Operational Criteria of Causality for Observational Road Safety Evaluation Studies
Abstract
Nine criteria are discussed: they can be used to assess whether the effects attributed to road safety treatments in studies evaluating the effects of such treatments are causal or merely reflect randomness, confounding, or noncausal statistical association. The criteria are to a major extent based on similar criteria developed in epidemiology to assess the causality of factors associated with diseases. The criteria are related to (a) the presence of a statistical association between a treatment and changes in road safety (effect), (b) the strength of the statistical association between treatment and effect, (c) the internal consistency of the statistical association between treatment and effect, (d) the clarity of the causal direction between treatment and effect, (e) the invariance of the statistical association between treatment and effect regarding confounding factors, (f) the identification and measurement of causal mechanisms generating the association between treatment and effect, (g) the possibility of giving a theoretical explanation of the association between treatment and effect, (h) the presence of a dose-response pattern in the association between treatment and effect, and (i) the specificity of the association between treatment and effect to the intended target group of the treatment. These criteria can be used to assess the quality of road safety evaluation studies. The more criteria a study satisfies, the better is its quality. Use of the criteria is illustrated by means of examples.
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References
1. Hill A. B. Environment and Disease: Association or Causation. Proceedings of the Royal Society of Medicine, Vol. 58, 1965, pp. 295–300.
2. Hennekens C. H. H., and Buring J. M. Epidemiology in Medicine. Little, Brown and Company, Boston, Mass., 1987.
3. Elwood J. M. Causal Relationships in Medicine. Oxford University Press, Oxford, England, 1988.
4. Rothman K. J., and Greenland S. Modern Epidemiology, rev. ed. Lippincott Williams and Wilkins, Philadelphia, Pa., 1998.
5. Thagard P. Explaining Disease: Correlations, Causes, and Mechanisms. Minds and Machines, Vol. 8, 1998, pp. 61–78.
6. Hume D. An Enquiry Concerning Human Understanding. Oxford University Press, Oxford, England, 1999 (originally published in Edinburgh, Scotland, 1748).
7. Hempel C. G. Aspects of Scientific Explanation and Other Essays in the Philosophy of Science. The Free Press, New York, 1965.
8. Hauer E. Cause and Effect in Observational Cross-Section Studies on Road Safety. Draft. FHWA, U.S. Department of Transportation, March 2005. http://ca.geocities.com/[email protected]/download.htm.
9. Elvik R. To What Extent Can Theory Explain the Findings of Road Safety Evaluation Studies? Accident Analysis and Prevention, Vol. 36, 2004, pp. 841–849.
10. Elvik R. Speed and Road Safety: Synthesis of Evidence from Evaluation Studies. In Transportation Research Record: Journal of the Transportation Research Board, No. 1908, Transportation Research Board of the National Academies, Washington, D.C., 2005, pp. 59–69.
11. Broughton J. The Effect on Motorcycling of the 1981 Transport Act. TRRL Research Report 106. Transport and Road Research Laboratory, Crowthorne, Berkshire, England, 1987.
12. Elvik R. Introductory Guide to Systematic Reviews and Meta-Analysis. In Transportation Research Record: Journal of the Transportation Research Board, No. 1908, Transportation Research Board of the National Academies, Washington, D.C., 2005, pp. 230–235.
13. Elvik R. Can We Trust the Results of Meta-Analyses? A Systematic Approach to Sensitivity Analysis in Meta-Analysis. In Transportation Research Record: Journal of the Transportation Research Board, No. 1908, Transportation Research Board of the National Academies, Washington, D.C., 2005, pp. 221–229.
14. Mountain L. J., Hirst W. M., and Maher M. J. Are Speed Enforcement Cameras More Effective Than Other Speed Management Measures? The Impact of Speed Management Schemes on 30 mph Roads. Accident Analysis and Prevention, Vol. 37, 2005, pp. 742–754.
15. Hirst W. M., Mountain L. J., and Maher M. J. Are Speed Enforcement Cameras More Effective Than Other Speed Management Measures? An Evaluation of the Relationship Between Speed and Accident Reductions. Accident Analysis and Prevention, Vol. 37, 2005, pp. 731–741.
16. Elvik R. The Effect on Accidents of Technical Inspections of Heavy Vehicles in Norway. Accident Analysis and Prevention, Vol. 34, 2002, pp. 753–762.
17. Amundsen F. H. Trafikkulykker og kjøreatferd på mørke og lyse vegdekker. TØI-notat 654. Transportøkonomisk Institutt, Oslo, Norway, 1983.
18. Kim D-G., and Washington S. The Significance of Endogeneity Problems in Crash Models: An Examination of Left-Turn Lanes in Intersection Crash Models. Accident Analysis & Prevention, Vol. 38, 2006, pp. 1094–1100.
19. Taylor M. C., Baruya A., and Kennedy J. V. The Relationship Between Speed and Accidents on Rural Single-Carriageway Roads. Report TRL511. U.K. Transport Research Laboratory, Crowthorne, Berkshire, England, 2002.
20. Greenland S. Invited Commentary: A Critical Look at Some Popular Meta-analytic Methods. American Journal of Epidemiology, Vol. 140, 1994, pp. 290–296.
21. Greenland S. Quality Scores Are Useless and Potentially Misleading: Reply to “Re: A Critical Look at Some Popular Analytic Methods.” American Journal of Epidemiology, Vol. 140, 1994, pp. 300–302.
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Article first published: January 2007
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