Citation

Stephan E, Mattern R, Tschop T, Skopp G. Blutalkohol 2004; 41(6): 25-37.

Affiliation

Psychologisches Institut, Universitat zu Koln, Lehrst. Psychol. Diagn./Intervention, 50931 Koln, Germany

Copyright

(Copyright © 2004, International Committee on Alcohol, Drugs and Traffic Safety and Bund gegen Alkohol und Drogen im Straßenverkehr, Publisher Steintor Verlag)

DOI

unavailable

PMID

unavailable

Abstract

It is necessary to conduct more empirical studies regarding the impairment of traffic-relevant performance due to the consumption of illegal drugs. Studies of the relevance of illegal drubtaking in traffic are presented and the advantages and disadvantages of field examinations and laboratory tests are discussed. After that a survey of the university of Cologne in cooperation with the university of Heidelberg is presented which used a particularly close-to-reality design to measure the performance impairment by cannabis consumption relevant for traffic. 30 Guests of a Dutch "Coffeeshop" were examined (16 m, 14 f). The participants accomplished a driving simulation (short version of the K-Vebis) three times: First - after self-assessment of the readiness to drive - the simulation was executed without the influence of marijuana. After that the subjects were asked to smoke a marijuana cigarette ("Joint"). They had the choice between a dose of 12.5 mg and 25 mg of THC of the sort "White Widow". After the renewed self-estimation of the readiness to drive the driving simulation was performed once again after a break of approx. 20 minutes - this time under acute cannabis influence. Then the participants were asked to perform the driving simulation again as soon as they felt able to drive again. Immediately before the beginning of the simulation they should estimate their driving ability. Now the driving simulation took place under sub-acute marijuana influence. The driving performances were much lower under acute marijuana influence than when sober. In all driving situations, e.g., the performance of the driving was substantially impaired. The strongly impaired performance of the secondary task shows higher cognitive demands by the performance of the driving task. In a driving situation in which the speed could be chosen freely the participants under acute cannabis influence drove approx. 38 km/h slower than without drug influence.

Keywords: Cannabis impaired driving