CONTRACTOR CONTRACT NUMBER
Preusser Research Group, Inc. DTNH22-99-D-25099
Evaluation of Repeal of Motorcycle Helmet Laws in Kentucky and Louisiana October 2002
R.G. Ulmer and D.F. Preusser
At the end of 2001, 20 states and the District of Columbia had laws requiring all motorcycle riders to wear helmets; 27 states had laws requiring helmet use only by riders under a certain age (usually 18); 3 states had no laws regarding motorcycle helmet use. Mandatory helmet use laws first came into being following the issuance of highway safety program standards in 1967. From the outset, the enactment of helmet laws has been a contentious issue in many states as public policy makers have debated the balance between personal freedoms and the societal costs of crashes. Those opposed to mandatory helmet laws generally argue that their individual rights are or will be infringed upon and that helmet use should be left to the choice of individual riders. Those who advocate for helmet laws note that helmets are effective in reducing injury severity and that society bears a significant portion of motorcycle crash costs, thereby establishing a public interest in requiring the use of reasonable safety equipment. Over the years, states have variously enacted, repealed, and reenacted universal, or all-rider, motorcycle helmet laws.
In 1998, Kentucky repealed its universal motorcycle helmet law and, in 1999, Louisiana repealed its law. These actions follow similar steps taken by Arkansas and Texas in 1997. More recently, Florida repealed its universal helmet law. This report examines data from Kentucky and Louisiana to assess the effects of their helmet law changes on helmet use and motorcyclist fatalities and injuries.
Kentucky first enacted a motorcycle helmet law applicable to all riders in 1968. It was this law that 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. The medical provision was repealed effective July 2000.
Louisiana first adopted a motorcycle helmet law applicable to all riders in 1968. That law was amended in 1976 to require helmet use only by riders under the age of 18. Then, in 1982 the state reenacted a universal helmet law. It was this latter law that was amended effective August 1999 to require helmet use only by:
Observed Helmet Use
Based on statewide observational surveys, motorcycle helmet use decreased substantially following repeal of the universal helmet laws. In Kentucky, in the last full year under the law (1997), observed helmet use was 96 percent. In the first year following repeal (1999), helmet use was measured at 65 percent. It stood at 70 percent in 2000 and at 56 percent in 2001. In Louisiana, full compliance was recorded in the last full year under the universal helmet law (1998). In 2000 and 2001, helmet use was measured at 52 percent.
These results are similar to what occurred in Arkansas and Texas. Both of these states recorded 97 percent helmet use in the last full year of their laws. Use dropped to 52 percent in Arkansas and to 66 percent in Texas following their universal law repeals.
Fatal Crashes and Fatalities
The number of crashes in which a motorcyclist was killed and the numbers of riders killed increased in both Kentucky and Louisiana following repeal of their universal helmet laws. In Kentucky, in the two years prior to repeal, an average of 23 fatal crashes claimed 24 motorcyclists. In the two full years following repeal, there were an average of 36 fatal crashes and 38 motorcyclists killed.
In Louisiana, in the two years prior to repeal, an average of 26 fatal crashes and fatalities took place. In the two full years following repeal, there were an average of 54 fatal crashes and 55 motorcyclists killed.
As shown in the following table, motorcycle fatal crashes and motorcyclist fatalities also increased in Arkansas and Texas following repeals of their universal helmet laws, although the effect was smaller in Arkansas than has been seen elsewhere.
Comparing the two-year averages of motorcyclist fatalities after the law changes with the two year averages before the law changes shows:
Kentucky + 58% Arkansas +29%
Louisiana +108% Texas +37%
It should be noted that during this same time frame motorcycle fatalities in the U.S. also increased by 50.3%. Motorcycle registrations increased from 1996 to 2000 by 12% and motorcycle miles traveled increased by 5.6% (million VMT). Thus, it is likely that some of the increase in fatalities seen in these States was due to these national trends (increased exposure).
Kentucky motor vehicle injury crash data for motorcycle involvements in injury crashes and injuries show that in the two full years prior to the helmet law repeal (1996-1997), there was an average of 573 injury crashes involving motorcycles while in the two post repeal years(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.
Louisiana motorcycle injury crashes and motorcyclist injuries show that in the last two full years of the universal helmet law (1997-1998), an average of 687 injury crashes took place resulting in 741 motorcyclist injuries. In 2000, injury crashes and injuries increased by more than 40 percent, to 977 and 1,011 respectively.
Data from Arkansas and Texas regarding motorcyclist injuries show that in Arkansas, the number of riders injured increased from 444 in the year before the state's helmet law repeal to 551 in the year after, a 24 percent increase. In Texas, injuries rose from 3,279 to 3,356, a marginal increase of 2 percent.
Arkansas data are EMS cases and exclude Little Rock.
Fatality and Injury Rates
In Kentucky, motorcyclists killed per 10,000 registered motorcycles averaged 6.4 in the two years just before the helmet law repeal and averaged 8.8 in the two years following its repeal, an increase of +37.5 percent. Persons injured per 10,000 registered motorcycles averaged 187 in the preceding two years and averaged 219 in the two years following its repeal, an increase of +17 percent.
In Louisiana, the fatality rate averaged 4.5 in the two years prior to helmet law repeal and rose to 7.9 in the year following, an increase of +75 percent. The injury rate averaged 126 persons in the two years before the helmet law repeal and increased to 152 persons in the year following repeal of the universal motorcycle helmet law, an increase of +20.6 percent.
Nationally, motorcyclists killed per 10,000 registered motorcycles increased 18% and injuries declined by 2.9% from 1997 to 2001. Thus, the increases in fatalities in Kentucky and Louisiana were more than twice the national average increase and the increase in injuries even greater.
The next table shows that the fatality rate in Arkansas did not change appreciably from before to after the repeal of the state's universal motorcycle helmet laws. In the two years before the law's repeal, the rate averaged 11.3 and it averaged 11.4 in the two years after repeal. In Texas, motorcyclists killed per
10,000 registered motorcycles averaged 8.4 in the two years before helmet law repeal and 10.0 in the two years after repeal.
Limitations of Study
Data collected at the national level show that both vehicle miles traveled (VMT) and registrations have been increasing for motorcycles in recent years. Motorcycle fatalities have also been increasing since 1997. National fatality rates per 10,000 registered motorcycles and per VMT have increased by 18% and 59% over this time period. The increase in motorcycle fatalities and injuries in recent years, may be due to the fact that there are more motorcycles on the road, traveling more miles, thus increasing their exposure to harmful events. The VMT measure, provided by the Federal Highway Administration, is a good indicator of trends from year to year, but cannot be broken down reliably to the individual state level for motorcycles. This study reports motorcycle fatalities by VMT, for the nation as a whole, but not for either Kentucky or Louisiana.
To calculate the effect of fatalities by the number of riders, annual motorcycle registration data from Kentucky and Louisiana were used to calculate fatality and injury rates. Registrations increased by 20% in both States. The fatality rate by vehicle registrations increased after the repeal of each state's universal motorcycle helmet law by much more than the number of registrations or the national rate. The injury rate by vehicle registrations increased at approximately the same rate as did the registrations.
The 1998 universal helmet law repeal in Kentucky and the 1999 repeal in Louisiana produced effects similar to each other. Observed helmet use dropped from nearly full compliance under the law to the 50 percent range without the law. Motorcyclist fatalities increased in the near term by sizeable amounts-by over 50 percent in Kentucky and over 100 percent in Louisiana. Injuries also increased substantially in both states. The rates of fatalities per registered motorcycle increased in both states following the helmet law repeals, +37 percent and +75 percent.
The experience in Kentucky and Louisiana is also similar to what occurred in Arkansas and Texas, two other states that have repealed universal laws in recent years (1997), leaving little doubt that such repeals have demonstrable negative safety consequences. The weight of the evidence is that helmets reduce injury severity, that repeal of helmet laws decreases helmet use, and that states that repeal universal helmet laws experience increased motorcyclist fatalities and injuries.