IV. EFFECTS OF THE LAW CHANGE IN KENTUCKY
Kentucky first enacted a motorcycle helmet law applicable to all riders in 1968. It was this law which was amended effective July 1998 to require helmet use only by:
The originally amended law also required helmet use by those who did not have at least $10,000 of medical insurance coverage. Owners of registered motorcycles were to provide proof of insurance to their county clerks who would issue a helmet use exemption sticker to be displayed on the insured's motorcycle. Anecdotal information suggests that there may have been questions about the insurance provision; for example, whether helmets were required by passengers and by out-of state motorcyclists who had insurance. The medical provision was repealed effective July 2000.
Motorcycle helmet use is observed annually as a part of the state's safety belt usage survey. Agent (2000) reports that,
"surveys taken during the mandatory [motorcycle helmet] usage period had found a usage rate of over 95 percent. Data were taken in 1998 both before and after the effective date of the repeal. Prior to July 15, 1998 only 10 of 240 observed motorcyclists were not wearing a helmet, giving a usage rate of 96 percent. After this date, 29 of 148 motorcyclists were observed not wearing a helmet giving a usage rate of 76 percent. In 1999, 164 of 452 motorcyclists were observed not wearing a helmet with a weighted usage rate of 65 percent. The weighted rate for 2000 was 70 percent with a sample size of 427".
The 2001 survey recorded a 56 percent helmet use rate. (Agent, 2002). Table 2 summarizes these figures.
Table 3 lists Kentucky's motorcyclist fatality experience around the time of the helmet law change. The table shows that in the two years immediately prior to the law change (1996 and 1997), there were 22 and 24 fatal crashes, respectively, involving motorcyclist victims and there were 24 fatalities each year. In the two years immediately after the law change (1999 and 2000), there were 38 and 35 fatal crashes involving 40 and 36 motorcyclist fatalities. That is, annual motorcyclist fatal crashes and fatalities increased by more than 50 percent following the law change.
Motor vehicle injury crash data published by the state (Kentucky Transportation Center, 1996-2000) for motorcycle involvements in injury crashes and injuries are show in Table 4. In 1996-1997, there was an average of 573 injury crashes involving motorcycles, while in 1999-2000, there was an average of 785 injury crashes; a 37 percent increase. The average number of injuries involving motorcycles increased by 34 percent, from 703 in 1996-1997 to 942 in 1999-2000.
In crashes where motorcyclist injury severity and helmet use were known, helmet use declined from 75% of those injured in 1996 to 52 percent in 2000, while the number of injured riders increased (see Table 5).
Table 5. Kentucky Helmet Use and Injuries 1996-2000(2)
Similarly, helmet use among riders sustaining serious (A) injuries declined from 71 percent to 50 percent while the number of these injuries also increased. Table 5 also shows that the number of riders sustaining head and/or face injuries increased substantially following the repeal of the universal helmet law. The number of helmeted riders sustaining head/face injuries changed little over the years 1996-2000, while the number of unhelmeted cases of head injury more than doubled.
Table 6 shows the number of motorcycles registered in Kentucky during the 1996-2000 period, along with motorcyclist fatality and injury rates per registered vehicle. Registration data are from the FHWA.
Motorcycle registrations increased more or less steadily each year during the period. Motorcyclists killed per 10,000 registered motorcycles increased from less than 7 under the universal helmet law to more than 8 following repeal. The rate of persons injured in motorcycle crashes also increased following the law's repeal.
The increase in number of motorcyclists killed and injured per 10,000 registered motorcycles appears to be due, in part, to the motorcycle helmet law repeal. National data suggest that registrations are higher in States without mandatory helmet laws. Repealing mandatory helmet use laws may result in more registrations. Other national data suggest a trend towards larger bikes and older riders. Thus, the increase in registrations experienced by Kentucky and Louisiana after repeal of their helmet use laws may have also resulted in an increase in older/less experienced riders on larger bikes who are at greater risk of crash involvement. Unfortunately, insufficient data were available to determine the extent to which the increased fatality and injury rates were due to reduced helmet use, to increased exposure, or more riding by riders at higher risk of crash involvement.