# Novel approaches to assessing cannabis impaired driving

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2024 · $460,580

## Abstract

PROJECT SUMMARY
The ability of public safety personnel to identify cannabis impaired driving has lagged behind the
dramatic shifts in legal access to cannabis in the U.S. and other countries. Reducing the risk
related to cannabis impaired driving will depend on accurate methods to detect impairment and
evidence-informed guidance on how dose, route of administration, and temporal factors are
associated with impairment. We will leverage our operational driving simulator laboratory to test
innovative devices for accuracy and predictive value in identifying impairment from cannabis
use. We will test portable devices that measure psychomotor performance (on a tablet) and
oculomotor performance (in a goggle-based instrument). Using an efficient, within-subjects
design, performance on these devices will be compared to driving simulator measures obtained
before and after self-administered cannabis by occasional and daily cannabis users. We will
also examine the pharmacokinetic profile of THC (tetrahydrocannabinol) and its metabolites in
relation to pharmacodynamic measurements of psychomotor function. We will conduct 3 phases
of research over 5 years. In phase 1 we will collect standard venous and innovative (100 µL)
capillary blood samples before and after cannabis use among a cohort of cannabis users with
varied cannabis use histories (n=30) to examine the pharmacokinetic profile of blood
cannabinoids over time. In Phase 2, we will recruit a cohort of cannabis users to complete
assessments before and after smoking cannabis to examine the predictive value of established
psychomotor tests, ocular tests, and blood cannabinoid profiles against validated benchmarks of
driving simulator performance. A subgroup of non-using control subjects will be enrolled to
adjust for learning effects (total n=120). In Phase 3 we will use a similar approach to test the
effect of edible cannabis products on impairment (n=90). These innovative technologies are
highly portable and have the promise to offer an objective assessment of impairment due to
cannabis and other psychoactive drugs at or near the roadside or at the workplace. Successful
completion of our study will provide public health and safety officials, medical and recreational
cannabis users, health care providers, employers and the judicial system with novel information
regarding cannabis use and driving safety.

## Key facts

- **NIH application ID:** 10829900
- **Project number:** 5R01DA049800-05
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Ashley Brooks-Russell
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $460,580
- **Award type:** 5
- **Project period:** 2020-07-01 → 2025-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10829900

## Citation

> US National Institutes of Health, RePORTER application 10829900, Novel approaches to assessing cannabis impaired driving (5R01DA049800-05). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10829900. Licensed CC0.

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