The issue of driving under the influence of drugs (DUID) has been percolating as a traffic safety issue for many years. While many in the public safety field have believed it may be a significant problem, there has been little quantifiable data to confirm its magnitude. Serious gaps in national crash data exist.  After almost 40 years since the Department of Transportation’s Fatal Analysis Reporting System (FARS) program was initiated, only 33 percent of the drivers in fatal crashes are being tested with known test results.

However, recent studies have confirmed DUID is a significant traffic safety concern. The NHTSA 2006 National Roadside Survey showed that over 16 percent of nighttime drivers tested positive on an oral fluid or blood drug test (as compared to two percent who tested at or above a .08 percent BAC limit). A 2009 study published in the Journal of Forensic Sciences that examined fatally injured drivers in Washington State showed 39 percent of fatally injured drivers had drugs in their system. A 2005 study published in Accident Analysis and Prevention examined seriously injured motor vehicle crash victims admitted to the Maryland Shock Trauma Center and showed that over 50 percent of drivers admitted to the center had drugs in their systems.

Driving under the influence of drugs is a very complex issue. The challenge presented by this research is that the mere presence of drugs does not necessarily confirm driver impairment. Many studies have concluded that specific drug concentration levels cannot be reliably equated with effects on driver performance. There is no BAC chart of impairment for drug- impaired driving.

Another complicating factor is that many drug categories may be detected long after the potential for driving impairment has passed.  For example, presence of marijuana may be detected for weeks after ingestion by heavy or chronic users.

Additionally, a number of positive drug tests were for legally prescribed drugs that may have been ingested at pharmaceutical levels. While it is legal to use these types of drugs, it is illegal to drive while impaired. Also, there are no laws that cover designer drugs (such as bath salts). The drugs and other substances that are considered controlled substances under the Controlled Substances Act are divided into five schedules found here, If a drug is not recognized as a controlled substance, DUID offenses involving that drug cannot be prosecuted.

This issue has reached a point where evidence shows it is a real highway safety issue and it has been a focus of the Office of National Drug Control Policy, the Department of Transportation and other traffic safety groups including MADD. The NTSB is also likely to issue strong recommendations regarding DUID. The question is: Will the states and communities have the necessary resources to combat this emerging highway safety issue? Significant hurdles must be overcome before DUID can be more effectively addressed such as:

Lack of Trained Law Enforcement Personnel

Law enforcement officials have some reliable weapons to use in identifying potential DUID offenders, but they are not available to the vast majority of traffic law enforcement officers. NHTSA’s Drug Evaluation Classification program, of which drug recognition experts (DREs) are a part, has only a few thousand officers nationwide to identify these drivers. The Advanced Roadside Impaired Driving Enforcement (ARIDE) program has promise, but is still in its infancy and is dependent upon DREs for final arrest decisions.

Most departments do not have trained DREs. Several states have less than five DREs and some only have one per county. Traffic units across the country are being drastically reduced or even eliminated due to budget constraints.  Even many state police/patrol forces are being reduced. Many additional priorities demand officers’ time, such as distracted driving and occupant protection.

Limited Testing Protocols

Testing protocols are limited. For the most part, officers who make arrests for DUID have to rely on urine or blood tests to confirm the presence of drugs. These arrests are usually made when a suspected DWI offender is heavily impaired, but the BAC level is considerably lower (below the .08 percent BAC level) than what would be expected for the observed level of impairment. Often these offenders are released because the officers do not believe they have the ability to make a case for DWI and lack adequate knowledge/experience with DUID to make their case on DWI drug impairment.

Difficulty Obtaining Blood Samples

The ability to draw blood samples has created evidential problems for some jurisdictions. A number of medical facilities have not been cooperative in taking samples from DWI offenders. Uniform policy provision laws (alcohol exclusion laws) in some states make it difficult for these facilities to get reimbursed for their services. Many departments do not have ready access to appropriate labs to conduct the testing of the samples or are limited by budget concerns.

Per Se Legislation

Most states lack legislation to facilitate the collection and testing of fluid samples. According to a NHTSA 2010 Report to Congress, only 17 states (Arizona, Delaware, Georgia, Illinois, Indiana, Iowa, Michigan, Minnesota, Nevada, Ohio, Pennsylvania, Rhode Island, Utah, Virginia, and Wisconsin) have definitive drugged driving per se legislation that prohibits people from driving with drugs in their system. With no BAC impairment chart for drugs and no clear idea of the amount of individual drugs that cause impairment, per se laws are very difficult to pass. Nevada, Ohio and Virginia have threshold limits to increase the likelihood that an offender has been using recently. But even with these laws there is also a great deal of confusion as to which drugs (legal or illegal) or categories of drugs to prohibit. Learn more on Per Se laws.

Lack of Screening Tools

Few screening tools exist to confirm arrest decisions based upon SFSTs and DRE examinations. A mobile oral fluid screening device is being field tested in several jurisdictions to determine its accuracy and reliability. A European device which tests fingerprints for drugs will be introduced in the U.S. in 2013. These screening instruments must undergo scientific scrutiny before they can be considered admissible in criminal prosecution. NHTSA has not created Federal performance standards for these devices. Assuming these hurdles can be addressed, widespread deployment of the devices would require considerable effort.

Prosecutor Training

Special training is needed for prosecutors to effectively prosecute DUID cases. While a small number of prosecutors are already trained in DUID prosecution, hundreds more still need such additional training. Delivery of existing DUID training materials will require time and resources.