Seat belt legislation
is a law or laws put in place to enforce or require the wearing of seat belts
while driving, or a passenger in, a vehicle
. Most western countries have compulsory seat belt laws. In some areas, mainly in the United States
, these laws are controversial.
Various experiments using both crash test dummies and actual human cadavers have indicated that wearing seat belts should lead to reduced risk of death and injury in certain types of car crash. In addition, hospital based studies of crash accident victims have also indicated that wearing seat belts resulted in significantly reduced risk of death and injury in certain types of car crash. Based on this type of study, predictions such as 45% reductions in fatal injury and 50% reductions in moderate-to-critical injury have been made. As a result of such predictions the use of seat belts by vehicle occupants has been made compulsory in many countries starting with Australia
in the early 1970s. However, such simplistic predictions have never gained unanimous acceptance among safety experts.
Studies that have shown adverse effects of seat belt legislation
In 1981 Professor John Adams of University College, London published a study of traffic accident trends in 18 different countries. The results appeared to show that countries with compulsory seat belt laws actually had poorer accident records than countries without such laws. Indeed, there are several cases such as Sweden, Ireland and New Zealand where car seat belt laws were accompanied by clear increases in deaths among car occupants. At the time this report was published the UK was considering a seat belt law and in response the UK Department of Transport commissioned a study on the effects of seat belt laws in Sweden, West Germany, Denmark, Spain, Belgium
, Finland, the Netherlands and Norway. The study, "the Isles report"
used the United Kingdom and Italy as controls for non-seat belt countries. The Isles report looked at casualty trends for both those inside, and outside, cars. The authors predicted that, based on the experiences of the eight countries studied, a UK seat belt law would be followed by a 2.3% increase in fatalities among car occupants.
From the very beginning in Australia, and subsequently New Zealand, there had been indications that seat belt laws might produce increases in deaths and injury among those outside cars such as motorcyclists, cyclists and pedestrians. The author of the Isles report was alarmed to find that in Europe the predominant effect of seat belt legislation was of increased numbers of injuries to non-car users. The author predicted, that in the UK, deaths to other road users would climb by 150 per year in the event of compulsory seat belt wearing legislation. In terms of injuries to other road users the prediction was for a 11% increase in pedestrian injuries with injuries to other road users climbing by 12 to 13% (numerically 7,000 and 36,000 respectively). The UK authorities suppressed the report (it was later leaked and its findings are now widely available) and the seat belt law was imposed anyway. In the event, the UK's seat belt law was accompanied by actual increases in deaths to pedestrians of 135 per year and of deaths to cyclists of 40 per year (this increase in deaths among these road users represented a 75 year high). A subsequent study of 19,000 cyclist and 72,000 pedestrian casualties seen at the time suggests that seat belt wearing drivers were 11-13% more likely to injure pedestrians and 7-8% more likely to injure cyclists. No clear benefit has been shown for car-occupants as a result of the introduction of the UK seat belt law.
Why does seat belt legislation have this effect?
There are two main theories, the Risk compensation and Risk homeostasis hypotheses. These both argue that car drivers adjust their driving behaviour in response to an increased sense of personal safety. A related theory proposes that during near-miss events the actual physical restraint experienced by seat belt wearers leads to a reduced sense of threat to life. A reduced sense of threat may then lead to the adoption of a more dangerous driving style. Other researchers have attempted to explain the failure of seat belt laws by appealing to the “selective recruitment” hypothesis. This argues that seat belt laws haven't had the expected results for vehicle occupants because those drivers who take the most risks are also the least likely to use seat belts. Unfortunately, the selective recruitment hypothesis does not explain why deaths have been observed to increase following seat belt laws.
The controversy in the US
Recently there has been a push for seat belt laws in the United States
. As elsewhere, this has resulted in controversy. In the US, these disputes centre mainly on the effects for car occupants (e.g., the possibility that seat belt use can cause internal, neck and spinal injuries as it leaves the head free to move inertially while the rest of the body is restrained), and may trap an occupant in a vehicle. Many US opponents also object on the grounds that seat belt laws infringe on their civil liberties
A serious moral dilemma
For decades many US towns and cities have followed policies that have resulted in the effective elimination of walking and cycling as significant forms of transport. It is arguable that concerns regarding seat belt laws and greater endangerment of these road users do not apply in the United States. However, in many developing countries non-car occupants such as pedestrians, cyclists, rickshaw operators and moped users represent the majority of road users. These countries rarely have the resources to physically separate such road users from car traffic. Accordingly, in many such countries non-car occupants also represent the majority of road fatalities. Such countries face a serious moral dilemma about importing "Western", "car-occupant centered", models and theories of road safety such as compulsory seat belt legislation.
Links to sites/studies skeptical/critical of seat belt legislation
Links to sites/studies that endorse seat belts
References and Further Reading
- John Adams, 1995, Risk, Routledge, ISBN 1857280687 — Authoritative reference on risk compensation theory.
- Wilde G.S. Target Risk PDE Publications, 1994
- The Isles report "Seat belt savings: Implications of European Statistics", UK DoT, 1981, Sourced from Death on the Streets, Cars and the Mythology of Road Safety by Robert Davis, Leading Edge Press, North Yorkshire UK, 1992 and "Report questions whether seat belts save lives" by M. Hamer, New Scientist, 7 February 1985 p7
- Evaluation of Automobile Safety Regulations: The case of Compulsory Seat Belt Legislation in Australia. by J.A.C. Coneybeare, Policy Sciences 12:27-39, 1980
- Compulsory Seat Belt Use: Further Inferences, by P. Hurst Accident Analysis and Prevention., Vol 11: 27-33, 1979
- Wilde G.S. Risk Homeostasis and Traffic Accidents Propositions, Deductions and Discussion of Dissension in Recent Reactions, Ergonomics 1988 Vol, 31, 4:439
- Methodological Issues in Testing the Hypothesis of Risk Compensation by Brian Dulisse, Accident Analysis and Prevention Vol. 25 (5): 285-292, 1997
- RS 255 The initial impact of seat belt legislation in Ireland by R. Hearne, An Foras Forbatha, Dublin, 1981
- The efficacy of seat belt legislation: A comparative study of road accident fatality statistics from 18 countries, by J. Adams. Department of Geography University College, London 1981
- Casualty Reductions, Whose Problem? By F. West-Oram, Traffic Engineering and Control, September 1990
- The Puzzle of Seat Belts Explained, Press Release of the Annual Conference of the British Psychological Society, April 1999
- Reconsidering the effects of seat belt Laws and Their Enforcement Status by T.S. Dee Accident Analysis and Prevention., Vol 30(1): 1-10, 1998