Drug-Impaired Driving Patterns in Munich During the COVID-19 Pandemic
Cannabis remained the most commonly detected substance in drug-related traffic stops in Munich throughout the pandemic, with THC-COOH levels rising during lockdowns.
Quick Facts
What This Study Found
Among 6,210 blood samples from substance-related traffic stops in Munich (2019-2021), cannabis was detected most frequently (66-67%), followed by alcohol (11%) and cocaine (5%). Detection patterns were largely stable across the pandemic. However, THC-COOH concentrations were higher during the pandemic, and alcohol was more common in e-scooter riders during lighter restrictions.
Key Numbers
6,210 blood samples analyzed. Cannabis detected in 66.2% pre-pandemic, 67.4% during pandemic. Alcohol: 11.7% vs 10.8%. Cocaine: 5.7% vs 5.2%. THC-COOH concentrations were higher during the pandemic. Alcohol levels rose during light restrictions and fell during strict lockdowns.
How They Did This
Retrospective analysis of 6,210 blood samples from individuals suspected of substance-related traffic offenses under German law between January 2019 and July 2021. Samples stratified by pre-pandemic and pandemic periods, with pandemic periods subdivided by restriction severity.
Why This Research Matters
Understanding how pandemic conditions affected substance-impaired driving patterns can help cities prepare traffic safety measures during future disruptions and informs ongoing debates about cannabis and driving policy.
The Bigger Picture
The stability of cannabis detection rates despite pandemic disruptions suggests that cannabis-impaired driving is a persistent baseline issue rather than one driven by social circumstances. The e-scooter finding highlights emerging vehicle-specific safety concerns.
What This Study Doesn't Tell Us
Single city (Munich) limits generalizability. Only captures individuals who were stopped and tested. Cannot determine impairment level from THC-COOH (an inactive metabolite). No data on crash outcomes or severity.
Questions This Raises
- ?Did the higher THC-COOH levels during the pandemic reflect increased use or more concentrated products?
- ?How do e-scooter DUI patterns compare to other European cities?
Trust & Context
- Key Stat:
- Cannabis was detected in 66-67% of substance-related traffic stops in Munich, stable through the pandemic
- Evidence Grade:
- Large sample from systematic testing in a single city. Retrospective design and single-city scope limit broader conclusions.
- Study Age:
- 2025 publication analyzing 2019-2021 data from Munich.
- Original Title:
- Quantitative and qualitative changes in substance-related administrative offences in road traffic during the SARS-CoV-2 pandemic in Munich.
- Published In:
- PloS one, 20(10), e0334598 (2025)
- Authors:
- Holzer, Anna, Stoever, Andreas, Lau, Michael, Gleich, Sabine, Graw, Matthias, Ludwig, Anouk, Hartung, Benno
- Database ID:
- RTHC-06676
Evidence Hierarchy
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-06676APA
Holzer, Anna; Stoever, Andreas; Lau, Michael; Gleich, Sabine; Graw, Matthias; Ludwig, Anouk; Hartung, Benno. (2025). Quantitative and qualitative changes in substance-related administrative offences in road traffic during the SARS-CoV-2 pandemic in Munich.. PloS one, 20(10), e0334598. https://doi.org/10.1371/journal.pone.0334598
MLA
Holzer, Anna, et al. "Quantitative and qualitative changes in substance-related administrative offences in road traffic during the SARS-CoV-2 pandemic in Munich.." PloS one, 2025. https://doi.org/10.1371/journal.pone.0334598
RethinkTHC
RethinkTHC Research Database. "Quantitative and qualitative changes in substance-related ad..." RTHC-06676. Retrieved from https://rethinkthc.com/research/holzer-2025-quantitative-and-qualitative-changes
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.