Citation

Elvik R. Accid. Anal. Prev. 2018; 113: 224-235.

Affiliation

Institute of Transport Economics, Gaustadalleen 21, Oslo NO-0349, Norway. Electronic address: re@toi.no.

Copyright

(Copyright © 2018, Elsevier Publishing)

DOI

10.1016/j.aap.2018.02.004

PMID

29428641

Abstract

Interactions characterise the relationship between use of amphetamines, cannabis and opiates as a driver and the risk of traffic injury associated with the use of these drugs. Inverse risk curves have been found for these drugs, meaning that the higher the proportion of drivers in normal traffic testing positive for the drugs, the lower is the increase in risk associated with them. The inverse risk curves can arise in many ways. The paper discusses ten different interpretations of the curves; seven of these are methodological and claim that the risk curves are statistical artefacts. Some support for these interpretations is found; however, this does not rule out that substantive interpretations, proposing causal mechanisms underlying the curves may also be correct. Unfortunately, there is insufficient evidence to assess the support for the substantive interpretations. There is, accordingly, a large element of uncertainty about how the inverse risk curves arise and whether they can be modified.


Keywords: Cannabis impaired driving


Copyright © 2018 Elsevier Ltd. All rights reserved.

Language: en

Keywords

Illicit drugs; Meta-analysis; Methodological interpretations; Risk of traffic injury; Substantive interpretations