Introduction

Virginia legislation (§46.2-223.1) mandates the annual collection and reporting of data on driving under the influence (DUI) of alcohol, drugs, or both, overseen by the Department of Motor Vehicles (DMV) starting in 2024. This initiative aims to strengthen DUI law enforcement and improve data accuracy. To drive meaningful change, a thorough assessment of Virginia’s current data collection and reporting practices is essential. This will help identify opportunities for better resource allocation and areas for improvement.

Methods

The Virginia Tech Transportation Institute (VTTI) evaluated 13 objectives under § 46.2-223.1, covering topics such as the number of vehicles with ignition interlock devices (IIDs), law enforcement distribution by county, incarceration sentencing, license restrictions, and drug and alcohol enforcement measures. To achieve these goals, VTTI collaborated with various stakeholders to access necessary data.

Results

In several areas—including the number of charges and convictions, referrals to the Virginia Alcohol Safety Action Program (VASAP), and active IIDs—figures were higher in 2019, declined in 2020, and gradually increased again by 2023.

Peak Year (2019)

In 2019, DUI-related metrics, including charges, convictions, and referrals to VASAP, reached notable peaks, coinciding with increased law enforcement efforts. These peaks were observed across areas such as charges and convictions under § 18.2-266, active IIDs, underage drinking, and a high volume of standard field sobriety tests (SFSTs), special conditions hours, checkpoint contacts, and saturation patrols. The data suggests a correlation between enforcement and outcomes, though increased enforcement may reflect better detection rather than an actual rise in unsafe behaviors. More arrests and charges may result from intensified efforts, not necessarily from a higher prevalence of offenses.

Year of Decline (2020)

The decline in 2020 can likely be attributed to several factors related to COVID-19, including reduced law enforcement patrols, fewer specialized programs such as saturation patrols and checkpoints, and a decreased likelihood of officers administering breathalyzer tests. Furthermore, despite reduced traffic volumes, drivers who remained on the road may have exhibited riskier behaviors, such as speeding or impaired driving.

Years of Incremental Increase (2021 – 2023)

In 2021, Virginia legalized the recreational use and possession of cannabis, though the sale of recreational cannabis remains prohibited. This legalization may have led to an increase in driving under the influence, however, this finding is not conclusively determined by this study. The observed increase in DUI-related metrics from 2021 to 2023 may not necessarily reflect a rise in drug use but rather a return to pre-pandemic conditions as road traffic increased and enforcement programs resumed. Additionally, in 2023, changes to testing protocols—mandating blood tests for all drivers suspected of DUI—resulted in an almost 15-fold increase in positive cannabis test results compared to 2022.

DUI Charges

The study also looked at the effect of sentencing on the likelihood of repeat DUI-related offenses. The majority of DUI charges were filed under statute § 18.2-266,with 93.5% being reduced to lesser charges. This raises important questions about recidivism rates among individuals who received leniency compared to those formally charged with a DUI. The data indicates that some individuals qualified for DUI charges but were instead given lesser charges by law enforcement. However, the recidivism rates for both those initially charged with a DUI and those who received lesser charges remain unclear. It is crucial to determine whether individuals granted leniency are less likely to reoffend. Understanding the circumstances surrounding these charges could reveal which drivers might benefit from a one-time leniency and which may exploit the system. The current dataset, as maintained by the Supreme Court of Virginia, contains case numbers; however, these values do not appear to be applied on a per-defendant basis. Such information would be invaluable in determining recidivism and highlighting high-risk individuals.

Polydrug Use

The study also found that polydrug use was common among offenders. Analysis of drug testing among both commercial and non-commercial drivers showed significant drug use. Among those at or above the legal alcohol DUI limit, 47.6% of commercial drivers and 38.3% of non-commercial drivers tested positive for drugs. Notably, from 2019 to 2022, the percentage of non-commercial drivers with a blood alcohol concentration (BAC) of zero who tested positive for drugs rose dramatically. Conversely, the percentage of non-commercial drivers testing positive for drugs who also had a BAC of 0.08% or higher increased until 2021 but declined in 2022. It remains unclear whether this decline represents a true trend change or an anomaly influenced by other factors. Commercial drivers exhibited a similar pattern, with an increased proportion overall (i.e., regardless of BAC level) testing positive for drugs from 2019 to 2022. Of particular concern is the increasing number of those at or above the DUI level, which continues to increase through to 2022.

Data from the Department of Forensic Science revealed notable levels of concurrent alcohol and cannabis use. Among drivers with a BAC of zero, 20.4% tested positive for cannabis, rising to 30% for those with a BAC of 0.08% or higher. This rise in alcohol and cannabis use was particularly evident in 2023, with an almost 15-fold increase in the number of positive tests from 2022 to 2023 (i.e., 41 to 608). While this increase may suggest greater cannabis use among drivers following the legalization of cannabis in 2021, it may also be related changes in state toxicology testing protocols. As of 2023, all DUI-arrested drivers in Virginia are required to have blood samples tested for cannabis, leading to a significant increase in the total number of samples submitted for testing—from an average of 2,575 tests (2019-2022) to 4,306 in 2023—which coincides with the drastic increase in positive results for both BAC ≥ 0.08 and cannabis. This underscores the importance of thoroughly considering all aspects of blood sample collection and testing for alcohol and drugs when interpreting these results.

Recommendations

This report is based on data collected from six different state agencies and departments, which currently cannot be matched or linked. Ideally, as individuals move from initial roadside testing through forensic analysis, sentencing, and enrollment in programs, their data should be traceable from administration to release. Achieving this requires standardizing data across all agencies and departments. Additionally, assigning a unique identifier for each individual and case would facilitate the creation of a unified tracking system, which would enable accurate analyses, process evaluations, and the identification of repeat offenders, while also enhancing inter-agency communication.

Limitations

Much of the data were analyzed using raw counts. While these counts provide a broad overview, they overlook important nuances that can be revealed by incorporating rates. For instance, raw counts of DUIs or checkpoint contacts that seem high in populated areas may actually be less significant when adjusted for population size. Considering local demographics can offer deeper insights and highlight underserved communities that raw counts might miss.

Additionally, the location of an infraction determines where data are recorded, which may exclude individuals who travel into urban areas from predominantly rural regions. This affects data integrity, raising questions about whether resources should be focused on the site of the infraction (urban area) or the driver’s origin (rural area) to improve safety-related behaviors.

Lastly, drug metabolites remain detectable in the body for varying durations; thus, the presence of a metabolite does not necessarily indicate intoxication or the degree of intoxication.