National data suggest that as motorcycle registrations increase, motorcyclists' deaths and injuries increase. Conversely, when registrations decline, fatalities and injuries decline. In Florida, motorcycle registrations increased substantially following repeal of the all-rider helmet law, an outcome similar to that seen in the other States that repealed helmet laws in recent years. It is likely that some of the increases in motorcyclist fatalities were due to increased ridership. However, the analyses show that increases in motorcycle registrations alone do not account for the magnitude of the increases in fatalities.
Nationally, motorcycle vehicle miles of travel (VMT) increased gradually throughout the 1990s, but decreased in 2001 and 2002. The VMT measure, provided by the Federal Highway Administration, is regarded as a good indicator of trends year to year, but cannot be broken down reliably to the individual State level for motorcycles. Nationally between 1998 and 2002, motorcycle registrations increased by approximately 29 percent. In 1998, the average motorcycle traveled 2,645 miles, while in 2002 this figure had declined to 1,909 miles. The extent to which this effect occurs at the individual State level is not knowable from existing data sources.
The effects of Florida's repeal of its all-rider motorcycle helmet use law are similar to those seen in the other States that have repealed such laws in recent years. Based on these findings, it is reasonable to conclude that the following are likely outcomes in a State considering elimination of an all-rider helmet law:
• Helmet use will decline markedly, from virtually full daytime compliance to voluntary use by about 50 percent of riders.
• Helmet use likely will decline among all riders regardless of restrictions remaining in the law (use required by young riders, those without insurance) because of enforceability factors.
• Motorcycle registrations will increase. This, in turn, will contribute to an increase in motorcycle crashes of all degrees of severity.
• Motorcyclist fatalities will increase significantly, typically by 50 to 100 percent comparing the years following the law change with the years immediately before repeal. The fatality rate per registered motorcycle will also increase.
The Florida results also show that with non-fatal injuries, serious injuries increase more than lesser injuries following law repeal. Injured motorcyclists' hospital admissions increased by 40 percent following the law change. Admissions for head-brain-skull injuries increased by more than 80 percent. Total gross treatment costs for these cases more than doubled and the cost per case also increased substantially. Fewer than 25 percent of hospital admitted motorcyclists for head-brain-skull injuries bore treatment costs under $10,000, indicating that the law's medical insurance provision is largely inadequate to cover the costs incurred. Only about two-thirds of admitted motorcyclists have medical insurance.
The Florida law continues to require helmet use by riders under the age of 21. Unfortunately, the data suggest that this provision is not being observed. The number of under age 21 motorcyclists killed in Florida in the two years after the law change nearly tripled compared to the two years before the change. Almost half of the post law change victims were not helmeted compared to about 26 percent before the law change. The number of young motorcyclists involved in crashes of lesser severity increased by about 47 percent comparing the year after the law change with the year before the change. Helmet use by these riders went from more than 70 percent before the law change to about 50 percent after the change.
Motorcycling is a relatively dangerous mode of transportation. Nationally in 2002, there were 32.7 motorcyclists killed per 100 million miles of travel compared with 1.2 occupants of passenger cars killed per 100 million miles of travel. Public and private undertakings that lead to increased motorcycle ridership will inevitably lead to increased deaths and injuries. The policy issue is whether the public sector has the duty and responsibility to require reasonable safety equipment to ameliorate the severity of the crashes that will occur. Those opposed to this position generally argue that their individual freedoms are being diminished and that they have the right to crash and suffer if they so choose. Those who advocate the safety perspective point out that the road system is in the public domain and, therefore, that government has the obligation to set standards for its safe use. Further, they note that the costs of serious motorcycle crashes, especially when head injuries result, are far beyond what most individuals can bear, thus requiring substantial public and private contributions.
Motor vehicle crashes, including motorcycle crashes, rarely are isolated events affecting only the crash victims. For instance, the Center for Disease Control (CDC, 2003) estimates that approximately one-third of adults hospitalized with traumatic brain injury from all causes still need help with daily activities one year after their discharge.
Beyond cost considerations, there are quality of life losses for victims and their families. Additionally, friends, co-workers, and innocent bystanders can all be affected by the crash and its aftermath. While the sample is small, it is interesting to note that among Miami-Dade County motorcyclists injured after the helmet law repeal, only about one-quarter had returned to motorcycling a year after their crashes and, of these, almost all wore helmets when doing so.
Based on the available evidence the increase in motorcycle fatalities that occurred after the Florida motorcycle helmet law was repealed is due in part to the reduced use of helmets. Our analysis shows this is the case despite the pre-existing trend of increasing fatalities, the increase in fatalities associated with increased exposure (measured by registrations), the increase in fatalities that occurred in the first six months of 2000 (before the helmet law repeal became effective), and the likely contribution of a demographic shift in motorcycle ridership.
The effect of the motorcycle helmet law repeal on injuries is somewhat less clear than the situation for fatalities. Two sources of data were available: police motor vehicle crash reports, which show an increase in injuries, but a small decline in injury rates per 10,000 registrations; and hospital discharge data that show large increases in hospital admissions and dramatic increases in admissions for head injuries. The weight of the evidence indicates that the repeal of the helmet law was associated with a slowing of the existing downward trend in injury rates, with an increase in head injuries. The cost data show that the total acute care cost more than doubled. As with fatalities, increased exposure (registrations) cannot account for these changes.