[Ken Kifer's Bike Pages]
ARTICLE: Why I Am Opposed to MHL's
Mandatory helmet laws for bicyclists, although advocated by many physicians, medical researchers, helmet designers, and cyclists, do not promote the public health.

Why do some cyclists and physicians advocate mandatory helmet laws (MHL's)? Why have many non-cyclists become convinced that bicycling is a dangerous activity? Which states and countries have mandatory helmet laws? What are my attitudes towards helmet use and towards discrimination against cyclists based on helmet use? What are the arguments that support mandatory helmet use? Is bicycling dangerous and is the chance of having a serious head injury while bicycling very high? What is the cause of most serious cycling accidents? How many years would the average cyclist ride between accidents, serious head injuries, and head injury deaths? What percentage of the total US head injuries happen to cyclists? Why is the head so likely to be injured in an accident? What other methods of avoiding injury exist besides the wearing of helmets? Can we believe all the testimonials that "a helmet saved my life"? How are helmets tested? Why is this testing inadequate? Why don't manufacturers want safer helmets? What medical research makes the strongest case for the mandatory use of helmets? What statistical evidence is used to back this claim? Why is an 88% reduction in head injury rejected as unbelieveable? What real-world tests have demonstrated that helmets have no effect on injuries? How did Rivara and Thompson get their high results? How can income levels and fear of head injuries influence hospital admissions? What is wrong with legislating behavior that is not harmful to others? What is especially wrong about legislating helmet use? Why did the British Medical Association decide to oppose mandatory helmet laws? Why is bicycling without a helmet good for the health? Why won't some people wear helmets? What are some better solutions than mandatory helmet laws?


Bike Pages Home Page

The Cyclist Lifestyle

Bike Commuting and Transportation

Bicycle Camping and Touring

Cycling Health and Fitness

Bicycling Advocacy

Bicycle Traffic Safety

Basic Skills for Cyclists

Cycling Humor and Tales

Bicycling Surveys and Statistics

Links to Other Cycling Sites

Comments on This Page

Why I Am Opposed to Mandatory Helmet Laws

This discussion replaces another published under the same url. I replaced the earlier statement to deal with more aspects of the issue and to speak a little more emphatically. I have not cited the sources of my evidence for each statement below; however, my sources are all found within the right-hand column.

There is a great controversy going on within both the cycling world and the medical world about bicycle helmets. Some feel that bicycle helmets are extremely effective at preventing injury and death, and many of those feel that helmet use should be mandated by law. Because of statements made about the dangers of cycling in order to encourage helmet use, many non-cyclists have become convinced that cycling is an extremely hazardous activity.

At present about half of the states in the US have mandatory helmet laws for all or part of the state and for all or part of the cycling population. At present, no state requires adults to wear bicycle helmets, but in 16 states, there is a state-wide law requiring at least some children to wear helmets, especially children riding as passengers on bicycles. In addition to the states, cities often require helmets for adults and/or children.

Other countries have considered helmet laws, and Australia, New Zealand, and the Canadian provinces of British Columbia and Nova Scotia have passed mandatory helmet laws for all cyclists (Ontario requires bicycle helmets for children).

It is my own belief, based on experience and evidence, that mandatory helmet laws do not make sense. This does not mean that I think that no one should use helmets; I believe that the choice of whether to use a helmet or not or what kind of helmet to use should be up to the cyclist who will be using it. I think that neither the cyclist who wears a helmet nor the cyclist who fails to wear a helmet is foolish. However, I think that any cyclist who discriminates against another cyclist on the basis of helmet use is both a fool and a bigot.

The Arguments in Favor of Mandatory Helmet Use

The argument that helmets should be mandatory can be broken into several smaller arguments which I will first summarize and then contradict at length:

1) Bicycling accidents are frequent and unavoidable, and head injuries and death are likely to result from these accidents.

2) Many cyclists have attested that a helmet saved their lives and even have battered or broken helmets to prove it.

3) Scientific evaluations have been made of helmets which ensure that they will protect the head against almost all injures.

4) Researchers have determined that up to 88% of head injuries or deaths could be avoided by wearing a helmet. A drop in the number of cyclists killed each year is further proof that bicycle helmets work.

5) Any protection is better than none, there is no handicap involved in wearing a helmet, and no advantage comes from not wearing one. Statistics show that when bike riders are given a free choice of whether to wear helmets or not that most of them don't.

Putting these arguments together, it's easy to see why many who are convinced of the effectiveness of helmets are also convinced that mandatory helmet laws are the right decision to make. Requiring all bike riders to wear helmets seems as natural as requiring all motorists to use safety belts.

Nonetheless, I don't find any of these arguments convincing, and I have some additional reasons to feel that mandatory helmet laws are not a good idea.

The Risk of Head Injury and Death While Cycling

I frequently encounter the argument that bicycle injuries are frequent and unavoidable and that head injuries make up the bulk of these. Indeed, head injuries have become associated with cycling due to the various statements made.

These ideas do not square with my experience as a cyclist. Over 100,000 miles of cycling, much on highways, has resulted in my having just six falls during my life, none of them involving head injury and none requiring a trip to the doctor. In all six cases, my arms protected my head from striking the ground. I avoid accidents by being careful and obeying the traffic laws, which is much more effective than ignoring traffic and hoping the helmet will be sufficient, as I have seen others do. [NOTE: On Feb. 15, 2002, I suffered my seventh fall, which did send me to the hospital. I did not injure my head.]

Nor do these ideas square with available data on bicycling accidents and injuries. Most serious cycling injuries are the result of not obeying the traffic laws, and most could have been easily avoided by the cyclist; for instance, according to Riley Geary, the primary cause of adult deaths while cycling is riding at night, yet few have the required lights on their bikes.

For evidence that cycling is a fairly safe activity which does not result in an undue number of head injuries, I will use John Hopkins as the source of my data, a source funded by Snell which promotes the use of helmets. According to John Hopkins, there are 300 injuries per million bicycle trips and 1.8 billion cycling trips per year. This works out to about 540,000 injuries per year, but even if we assume that each cyclist has an cycling trip every day, that is an average of over nine years between injuries for each cyclist. The number of cycling head injuries requiring hospitalization (from the same source) is 7,700 per year or about 1.5% of the total cycling injuries (about 630 years between head injuries of this severity), and John Hopkins estimates the number of deaths due to head injuries by cycling is about 70 to 80% of the total cycling deaths or say 560 to 650 head injury deaths per year (about three million trips per head injury death, or 8,427 years between these fatalities, assuming a trip every day). From the Caregiver web site, I learned that, in the US each year, there are a total of 500,000 to 750,000 hospitalizations due to head injuries and 75,000 to 100,000 head injury deaths. Thus, bicycle head injuries constitute only about from 1.02% to 1.54% of the US total serious head injuries and from .56% to .87% of the head injury deaths. The largest group of head injuries, by the way, are among motorists. Therefore, bicycling is not dangerous, nor is it a leading cause of head injury.

The idea that there are so many head injuries each year in the US may seem disturbing, but remember that the heart and the brain are the two most vulnerable parts of the body, and the heart is much better protected than the brain. Therefore, in the case of any type of severe accident, a head injury of some sort is likely to be involved. Cycling is no more dangerous per hour than taking a walk or riding in a car (and most deaths in those cases result from head injury) and much less dangerous than other common activities. Should we wear a helmet everywhere we go?

I admit that some cyclists are at much higher risk of having accidents than the average. Many of those at high risk are those who are not obeying the traffic laws. In this case, the most important remedy is not a helmet but instruction in the traffic laws. Some of these are riding at night without lights, and these cyclists should purchase some good lights before thinking about purchasing helmets. On the other hand, other cyclists engage in deliberately risky behavior such as high-speed off-road downhill cycling, and a few cyclists have serious bike handling and balancing difficulties; for both of these groups of cyclists, the best helmet money can buy is highly recommended. However, there is no reason to make all cyclists wear a helmet because some have a greater than normal risk.

Testimonials that "A Helmet Saved My Life"

Defending mandatory helmet use are testimonials by numerous cyclists that their helmets saved their lives in falls, often accompanied with such evidence as a smashed or broken helmet. In some cases, the cyclist suffered severe head injuries in spite of the helmet; therefore, the conviction is even stronger that the helmet must have saved the cyclist from death.

However, the evidence of dented and broken helmets is proof of nothing. After all, they are made of light foam with perhaps a thin coat of plastic. It seems that the helmet must have reduced the impact somewhat, but it's impossible to say how much, as many cyclists do land on their heads without wearing helmets and yet still walk away from the accident. In some cases, the size of the helmet may have contributed to its contacting the ground. In the case of those seriously injured while wearing helmets, one might equally argue that the helmet should have been stronger.

I'm glad that these cyclists were not more severely injuried and, if the helmet helped, I am even more glad, and I do not wish to discourage people from wearing that additional protection, but I also do not find such testimonials justify mandatory helmet laws.

Helmet Design and Testing

Going beyond testimonials, we find that modern helmet design is based on scientific tests and measurements, and thus seems to be beyond criticism. However, when the helmet standards to which all helmets must adhere and the methods of testing the helmets are studied, it seems that there are grave weaknesses both in the standards and in the procedures.

First, the standards are based on a 300 gravity deceleration of the head, which is about the maximum impact the brain can withstand without serious injury. Even Randy Swarts of the Bicycle Helmet Safety Institute thinks this standard is too low. The paradoxical problem that bicycle helmet designers face is that if they design a helmet with adequate protection, few cyclists will be willing to wear it.

But this is just the beginning of the problem with helmet standards. The method of testing a helmet is to place an eleven-pound weight inside, to drop it a fixed distance on various surfaces, and to measure the deceleration. At present, bicycle helmets are dropped a distance of six and a half feet onto flat surfaces and distances of less than four feet onto rounded or irregular surfaces, and if the resulting force of impact is less than 300 gravities, the helmet is considered to have passed the test. But these are hardly adequate tests. In most tests, the helmet is dropped or struck on or near the top, where it is strongest, yet the side or front of the head is much more likely to be struck either in a fall or a collision. In addition, in the event of even a simple fall, there's not just the weight of the cyclist's head to consider but also the weight of the whole body as well. In the event of a collision with a motor vehicle, the cyclist will impact with many times the force of a simple four to six foot fall.

Thus the helmets currently sold are designed to protect against minimum falls under ideal conditions for the helmets, not for real falls by human beings, and they are certainly not designed to protect against the cyclist being struck by a fast-moving motor vehicle, the cause of over 90% of all cyclist deaths. Some sources suggest that helmets or some helmets may actually increase head injury under these conditions by increasing the rotational forces against the head.

Recently, I looked at the fact sheet packed with a bike helmet, and it included clear warnings of the limitations of the helmet, including the rotation problem, evidently to reduce the liability of the manufacturer.

Research Results on Helmet Use

Much stronger evidence supporting mandatory helmet laws seems to come from the study made by Thompson, Rivara, and Thompson, using doctor and hospital records, which demonstrates a reduction of 85 to 88% in head injury or death by helmet users. This study is cited more than any other as proof that helmets work. A decline in the number of cycling deaths nationwide is seen as further proof that bicycle helmets work.

The Thompson, Rivara, and Thompson figures seem strange in view of what we know about helmets. This high effectiveness contrasts with what we know about the weak helmet standards and the inadequacy of any helmet to protect a cyclist struck by a motor vehicle. After all, a combination of air bags and seat belts in passenger automobiles is judged to be effective just 50% of the time. Yet these authors maintain, in a second study, that they found less than 88% effectiveness in that study solely due to the lack of controls, that helmets are equally effective in collisions with motor vehicles, that all helmets offer similar protection, and that, "despite the overwhelming protectiveness of helmets, [only] a few helmeted cyclists did suffer head injuries" -- often due to wearing them incorrectly. I find this belief in the effectiveness of helmets to be unreal.

Due to such strong support for helmet use, mandatory helmet laws have been passed, but whole population studies of the results have failed to find the benefit that had been claimed. Australia passed mandatory, nationwide helmet laws for all cyclists and, as a result, 80% of all cyclists in Australia began wearing helmets. Helmet proponents soon pointed to a decline in the number of cycling injuries and deaths in Australian as proof that helmet laws work. However, when other researchers plotted cycling fatalities against pedestrian fatalities during the same period of time, they found that the same reduction in injuries and death occurred with both, even though the pedestrians never began wearing helmets. Also, when they plotted head injuries against other injuries among cyclists, both types of injuries declined at the same rate. Nor could they find any change in the decline connected to the introduction of mandatory helmet laws. Therefore, the decline in injuries and deaths was due to other factors, not the use of helmets. Since then, an examination of US and Canadian accidents in areas with mandatory helmet laws reveals similar results. Thus there is no real world evidence that helmets work.

Then how did Thompson, Rivera, and Thompson get their 88% effectiveness result? Their work was conducted in hospitals and through an HMO, and they compared the injury rate and severity of injury of cyclists coming to be treated. Those wearing helmets had fewer head injuries and less severe head injuries than those who did not wear helmets.

However, there is a grave weakness in this methodology. Rather than studying the whole population of cyclists, this study looks only at those who chose to get treated. Cyclists who are paranoid about head injury are much more likely to wear helmets and are much more likely to show up at the hospital or doctor's office with a minor bump. Cyclists who are not afraid of a bump on the head are much less likely to wear helmets and much less likely to show up with a minor injury.

Thus this study simply demonstrates that cyclists who are worried about head injuries are eight times more likely to visit the hospital or doctor after a bicycle accident than those who are not. As evidence that this is exactly what did happen, it has been discovered that the percentage of helmet-wearing cyclists in the study was seven times the percentage of helmet-wearing cyclists in the same community. Dorothy Robinson's look at the data (unpublished) revealed that the helmet-wearers had 75% fewer non-head injuries than the other cyclists; yet helmets can't protect against these other injuries. Finally, it has been determined that the helmet-wearers, as a group, had higher incomes, and thus were more likely to have medical insurance. A cyclist with a low income and very likely no health insurance is unlikely to seek help for a bang on the head.

Rather than revealing that helmets are 88% effective, this study reveals that medical journals can be guilty of publishing badly flawed and biased research. There are other attempts to show the effectiveness of helmets; these studies show from 65% benefit (the second Thompson, Rivara, and Thompson study) down to none. It is then highly misleading, under these circumstances, then, to say that helmets are 88% effective, yet this is the statistic that is most commonly used. Intuitively, it would seem that helmets must have some benefit in the real world, but considering that over 90% of cycling death result from being struck by automobiles traveling at high speeds rather than from minor spills at low speeds, it's easy to see why they do not.

Legislating Behavior

In spite of all this, there are those who argue that any protection is better than none, that there is no reason for not wearing a helmet, and no advantage comes from not wearing one. While seemingly a weak argument, this is perhaps the strongest, and it is often employed after all other arguments have failed.

Many, perhaps most, cyclists adapt to helmets very well, feel comfortable wearing them, have no problem paying for them, and feel naked without them. Therefore, they see no problem in insisting that everyone else wear a helmet.

I certainly have no problem with people doing what makes them feel comfortable as long as it's not dangerous to anyone else. But I really do have a problem with them forcing their choices on others. Many prefer Windows to other operating systems, so why not make the use of Windows mandatory? I enjoy eating broccoli, and it is considered one of the healthiest foods; why not make the weekly eating of broccoli mandatory? Overweight and sedentary people have greater health risks and costs; why not force them to exercise? Why not outlaw smoking and drinking, confiscate all fire arms, require everyone to ride bicycles to work, and so on? It's beyond question that we have to forbid actions that are dangerous to others, but should we pass laws to protect ourselves from ourselves?

Some feel that they should not have to help pay the insurance cost of those injuried while bicycling without helmets. Then, should I have to help pay the health costs for those who fail to bicycle 60 miles a week and thus have coronary heart disease, strokes, type II diabetes, and other sedentary ailments? Should I have to help pay the health costs for those who injured their heads in car wrecks, in falls, or through firearm accidents who were not wearing helmets? Where do we draw the line?

Recognizing the conflict created by mandating helmet use for adults, some have suggested that mandatory helmet laws be applied to children only, evidently based on the belief that children, unlike adults, should not be allowed free choice. I'm afraid I find this notion even more disturbing. Children become adults only by learning to exercise their own judgments. Forcing them to obey unnecessary laws does not make better adults out of them. And forcing them to wear helmets will discourage them from riding bikes as children, will keep them from acquiring the bike-handling skills they will need as adults, and will firmly place them on the path to a sedentary lifestyle. While I see no problem with encouraging children to wear helmets (rather than forcing them), the best solution to childhood cycling injuries and fatalities lies in teaching children the traffic code, as I was taught as a child and as I passed on to my friends, which prevented us from having collisions with each other and with cars.

There is indeed some harm to those who don't wish to wear helmets for one reason or another when mandatory helmet laws exist -- they quit cycling or bicycle less often. Australian studies show a decline in cycling after mandatory helmet laws were introduced. The British Medical Association estimates that the health benefits of cycling outweigh the dangers by twenty to one and, because of the danger of cyclists not riding their bikes or riding their bikes less often, the BMA has therefore declared itself opposed to mandatory helmet laws.

There are several reasons for a decline in cycling due to mandatory helmet laws. First, those with lower incomes may not be able to afford the cost (whether helmets are cost-effective is in itself a debatable issue). Some have suggested free or low-cost helmets as a solution, but those with little income are the least likely to seek these solutions, in fact, may be too proud to take advantage of them. Second, many cyclists find helmets uncomfortable due to design. The most common complaint is that the helmets are too hot, as the body radiates most of its heat through the head. This has led to the many holes in the helmet which weaken it. I don't wear a helmet because I find the hard foam pads extremely uncomfortable, and I wonder why the manufacturers don't employ a simple head band instead, as is found in construction hard hats, which are much more comfortable. Other problems concern style, the effect of the helmet on a hairdo, and the problem of carrying the helmet around to prevent theft. For some of these reasons, there are many cyclists who wear a helmet part of the time (say when going on a mountain-bike ride) and not at other times (say while climbing a hill or while cycling to work). Harping about the dangers of cycling in order to encourage helmet use also tends to reduce cycling. Whatever the reason, people who have problems with helmets are going to bicycle less often or even quit bicycling, and that is going to endanger their health more than the risks they would run by bicycling without a helmet.


Thus, after reviewing the evidence and thinking about the consequences, I have come to the conclusion that mandatory helmet laws are not only unnecessary but harmful. Even if helmets were 100% effective, their mandatory use for the safer forms of cycling would be unjustified, considering the fact that many would quit riding or ride less and the fact that the health benefits greatly outweigh the risks.

My saying this does not indicate that I am opposed to helmet use. In fact, the one reason for my not writing this earlier was that I did not and do not wish to discourage cyclists from wearing helmets if they want to. After all, some people would not feel comfortable on a bike without a helmet. If not allowed to wear helmets, they would bicycle less or not bicycle at all, which would be bad for their health. I also feel that those cyclists involved in high risk activities should be encouraged to wear helmets and that they should be able to purchase better helmets than those currently available.

I think that, instead of pushing for helmet laws or using other methods to force cyclists to wear helmets (such as excluding bare-headed cyclists from club membership or rides), those supporting helmet use and those manufacturing helmets should work to improve helmet design, variety, and attractiveness. I also feel that they should quit making exaggerated claims about the danger of cycling and the safety of head gear. Rather than saying that helmets are 88% effective, I think it would be sufficient to say that a helmet would provide additional protection for the head.

I acknowledge the fact that my discomfort while wearing a helmet and my many years of bicycling without head injury has biased my conclusions; however, I feel I am certainly less biased than those who look at cycling through the wrong end of the telescope.


Is Cycling Dangerous?  Looks in greater detail at the risks involved in cycling and comes to the conclusion that cycling is much less risky than sedentary behavior.

How to Ride in Traffic  Shows how one can safely bicycle from one place to another.

How to Avoid Cycling Accidents  Shows that most collisions with motor vehicles can be easily be avoided by being more careful. Evidence comes from a bicycle crash study and from personal experiences.

Looking Through the Wrong End of the Telescope  Looks at the sociological and psychological reasons why cyclists and physicians can come to different conclusions on the helmet issue.


Not on the internet is the Thompson, Rivara, and Thompson study on the effectiveness of bicycle helmets, published in the New England Journal of Medicine in 1989. However, a more recent study by them (Circumstances and Severity of Bicycle Injuries) is available on the Snell web site.

The British Medical Association  speaks out against mandatory helmet laws. The responses are very interesting as well.

The Bicycle Helmet Safety Institute  Randy Swarts' website, which strongly argues in favor of helmets, is a rich source of information. On the site, I found the John Hopkins statistics on bicycle accidents, information about helmet testing, and information about which states have required helmet laws.

Fact Sheet: Selected Head Injury Statistics  My source of information about total US head injuries. Note: this source also claims that helmets are 88% effective and that 12% of US transportational head injuries are from cycling. This second fact might be true when looking at minor head injuries, but it is not true for head injuries resulting in hospitalization or death.

Is There Any Reliable Evidence That Australian Helmet Legislation Works?  by Bruce Robinson. Shows trends before and after legislation introduced, including pedestrian/cyclist comparisons that establish that the helmet laws had no effect.

Cycle Helmet Laws - Facts, Figures and Consequences by Dorothy L Robinson. Excellent graphs and clear demonstrations, including head injury vs. other injury comparisons, that the Australian helmet laws had no beneficial effects in spite of 80% helmet use.

An Economic Evaluation of the Mandatory Bicycle Helmet Legislation in Western Australia  Bicycle helmet law education, enforcement, and administration cost $1,367,000 and bike helmets cost over $20,000,000 in Western Australia. While the number of helmet injuries prevented is more debatable, the cost per injury avoided was $70,000 or $151,000, using two methods of analysis to determine how many helmet injuries were avoided. This study acknowledges but does not try to calculate the health benefit costs created by discouraging cycling.

The Bicycle Helmet FAQ  A thorough discussion of the myths about bicycle helmets by Avery Burdett; discusses some of my points in greater detail and includes other arguments. On the same site is Thomas H. Kunich's report and graphs on the Latest CPSC Helmet Standard and US Fatality Trends and Avery Burdett's Cyclist Fatalities in Canada 1975 to 1997 both of which show little difference between cyclist and pedestrian fatalities (helmet use, however, was much lower than in Australia). The Ontario Coalition for Better Cycling website has excellent information on Canadian helmet laws and bicycling conditions.

Improving Bicycle Safety without making helmet-use compulsory by The European Cyclists Federation. A very readable and to-the-point discussion with facts drawn from Europe.

The Effectiveness of Cycle Helmets: An Investigative Paper by John Franklin. A very objective look at the controversy by a British bicycling expert and author.

Here's to No. 75616   by John S. Allen. A personal testimonial to the effect that helmets work, by a US cycling expert and author.

A Cyclists Rights Action Group (CRAG) CRAG was organized to fight mandatory helmet laws in Australia. Information and links about helmets and safety research plus links to other sites.

Compulsory Helmet Laws Endanger Public Health  A site from Western Australia by Chris Gillham opposed to mandatory helmet laws.

The Bicycle Helmet Legislation, Curse or Cure?  Nigel Perry points out the paradoxes of the helmet laws in New Zealand and suggests some solutions.

The Helmet Wars  De Clarke has been working hard to make her bicycling site very comprehensive on the helmet and safety issues. A great deal of information, much of it hard to find or not found elsewhere.

Faulty FARS Bike Helmet Data by Riley Geary. Although you may have heard that few cyclists are dying with helmets on, these "statistics" are coming from faulty data gathering and reporting. In particular, "no information" is often mistakenly reported as "no helmet."

Comments | SECTIONS: | The New World | Writing | Thoreau | Home | Bike Pages |
DIRECTORIES: | Lifestyle | Commuting | Touring | Health | Advocacy | Traffic | Skills | Humor |Survey | Links |
ADVOCACY ARTICLES: | Newslist | Website | Auto Costs | Right | Far Right? | Pay? | Be Paid? | Carbon | Auto Depend | Warming | Helmets | Issues |Bikeways |
http://www.kenkifer.com/bikepages/advocacy/mhls.htm | Copyright © 2000 Ken Kifer | Revised Friday, January 28, 2000