenge transportation professionals. Motorcycle ownership has increased dramatically over the last several years and statistical trends have shown a steady increase in motorcycle fatalities. Motorcycles represent approximately 2 percent of all registered vehicles in the United States, but are responsible for only about 0.4 percent of all vehicle miles traveled. In 2006, motorcycles accounted for over 11 percent of all traffic fatalities (FARS, 2006). Exhibit III-1 presents the long-term trend in motorcyclist fatalities, showing a significant increase since 1997.

Exhibit III-2 shows that the annual increase in motorcycle fatalities has been significant not only in numbers, but in percentage change (except for 2002), and as a proportion of all fatalities in the USA. Motorcyclist injuries, however, have not grown in the same fashion. From 1996 to 2006, while fatalities grew 122 percent, injuries grew 60 percent. While the rate of growth for fatalities continues to be steady, that for injuries may be slowing.

When taking into account exposure, however, the increase in fatalities appears to be less pronounced (see Exhibit III-3).

Recent trends show that the number of registered motorcycles in the United States continues to rise along with the number of miles being driven by motorcyclists. Given this trend, unless the issues related to motorcycle safety are addressed directly, fatalities and serious rider injuries stand to increase proportionally.

Single-Vehicle Crashes

Research has shown that as much as 50 percent of all motorcycle crashes are single-vehicle crashes (FARS, 2006). This research has shown that the following factors contribute to the risk of being involved in a fatal single-vehicle motorcycle crash:

• Motorcycle rider over the age of 40
• On a rural road or an undivided road
• High BAC level
• On a curve
• Contacting a fixed object off of the roadway
• At night
• Not wearing an FMVSS 218 compliant helmet
• Not holding a valid or proper license

EXHIBIT III-1
Motorcyclists Killed 1989¡V2006
Source: Shankar, 2004; FARS, 2006

EXHIBIT III-2
Motorcycle Fatality and Injury Trends
Source: Adapted from Shankar, 2004; FARS, 2006

EXHIBIT III-3
Motorcycle Fatality Rates
Source: Adapted from Shankar, 2004; FARS, 2006

While it is often assumed that excessive speed is a factor in the causation of single-vehicle crashes, research has suggested that loss of traction due to the road surface condition is also a contributing factor in crashes (de Rome et al., 2002).

Multiple-Vehicle Crashes

In 2006, 50 percent of all fatal motorcycle crashes were the result of a motorcycle crash with another vehicle (FARS, 2006). Most of these crashes occurred on major roadways (as opposed to freeways and minor roads) and most of them occurred between noon and midnight (NHTSA, 2004). There were also a large number of cases involving alcohol.

In 1981, an in-depth motorcycle crash study conducted in Los Angeles found that 75 percent of all crashes, both fatal and non-fatal, involved a collision with another vehicle, most often at an intersection. Failure to yield the right of way was the most frequently reported cause of a motorcycle-vehicle collision in that study (Hurt et al., 1981). More recent data has suggested that inattention and unsafe speed are also major causes of motorcyclevehicle crashes. There is also recent research that suggests that motorcycle conspicuity is a contributing factor in motorcycle-automobile collisions (Wells et al., 2004).

Specific Attributes of the Problem

Exhibit III-4 illustrates the distribution of helmet use in fatal crashes. Numerous studies have been completed over recent years to quantify the safety effectiveness and value of using a helmet. For example, one study showed that helmeted riders were less likely to have sustained traumatic brain injury across a variety of crash-related factors including crash type, speed limit, highway type and alcohol involvement (Bigelow, 2001). Another study found that riders not wearing helmets were found to be three times more likely to have head injuries requiring either EMS transport or hospitalization or resulting in death than motorcyclists who were helmeted (Finison, 2001).

Speeding is one of the factors that increases the odds of a motorcyclist being at fault in a collision (Kim, 2001). Exhibit III-5 shows that speed is a contributing factor in fatal crashes 37 percent of the time, which is about twice the rate for drivers of passenger cars or light trucks (NHTSA, 2006b).

Alcohol involvement among motorcycle riders is higher than all other vehicle types (passenger cars, SUVs, vans, and pickups [NHTSA, 2005]). The operation of a motorcycle combined with alcohol can lead to deadly consequences for motorcycle riders and passengers. In fact, riding a motorcycle while under the influence of alcohol is a leading cause of fatal crashes involving motorcycles. Exhibit III-6 illustrates the distribution of blood alcohol level in fatal crashes.

Licensing programs are necessary to measure the readiness of riders to ride safely on the road. Many riders, however, avoid the licensing process and ride illegally. In 2006, one in four motorcycle operators (24 percent) involved in fatal crashes was operating the vehicle with an invalid license, as illustrated in Exhibit III-7. This compares with only 13 percent of drivers of passenger vehicles involved in fatal crashes without a valid license (FARS, 2006). Typically, riders who are operating a motorcycle with an invalid license are actually operating a vehicle "out of class," meaning that the rider has an automobile license but the license is not lawfully endorsed for motorcycle operation.

An interesting trend in motorcycle safety is the changing distribution of motorcycle fatalities by age group. Exhibit III-8 presents the age distribution of motorcycle fatalities in 2006. While the exhibit does not demonstrate any trends over recent years, older motorcyclists have become proportionately more involved in fatal crashes. In fact, the number of fatalities in the over-40 age group has been steadily increasing since 1992. This could be due to a combination of the aging of the younger population of users, or it could be due to an increase in new motorcyclists among the older population.

EXHIBIT III-8
Age Distribution of Motorcycle Fatalities in 2006
Source: FARS, 2006