INJURY PREVENTION

Health Evidence Bulletins - Wales
Team Leader: Dr. Ronan Lyons

Date of Completion: 2.4.98

3:Road Traffic Accidents

This document is a supplement to, not a substitute for, professional skills and experience. Users are advised to consult the supporting evidence for a consideration of all the implications of a recommendation

The Statements The Evidence

3.1 Drink Driving
3.1a. Avoiding alcohol before driving prevents road traffic accidents. Excess alcohol is involved in 20% of all traffic related deaths in Britaini,ii.
(Health Gain Notation - 1 "beneficial")
i. Wagenaar AC. Methods used in studies of drink-drive control efforts: a meta-analysis of the literature from 1960-1991. Accident Analysis and Prevention 1995; 27(3): 307-316.
(Type IV evidence - observational studies)
ii. Gloag D. British road traffic deaths fall but casualties rise. British Medical Journal 1995; 311: 281.
http://www.bmj.com/cgi/content/full/311/7000/281/a
(Type IV evidence - observational studies)
3.1b. The use of remediation therapy for drink driving offenders will reduce the number that reoffend. Remediation therapy results in a 7-9% reduction in drinking/driving recidivism and alcohol-related crashesi.
(Health Gain Notation - 1 "beneficial")
i. Wells-Parker E, Bangert-Drowns R, Williams M. Final results from a meta-analysis of remedial interventions with drink/drive offenders. Addiction 1995; 90: 907-926.
(Type I evidence - systematic review)
3.1c. A reduction in the permitted Blood Alcohol Concentration to 50 mg/100 ml is likely to lead to a reduction in injuries. The Australian Capital Territory reduced the legal limit from 80 to 50 mg which led to a 41% reduction on incidence of driving with a blood alcohol concentration > 150 mg, and there were a third less injured drivers with a blood alcohol concentration > 80 mgi.
(Health Gain Notation - 1 " beneficial")
i. BMA Board of Science and Education. Driving impairment through alcohol and other drugs. London: British Medical Association, 1996.
(Type IV evidence - observational studies)

 

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3.1d. A far more extensive use of random breath testing, accompanied by a high level of publicity will lead to a reduction in injuries. To be most effective breath testing should be intensive and applied to everybody at a checkpoint and not depend on "due cause". New South Wales' adoption of this policy resulted in a sustained 20% reduction in fatalitiesi.
(Health Gain Notation - 1 "beneficial")
i. Peacock C. International policies on alcohol-impaired driving: A review. The International Journal of Addictions 1992; 27(2): 187-208.
(Type IV evidence - observational studies)
3.2 Car Restraint
3.2a. Strategies that increase the use of seat belts or child restraints will result in fewer injuries. A Transport Research Laboratory survey in April 1996 showed only 43% of teenagers and adult rear passengers wearing seat belts. Over 25% of 5-13 year olds were unrestrained. An unrestrained child travelling in a car is approximately 3 times more likely to sustain head injury than a restrained child i,ii,iii.
(Health Gain Notation - 1 "beneficial")
i. Preventing unintentional injuries in children and young adolescents. Effective Health Care Bulletin Vol. 2 No. 5. University of York: NHS Centre for Reviews and Dissemination, 1996.
(Type IV evidence - observational studies)
ii.Transport Research Laboratory. Restraint use by car occupants, 1994-96. Crowthorne: Transport Research Laboratory, 1996; LF2074.
(Type IV evidence - observational studies)
iii.Ruta D, Beattie T, Narayan V. A prospective study of non-fatal childhood road traffic accidents: what can seat restraint achieve? Journal of Public Health Medicine 1993; 15(1): 88-92.
(Type IV evidence - observational studies)
3.3 Speed Control
3.3a. Stricter enforcement of speed limits will result in fewer injuries. The overall contribution of speed to accidents is not known but is widely quoted to be one third of all fatalities. Introduction of speed cameras in West London over a 6 year period led to a threefold reduction in deaths, from 68 to 20 and a reduction in serious injuries by over a quarter from
813 to 596 i .
(Health Gain Notation - 1 "beneficial.")
i. Highways Agency. West London speed camera project: analysis of accident data 36 months before and 36 months after implimentation. London: London Research Centre,1997.
(Type IV evidence - observational studies)

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3.4 Road Design
3.4a. Safer design of roads and roadside environments will result in fewer injuries. Many improvements in the past have concentrated on built up areas. As deaths on rural roads become relatively more important (54% of all deaths in the United Kingdom in 1993) a matching shift in prevention effort, to rural roads is needed i .
(Health Gain Notation-1 "beneficial")
i. Preventing unintentional injuries in children and young adolescents. Effective Health Care Bulletin. Vol. 2 No. 5. University of York: NHS Centre for Reviews and Dissemination, 1996.
(Type III evidence - well designed non randomised trials)
3.4b. Roadside guardrails (crash barriers) and crash cushions will reduce injury severity. Roadside guardrails reduce the chance of sustaining a personal injury by about 50% and the chance of sustaining a fatal injury by about 45%i .
(Health Gain Notation - 1 "beneficial")
i. Elvik R. The safety value of guardrails and crash cushions: a meta-analysis of evidence from evaluation studies. Accident Analysis and Prevention 1995; 27(4): 523-549.
(Type IV evidence - meta-analysis of observational studies)
3.4c. Area wide traffic management schemes should be targeted at areas with high injury rates and will reduce pedestrian injury rates. The provision of crossing patrollers, measures to redistribute traffic, and the design of roads to reduce speeds are effective in reducing pedestrian injuries i .
(Health Gain Notation -1 "beneficial")
i. Preventing unintentional injuries in children and young adolescents. Effective Health Care Bulletin. Vol. 2 No. 5. University of York: NHS Centre for Reviews and Dissemination, 1996.
(Type III evidence - well designed non randomised trials)

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3.5 Vehicle Design
3.5a. A European Directive on Pedestrian Protection should be introduced to ensure all new cars are fitted with pedestrian protection features. Meanwhile, national legislation should prohibit the fitting of "bull bars" i,ii .
(Health Gain Notation - 1 "beneficial")
Fitting all vehicles with pedestrian protection features would lead to an estimated 7% reduction in pedestrian deaths, 21% reduction in serious injuries and 3.5% of cyclist deaths. Bull bars cause an estimated 2-3 deaths and 40 serious casualties each year.
i. Parliamentary Advisory Council for Transport Safety. Bull-bars. London: Parliamentary Advisory Council for Transport Safety, March 1997
(Type IV evidence - observational studies)
ii. Hardy BJ. A study of accidents involving bull bar equipped vehicles. Study No. 243 Crowthorne, Berkshire: Transport Research Laboratory, 1996.
(Type IV evidence - observational study)
3.5b. Permanently switched on lights on cars can reduce daytime road traffic accidents. A meta-analysis of 17 observational studies of the effect of daytime running lights found that there were 10-15% less multi party daytime crashes in cars with the lights switched oni. As they are observational studies there is a risk of uncontrolled confounding. For similar reasons daytime running lights are mandatory in motorcyles.
(Health Gain Notation - 2 "likely to be beneficial")
i. Elvik R. A meta-analysis of studies concerning the safety effect of daytime running lights on cars. Accident Analysis and Prevention 1996; 28(6): 685-694
(Type IV evidence - meta-analysis of observational studies)
3.6 Road Safety Education
3.6a. Road safety education for children will lead to a reduction in injuries. There is some evidence of benefit in education ie. safe places to cross and "Traffic Clubs" i,ii .
(Health Gain Notation -2 " likely to be beneficial")
i. Preventing unintentional injuries in children and young adolescents. Effective Health Care Bulletin. Vol. 2 No. 5. University of York: NHS Centre for Reviews and Dissemination, 1996.
(Type III evidence - well designed non randomised trials)
ii. Ozanne-Smith J, Sherrard J, Brumen IA, Shire of Bulla: Safe living programme. Victoria, Australia: Monash University Accident Research Centre, 1994.
(Type III evidence - well designed non randomised trials)
3.6b. Strategies to increase the wearing of cycle helmets will reduce the incidence of head injury. Compulsory wearing of cycle helmets is controversial. In Australia (Victoria) injury rate was lowered by legislation (70% reduction in head injury admissions or deaths over a 2-year period) but cycling use also decreased, thus losing some of the benefits of exercise. Community wide programmes seem to be more effective than isolated programmes through single organisations i,ii.
(Health Gain Notation - 2 " likely to be beneficial)
i. Preventing unintentional injuries in young people. Effective Health Care Bulletin. Vol. 2 No. 5. University of York: NHS Centre for Reviews and Dissemination, 1996.
(Type IV evidence - observational studies)
ii. Bergman AB, Rivera FP, Richards
DD.The Seattle children's bicycle helmet campaign. American Journal of Diseases in Childhood 1990; 144: 727-731.
(Type IV evidence - observational studies)

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Health Evidence Bulletins: Wales, Duthie Library, UWCM, Cardiff CF14 4XN. e-mail: weightmanal@cardiff.ac.uk