On the impact of cannabis consumption on traffic safety: a driving simulator study with habitual cannabis consumers


To contribute to the ongoing discussion about threshold limits of Δ9-tetrahydrocannabinol (THC) in road traffic, a driving simulator study with 15 habitually cannabis consuming test persons was conducted. Probands were tested on different routes after consumption of a maximum of three cannabis joints, each containing 300 μg THC/kg body weight (sober testing as well as testing directly, 3 and 6 h after cannabis consumption). Accompanying the drives, medical examinations including a blood sampling were performed. Driving faults and distinctive features in the medical examinations were allocated certain penalty points, which were then summed up and evaluated using the ANOVA model. The results showed that very high CIF values > 30 as well as serum THC concentrations > 15 ng/ml significantly increased the number of penalty points, but no direct correlation to the THC concentrations in serum and/or CIF values was detected. Instead, the point in time after cannabis consumption seems to play an important role concerning driving safety: significantly more driving faults were committed directly after consumption. Three hours after consumption, no significant increase of driving faults was seen. Six hours after consumption (during the so-called subacute phase), an increase of driving faults could be noted although not significant. Considering the limitation of our study (e.g. small test group, no placebo test persons, long lasting test situation with possible tiredness), further studies focusing on the time dependant impact of cannabis consumption on road traffic are required.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6


  1. 1.

    Federal Highway Research Institute: DRUID project final report 2012. https://www.bast.de/BASt_2017/EN/Traffic_Safety/Subjetcs/druid/Final_Report.html. Accessed 18 Nov 2011

  2. 2.

    World Drug Report 2018 (United Nations publication, Sales No. E.18.XI.9)

  3. 3.

    Compton R (2017) Marijuana-impaired driving—a report to Congress. Washington, DC: National Highway Traffic Safety Administration. (DOT HS 812 440)

  4. 4.

    Bundesanstalt für Straßenwesen (2006) Cannabis und Verkehrssicherheit. Mangelnde Fahreignung nach Cannabiskonsum: Leistungsdefizite, psychologische Indikatoren und analytischer Nachweis. Heft M 182. Wirtschaftsverlag NW 2006. (bast.opus.hbz-nrw.de/volltexte/2011/227/pdf/M182.pdf)

  5. 5.

    Asbridge M, Hayden J, Cartwright J (2012) Acute cannabis consumption and motor vehicle collision risk: systematic review of observational studies and meta-analyses. BMJ 344:e536

    Article  Google Scholar 

  6. 6.

    Sewell RA, Poling J, Sofuoglu M (2009) The effect of cannabis compared with alcohol on driving. Am J Addict 18(3):185–193. https://doi.org/10.1080/10550490902786934

    Article  Google Scholar 

  7. 7.

    Ramaekers JG, Berghaus G, van Laar M, Drummer OH (2004) Dose related risk of motor vehicle crashes after cannabis use. Drug Alcohol Depend 73(2):109–119

    CAS  Article  Google Scholar 

  8. 8.

    Hartman RL, Huestis MA (2013) Cannabis effects on driving skills. Clin Chem 59(3):478–492. https://doi.org/10.1373/clinchem.2012.194381

    CAS  Article  Google Scholar 

  9. 9.

    Robbe H (1994) Influence of marijuana on driving. Institute for Human Psychopharmacology. University of Limburg, Maastricht

  10. 10.

    Lenne MG, Dietze PM, Triggs TJ, Walmsley S, Murphy B, Redman JR (2010) The effects of cannabis and alcohol on simulated arterial driving: influences of driving experience and task demand. Accid Anal Prev 42:859–866

    Article  Google Scholar 

  11. 11.

    Ramaekers JG (2018) Driving under the influence of cannabis. An increasing public health concern. JAMA 319(14):1433–1434. https://doi.org/10.1001/jama.2018.1334

    Article  Google Scholar 

  12. 12.

    Hartung B, Schwender H, Roth EH, Hellen F, Mindiashvili N, Rickert A, Ritz-Timme S, Grieser A, Monticelli F, Daldrup T (2016) The effect of cannabis on regular cannabis consumers’ ability to ride a bicycle. Int J Legal Med 130:711–721. https://doi.org/10.1007/s00414-015-1307-y

    Article  Google Scholar 

  13. 13.

    Ramaekers J, Kauert G, Theunissen E, Toennes S, Moeller M (2009) Neurocognitive performance during acute THC intoxication in heavy and occasional cannabis users. J Psychopharmacol 23(3):266–277

    CAS  Article  Google Scholar 

  14. 14.

    Daldrup T, Meininger I (1998) Begutachtung der Fahrtüchtigkeit unter Cannabis im Strafverfahren. In: Berghaus G, Krüger H-P, eds. Cannabis im Straßenverkehr. Stuttgart: G. Fischer; 1998:153–178

  15. 15.

    Drasch G, von Meyer L, Raider G, Jagerhuber A (2003) Absolute driving inability under the influence of cannabis: proposal for a threshold limit. Blutalkohol 40(4):269–286

    Google Scholar 

  16. 16.

    Schwope DM, Bosker WM, Ramaekers JG, Gorelick DA, Huestis MA (2012) Psychomotor performance, subjective and physiological effects and whole blood Δ9-tetrahydrocannabinol concentrations in heavy, chronic cannabis smokers following acute smoked cannabis. J Anal Toxicol 36(6):405–412. https://doi.org/10.1093/jat/bks044

    CAS  Article  Google Scholar 

  17. 17.

    Grotenhermen F, Leson G, Berghaus G, Drummer OH, Krüger HP, Longo M, Moskowitz H, Perrine B, Ramaekers JG, Smiley A, Tunbridge R (2007) Developing limits for driving under cannabis. Addiction 102:1910–1917. https://doi.org/10.1111/j.1360-0443.2007.02009.x

    Article  Google Scholar 

  18. 18.

    Drasch G, von Meyer L, Roider G, Staack RF, Pauk LD, Eisenmenger W (2006) Unfälle und reale Gefährdung des Straßenverkehrs unter Cannabis-Wirkung. Blutalkohol 43:441

    CAS  Google Scholar 

  19. 19.

    Micallef J, Dupouey J, Jouve E, Truillet R, Lacarelle B, Taillard J, Daurat A, Authié C, Blin O, Rascol O, Philip P, Mestre D (2018) Cannabis smoking impairs driving performance on simulator and real driving: a randomized, double blind, placebo-controlled, crossover trial. Fund Clin Pharmacol 32:558–570. https://doi.org/10.1111/fcp.12382

Download references


We are grateful to the B.A.D.S. (Bund gegen Alkohol und Drogen im Straßenverkehr) for supporting the study by providing the driving simulator and to Ms. and Mr. Blömers for handling it.

Author information



Corresponding author

Correspondence to Benno Hartung.

Ethics declarations

Ethical standards

The experiments of this study comply with the current German laws. The study protocol was pre-approved by the ethics committee of the University Hospital Düsseldorf.

Conflict of interest

The authors declare that they have no competing interest.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Tank, A., Tietz, T., Daldrup, T. et al. On the impact of cannabis consumption on traffic safety: a driving simulator study with habitual cannabis consumers. Int J Legal Med 133, 1411–1420 (2019). https://doi.org/10.1007/s00414-019-02006-3

Download citation


  • Cannabis
  • THC
  • Driving simulator
  • Road traffic
  • Safety to drive
  • Impairment
  • Subacute phase