Drug-Impaired Driving: Additional Support Needed for Public Awareness Initiatives
Published: 2015-02-24T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: The issue of alcohol-impaired driving has received broad attention over the years, but drug-impaired driving also contributes to fatalities and injuries from traffic crashes. However, knowledge about the drug-impaired- driving problem is less advanced than for alcohol-impaired driving.
Through Senate Report No. 113-45 (2013), Congress required GAO to report on the strategies NHTSA, ONDCP, and states have taken to address drug-impaired driving and challenges they face in detecting and reducing such driving. This report discusses (1) what is known about the extent of drug-impaired driving in the United States; (2) challenges that exist for federal, state, and local agencies in addressing drug-impaired driving; and (3) actions federal and state agencies have taken to address drug-impaired driving and what gaps exist in the federal response. GAO reviewed literature to identify sources of data on drug-impaired driving; reviewed documentation and interviewed officials from NHTSA, ONDCP, and HHS; and interviewed officials from relevant advocacy and professional organizations and seven selected states. States were selected based on: legal status of marijuana, proximity to states with legalized marijuana, and drugged-driving laws.
section_title: What GAO Found
paragraphs: Various state and national-level data sources—including surveys, arrest data, drug-testing results, and crash data—provide limited information on the extent of drugged and drug-impaired driving in the United States. For example, based on preliminary results from a representative sample of weekend-nighttime and Friday daytime drivers, the National Highway Traffic Safety Administration's (NHTSA) 2013-2014 National Roadside Survey of Alcohol and Drug Use by Drivers ( NRS ) estimated that 20 percent of drivers would have tested positive for at least one drug, with marijuana being the most common drug. However, the survey does not capture the extent to which drivers were impaired by drugs. Arrest data and drug-testing results provide some information on drug-impaired driving, but these data are limited. For example, data for drug impairment may not be separated from that for alcohol impairment and drug testing is not standardized. According to NHTSA officials, currently available data on drug involvement in crashes are generally unreliable due to variances in reporting and testing.
The lack of a clear link between impairment and drug concentrations in the body makes it difficult to define drug impairment, which, in turn, exacerbates challenges related to enforcement and public awareness. Compared to alcohol, defining and identifying impairment due to drugs is more complicated due to the large number of available drugs and their unpredictable effects. For example, the NRS includes tests for 75 illegal prescriptions, and over-the-counter (OTC) drugs identified as potentially impairing. Additionally, law enforcement processes for obtaining samples for drug testing can be time consuming and result in a loss of evidence. For example, there is no validated device for roadside drug testing, and obtaining a search warrant to collect a blood sample to confirm the presence of drugs in a driver's system could take several hours, during which time the concentration of the drug in the driver's system could dissipate. Further, state officials identified limited public awareness about the dangers of drugged driving as a challenge. As a result, members of the public may drive while impaired without knowing the risks, potentially leading to collisions, injuries, and fatalities.
Federal and state agencies—including NHTSA, the White House Office of National Drug Control Policy (ONDCP), and the Department of Health and Human Services (HHS)—are taking actions to address drug-impaired driving, including improvements in the areas of research and data, education for police officers, evidence gathering, and legal changes. For example, NHTSA is currently conducting research to assess the crash risk associated with drug use (including illegal, prescription, and OTC drugs) by collecting samples from more than 10,000 drivers. However, public awareness of the dangers of drug-impaired driving is an area in which state officials told us that NHTSA could do more to support their efforts. As part of its mission to support state safety efforts, NHTSA has provided media and other materials to states for impaired-driving awareness programs, but these materials are focused on alcohol-impaired driving. While NHTSA plans to improve public awareness through initiatives to conduct surveys on drug-impaired-driving behaviors and attitudes as well as training for medical professionals, these plans could take several years to implement. Additional efforts, such as general messaging reminding the public about the impairing effects of drugs, could help improve public awareness in the near term.
section_title: What GAO Recommends
paragraphs: GAO recommends that NHTSA take additional actions to support states in emphasizing to the public the dangers of drug-impaired driving. DOT agreed with GAO's recommendation.

section_title: Letter
paragraphs: While the issue of alcohol-impaired driving has received broad attention  over the years, drug-impaired driving also contributes to fatalities and  injuries from traffic crashes. However, knowledge about the nature of the  drug-impaired driving problem is significantly less advanced than for  alcohol-impaired driving. Based on preliminary results from a nationally  representative sample in 2013-2014, an estimated 20 percent of nighttime  weekend drivers would have tested positive for illegal, prescription, or  over-the-counter (OTC) drugs that have been identified as potentially  impairing. The White House’s Office of National Drug Control Policy  (ONDCP) has identified “drugged driving” as a policy priority, and  established a goal in the agency’s 2011 National Drug Control Strategy to  reduce drugged driving 10 percent by 2015.Traffic Safety Administration (NHTSA) assists states in implementing  programs to address impaired driving—including those aimed at reducing  drug-impaired driving—and has funded research examining the extent  and nature of drug-impaired driving as well as the effectiveness of  countermeasures.
The Senate Report accompanying the Transportation and Housing and  Urban Development, and Related Agencies Appropriations Bill, 2014  required GAO to report on the strategies that NHTSA, ONDCP, and  states have taken to address drug impairment and the challenges faced  in detecting and reducing drug-impaired driving. (1) what is known about the extent of drug-impaired driving in the United  States; (2) challenges that exist for federal, state, and local agencies in  addressing drug-impaired driving; and (3) actions federal and state  agencies have taken to address drug-impaired driving and gaps that exist  in the federal response to drug-impaired driving.
This report uses the term “drug-impaired driving” to refer to driving while  impaired by illegal drugs or prescription and OTC (legal) medications. For  this work, we conducted a literature search to identify sources of data and  studies on the issue and extent of drug-impaired driving, reviewed these  data and studies, and determined their limitations. Additionally, we  reviewed documentation and interviewed officials from seven federal  agencies: NHTSA; ONDCP; National Transportation Safety Board  (NTSB); Department of Health and Human Services (HHS) and  component agencies including the Substance Abuse and Mental Health  Services Administration (SAMHSA), Centers for Disease Control and  Prevention (CDC), Food and Drug Administration (FDA), and National   We also reviewed documentation obtained  Institutes of Health (NIH).
S. Rep. No.113-45 (2013). from and interviewed officials with responsibilities related to drug-impaired  driving, such as traffic safety, toxicology lab, and law enforcement  officials, in seven states (Arizona, California, Colorado, Kansas, Ohio,  Vermont, and Washington). We selected these states based on  recommendations from federal officials and representatives from  advocacy and professional organizations and to represent a variety of  laws, programs, and other factors. Our selection included:  states with legalized recreational marijuana,  states that geographically border states in which recreational  marijuana use is legal, states with legalized medical marijuana, states representing a variety of drug-impaired driving laws, and states identified as having robust programs dealing with driving under  the influence of drugs.
We also reviewed documentation and interviewed representatives from  advocacy and professional organizations, including the Governors  Highway Safety Association (GHSA), National District Attorneys  Association, Society of Forensic Toxicologists, Inc. (SOFT), Mothers  Against Drunk Driving (MADD), International Association of Chiefs of  Police (IACP), Insurance Institute for Highway Safety, and National  Conference of State Legislatures (NCSL). See additional information on  our scope and methodology in appendix I.
We conducted this performance audit from April 2014 through February  2015 in accordance with generally accepted government auditing  standards. Those standards require that we plan and perform the audit to  obtain sufficient, appropriate evidence to provide a reasonable basis for  our findings and conclusions based on our audit objectives. We believe  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.
subsections: section_title: Background
paragraphs: Similar to drunk driving, drug-impaired driving can result in crashes  leading to death or injury of vehicle occupants and pedestrians, along  with other safety and traffic issues for individuals and society. Taking into  consideration these possible harms, Congress has authorized grant  funding to states to combat impaired driving through transportation  legislation—most recently the Moving Ahead for Progress in the 21st  Century Act (MAP-21). These grant programs are designed to  encourage states to adopt and implement effective programs to reduce  driving under the influence of alcohol, drugs, or the combination of alcohol  and drugs. Historically, these programs have been focused on reducing  alcohol-impaired driving. For example, in the late 1990s, Congress made  grant funds available to states to encourage them to lower the illegal per  se driving blood-alcohol concentration (BAC) limit to 0.08.words, with respect to a BAC limit of 0.08, anyone whose blood contains  8/100th of 1 percent of alcohol (or higher) would be deemed to be driving  while intoxicated. All 50 states and the District of Columbia have 0.08  laws as well as laws making it illegal to drive while impaired by drugs.
NHTSA administers grant programs for safety initiatives to assist states in  their efforts to reduce traffic-related fatalities, including fatalities involving  drug- and alcohol-impaired driving. NHTSA also provides guidance and  technical assistance to states, and conducts research on drivers’ behavior  and traffic safety. As part of such research, NHTSA works with traffic  safety organizations, such as GHSA and MADD, and other federal  agencies, such as ONDCP. In addition to NHTSA, other federal agencies  conduct research and implement programs that, in whole or in part, seek  to increase knowledge about the problem of drug-impaired driving and to  identify and implement policies and programs to reduce drug-impaired  driving. These agencies include ONDCP; HHS’s SAMHSA, NIH, FDA,  and CDC; Department of Justice (DOJ); and NTSB.
Drug-impaired driving may be caused by use of illegal drugs, legally  prescribed or OTC drugs that are misused, and some legally prescribed  or OTC drugs even when used as intended. While 23 states and the  District of Columbia have legalized the use of marijuana for medical  purposes, according to the NCSL, and two states—Colorado and  Washington—allow the use of marijuana for recreational purposes, the  federal government continues to consider marijuana as an illegal drug,  with no medical use.which data may include marijuana as either a legal or illegal drug.  According to the FDA, some prescription and OTC drugs can impair  driving ability, while others have no effect or can even enable patients to  drive more safely.
Throughout the report, we have noted instances in  For the purposes of this report, we have used the following terminology:
Drugged driving: driving with the presence of drugs in one’s system  regardless of impairment.
Drug-impaired driving: driving with a diminished ability to operate a  vehicle due to drug use.
Drug test: the toxicological analysis of a biological specimen—blood,  urine, or oral fluid (saliva)—to determine the presence or absence of  specific drugs or their metabolites.
DUI: driving under the influence of alcohol and/or drugs.
DUID: driving under the influence of drugs.
Impairment: a diminished ability to perform specific functions.
Metabolites: the products of drug metabolism found in bodily fluids,  which indicate prior drug use.
Tetrahydrocannabinol (THC): the main psychoactive compound  found in the cannabis (marijuana) plant.
Toxicology: the study of the effects of drugs—whether illegal,  prescription, or over-the-counter—on humans.
Drugs may be categorized in several ways including by the chemical type  or by the way the drug is used. For example, this report uses the following  terms to classify drugs, among others:
Antidepressants: drugs used to treat depression and other  conditions, including anxiety disorders.
Cannabinoids: compounds contained in marijuana.
Narcotics: drugs including opium and those derived from it, such as  heroin and codeine.
Depressants: drugs that inhibit the activity of the brain and may result  in muscle relaxation, lowered blood pressure and heart rate, and  slowed breathing; includes anxiety and seizure medications.
Stimulants: drugs that may result in increased alertness and elevated  heart rate and respiration; includes cocaine and amphetamines.
Synthetics: synthetic drugs, as opposed to natural drugs such as  marijuana, are chemically produced in a laboratory to mimic the  effects of other drugs. Synthetic drugs may be developed in order to  circumvent existing drug laws. Examples include synthetic  cannabinoids and cathinones.
section_title: Limited Data Exists on the Extent of Drug- Impaired Driving in the U.S.
paragraphs: There is no national source of data on the extent of drug-impaired driving  in the United States, but various state and national sources of data on  drugged driving can provide limited information on the extent to which  drivers in the United States have drugs in their systems. For example,  national and state roadside surveys provide information on the  prevalence of drugged driving in respective survey areas. Other sources  of data provide some information on drugged and drug-impaired driving,  such as surveys on self-reported drugged-driving behavior, impaired-  driving arrests and toxicology results, and crash data. However,  limitations to the currently available data include underreporting and a  lack of centralization or standardization in reporting.
subsections: section_title: Survey Data on Prevalence of Drugged Driving
paragraphs: National and state roadside surveys provide data on the prevalence of  drugged driving in statistically representative samples of drivers. For  example, NHTSA’s 2007 National Roadside Survey of Alcohol and Drug  Use by Drivers (NRS) provides information on drivers testing positive for  illegal, prescription, and OTC drugs in a nationally representative sample  of weekend-nighttime and Friday daytime drivers. Based on the 2007  survey, NHTSA estimated that 16.3 percent of nighttime drivers  nationwide would have tested positive for at least one drug, with  marijuana being the most common drug found in test results (see table 1).  While NRS survey data provides useful information on the estimated  prevalence of drugged driving, these results do not measure the extent to  which drivers are impaired by the drugs in their systems as the presence  of drugs or drug metabolites does not necessarily indicate impairment.  For example, marijuana metabolites can be detected in blood samples  several weeks after daily users’ last use. Nonetheless, the 2007 NRS  provided the first objective data on drug use among drivers in the United  States and, according to officials at the National Institute on Drug Abuse  (NIDA) and SOFT, served as a wake-up call regarding the extent of  drugged-driving in the United States. According to NHTSA, the survey  was repeated in 2013-2014 following the same general methodology as  the 2007 survey and results will be available in 2015. Preliminary results  from that survey estimated that 20 percent of nighttime weekend drivers  would have tested positive for illegal, prescription, or OTC drugs that   An assessment of trends  have been identified as potentially impairing.in drugged driving in the United States may be feasible as future results  beyond the 2013-2014 NRS become available. Table 1 shows additional  drug test results from this survey.
Lacey et al. The NRS methodology involves randomly stopping drivers at locations  Poly-Use (more than one class of drug)
During nighttime weekend times, drivers were tested for the presence of drugs using oral fluid. A  positive oral fluid test is a positive drug test.
California’s Office of Traffic Safety found results similar to the 2007 NRS  during its 2012 California Roadside Survey of Nighttime Weekend  Drivers’ Alcohol and Drug Use (see table 1). Specifically, 14 percent of  nighttime weekend drivers tested positive for at least one drug, with  marijuana being the most frequent drug identified. Additionally, the  Washington Traffic Safety Commission has commissioned the first of two  roadside surveys, using what NHTSA describes as comparable  methodology to the 2007 NRS, meant to measure drug and alcohol use  among drivers before and after implementation of the 2012 state law  legalizing recreational marijuana use. Results from the survey are  expected in 2015.
section_title: Surveys on Drug Use Behavior
paragraphs: The NRS and California surveys also collected self-reported data on drug  use among drivers who participated in the survey. For instance, during  the California Survey, approximately 14 percent of all drivers who  reported having used marijuana in the past reported having used it within  2 hours of driving in the past year. In the NRS, all drivers who provided an  oral fluid sample were asked to report if they had used a drug before  driving and, if so, what type. For the subset of Friday and nighttime  weekend drivers who tested positive for at least one drug based on the  oral fluid sample, the drivers’ answers regarding prior drug use were  compared to positive oral fluid-analysis results to determine agreement  between self-reported behavior and the oral fluid test. Results of this  comparison include: an estimated 7.5 percent of nighttime weekend drivers testing positive  for cocaine reported they had used cocaine in the past 24 hours, an estimated 25.7 percent of nighttime weekend drivers testing  positive for marijuana reported they had used marijuana in the past 24  hours, an estimated 59.9 percent of nighttime weekend drivers testing  positive for pain medication reported they had used pain medication in  the past 24 hours, and an estimated 66.4 percent of nighttime weekend drivers testing  positive for antidepressants reported they had used antidepressants  in the past 24 hours.
Agreement between reported drug use in the past 24 hours and positive  oral-fluid-analysis results for the nighttime-driving samples was greatest  among users of antidepressants, cough suppressants, and pain  medications and lowest for amphetamines and barbiturates.reported data may be useful in tracking trends in reported drug use and  attitudes about drugged driving, the NRS methodology noted that it may   While self- under-report actual activity and therefore be insufficient for estimating the  extent of drugged driving.
Additional studies compile self-reported data on attitudes and behaviors  regarding drug use and driving, which may be helpful in tracking trends in  behavior. SAMHSA’s National Survey on Drug Use and Health (NSDUH)  is an annual survey of a nationally representative sample of the United  States population. The NSDUH includes questions specific to driving  while under the influence of illegal drugs. According to this survey, driving  under the influence of illegal drugs is most common in respondents aged  18–25 (an estimated 10.6 percent in 2013, the latest survey results  available). Overall, the percentage of respondents aged 12 or older who  report driving under the influence of illegal drugs in the past year has  been around 4 percent from 2008 through 2012. NIH’s NIDA also  supports various studies on drug use including the College Life Study on  health-related behaviors of college students, and Monitoring the Future,  which measures attitudes of adolescents related to drug and alcohol  use. According to the 2012 Monitoring the Future Survey, an estimated  10.6 percent of high school seniors drove a car, truck, or motorcycle in  the prior 2 weeks after having smoked marijuana.
section_title: Data on Impaired-Driving Arrests and Toxicology Results
paragraphs: Data on drug-impaired driving arrests and toxicology results in our seven  selected states provide some information on drug-impaired driving, but  are limited by a lack of separation of data from driving under the influence  (DUI) arrests, underreported instances of drug-impaired driving,  decentralized reporting, and a lack of standardization in drug testing. For  example, officials in six of the seven selected states told us that state  arrest data does not currently separate data on drug-impaired driving and  alcohol-impaired driving cases across law enforcement agencies. Officials  from California stated that although the state recently revised its vehicle  code to delineate DUI into three separate reportable sections, it could be  several years until any data generated from the new system can be   Arizona’s Governor’s Office of  considered complete and accurate.Highway Safety tracks arrests for driving under the influence of alcohol  and drugs separately, and data show an increase in drug-impaired driving  arrests in the past 5 years, but this rise does not necessarily indicate an  increase in drug-impaired driving. For example, Arizona data show a 966  percent increase in drug-impaired driving arrests from 2005 through 2013.  However, the increase in arrests may be due to the 659 percent increase  in the number of officers participating in impaired-driving enforcement  activities, the 1,604 percent increase in the number of traffic stops, and  better reporting of those traffic stops, rather than an increase in drug- impaired driving. The rates of contacts resulting in DUID arrests do not  show an increasing trend. See table 2.
In addition, drug-impaired driving may be underreported as drivers  impaired by both alcohol and drugs will likely be tested and prosecuted  only for alcohol impairment because, according to officials from NHTSA  and six of the seven selected states, evidence collection and prosecution  are much easier for alcohol-impaired driving. Officials from NHTSA and  six states said that in general, if a person suspected of impaired driving  has a BAC over 0.08, the individual is not tested further for the presence  of drugs, regardless of whether drug impairment is also suspected. As a  result, drivers impaired by both drugs and alcohol may not be reported  accurately in arrest data, contributing to a lack of knowledge about the  number of drivers impaired by both drugs and alcohol.
Further, based on our review of information from the seven selected  states on arrests and toxicology results for DUID cases, we found that  state data on impaired driving are often not centralized or complete.  Among the selected states, data on DUID arrests are generally collected  by local law enforcement agencies, and one of the seven selected states  collects statewide data on DUIDs in a centralized database. While  Arizona collects arrest data from a majority of its local law enforcement  agencies in a central database, a small number of local agencies do not  participate. One official estimated about 2 percent of agencies do not  submit data. Similarly, statewide toxicology/drug-testing data may not be  easily available because it is decentralized. In five of the seven selected  states, toxicology data are maintained by individual state and local law  enforcement agencies and toxicology labs (including private and public  labs), with no centralized database. For example in California, DUID  testing varies by jurisdiction and can be completed by one of 22 private  labs or 6 public labs at the local or state level. In contrast, Vermont and  Washington have centralized results of all DUID drug tests, which are  conducted by a single laboratory for each state. While Vermont toxicology  data do not show any clear trends, a study using Washington state  toxicology data indicates that the prevalence of marijuana in suspected  impaired-driving cases increased after marijuana was legalized, from an  average of 19.1 percent of cases positive for tetrahydrocannabinol   (THC) from 2009 through 2012 to 24.9 percent in 2013 (post  legalization). However, according to one of the authors, it is unclear  whether this increase is due to factors other than an increase in  marijuana-impaired driving, such as an increased focus on marijuana  impairment in the state. Over the same period, the prevalence of alcohol  and drugs other than marijuana in the population of suspected impaired  drivers remained relatively stable in Washington.
Further, drug test results may not be comparable among laboratories.  Officials from three of the seven selected states, as well as  representatives from SOFT, stated that a lack of standardization among  labs means that test results from different labs cannot necessarily be  compared. For example, labs do not have uniform reporting-level cutoffs  for drugs (the level at which a drug is reported as present). Therefore, for  the same sample, one lab may report the sample as positive for the  presence of a drug while another lab may report the sample as negative  because the amount present is below the reporting level cutoff for the  second lab. According to officials from HHS, while there are federal  standards for forensic toxicology testing for federal agencies and states  may establish standards for forensic testing, there are currently no federal   laboratory certification requirements for forensic laboratories conducting  toxicology testing for state and local law-enforcement agencies.
Despite these limitations, drug testing results for DUID cases can provide  information on the types and amounts of drugs present in drivers’  systems. A 2004–2005 survey of labs in the United States conducted by  SOFT, in conjunction with the National Safety Council and the American  Academy of Forensic Sciences, shows that the most common drug  encountered in DUID cases is cannabis (marijuana), followed by  benzodiazepines (anti-anxiety medications with sedative properties), then  narcotics (including cocaine, hydrocodone, and morphine/codeine).  The  most common drugs, and how drugs are categorized, differ from region to  region, as indicated by toxicological results we gathered from seven state  toxicology labs. Four of the selected states do not separate out DUID  toxicological testing from other toxicological testing. For the three  selected states that have separate toxicology data for DUID cases, the  most common drug found for the most recent data available was  marijuana; the second most common drug or drug category found was  methamphetamine for two states and benzodiazepines in one state.
section_title: Federal and State Crash Data
paragraphs: Laurel J. Farrell, Sarah Kerrigan, and Barry K. Logan, “Recommendations for  Toxicological Investigation of Drug Impaired Driving,” Journal of Forensic Sciences, vol.  52 no. 5 (2007). because of the limitations and variations in data collection, testing, and  reporting noted above, among other things.
section_title: Difficulty of Defining Drug Impairment Exacerbates Challenges Related to Enforcement and Public Awareness
paragraphs: In addition to limited data on the extent of drugged and drug-impaired  driving, federal and state officials we spoke with cited difficulty in defining  drug impairment as a significant challenge to addressing drug-impaired  driving. Compared to alcohol, which is chemically simple and has  relatively predictable effects, defining and identifying impairment due to  drugs is much more complicated due to the large number of available  drugs and their unpredictable side effects. The lack of a definition of drug  impairment, in turn, exacerbates challenges in enforcing drug-impaired  driving laws and informing the public about the dangers of driving under  the influence of drugs.
subsections: section_title: Defining Drug Impairment Is Complex
subsections: section_title: No Clear Link between Drug Concentration and Impairment
paragraphs: Toxicologists in three of seven selected states, officials from NIDA,  SAMSHA, and representatives from SOFT stated that identifying a link  between impairment and drug concentrations in the body, similar to the  0.08 BAC threshold established for alcohol, is complex and, according to  officials from SOFT, possibly infeasible. Alcohol is a chemically simple  molecule that is absorbed and metabolized at a relatively consistent and  predictable rate. In contrast, most drugs are chemically complex  molecules; various drugs are absorbed and eliminated from an  individual’s system at different rates. As a result, impairment does not  necessarily correspond to a specific concentration level in the blood, and  detectable amounts of certain drugs may remain even after impairing  effects wear off. For example, as noted earlier, marijuana can be detected  in a daily marijuana user’s system up to 30 days after using the drug.  Toxicologists in four states and representatives from SOFT stated that, as  a result, a positive drug test does not necessarily indicate impairment.
Additionally, drugs can have varying and unpredictable effects on  individuals. For example, individuals with prescriptions for central nervous  system depressants, such as a prescription sleep aid, can develop a  tolerance which can reduce some of the impairing effects. During the first  few days of taking a prescribed central-nervous-system depressant, a  person can feel sleepy and uncoordinated, but as the body becomes  accustomed to the effects of the drug and tolerance develops, these side  effects begin to disappear. As a result, drug concentrations that would be  impairing for one individual may not be impairing to another. Further,  drivers may combine more than one drug or mix drugs with alcohol, which  can have unpredictable results and cause impairment more quickly than  the same amounts of each substance taken alone. According to literature  we reviewed, when combined, multiple drugs or drugs and alcohol can  have a synergistic effect, rather than a simple additive effect, so each  substance may increase the impairing effects of the others.
section_title: Analyzing Samples for the Large Number of Available Legal and Illegal Drugs Is Time Consuming and Expensive
paragraphs: Drug testing is more time consuming and expensive than testing for  alcohol because rather than the single blood or breath test needed to  determine blood alcohol level, separate tests must be conducted for each  suspected drug class (e.g., pain relievers, antidepressants), and the  required instrumentation is sophisticated and costly. According to  toxicologists from two states and representatives from SOFT, it is more  expensive to test for drugs than alcohol. For instance, one toxicologist  stated that standard equipment for alcohol analysis costs between  $100,000 and $120,000; but equipment needed to test for certain types of  drugs can cost up to $500,000. Additionally, the number of potentially  impairing legal and illegal drugs is large. For example, the NRS tested  drivers for 75 illegal, prescription, and OTC drugs identified as potentially  impairing, and while some medications do not affect or can even improve  driving ability, the FDA has identified eight common classes of  prescription and OTC medications as potentially impairing. In addition,  in 2013, the National Safety Council’s Alcohol, Drugs and Impairment  Division reviewed and recommended a list of 33 drugs that should be  included in the scope of drug testing.
Further, new drugs are continually being developed for both legal and  illegal markets, especially synthetics. For instance, the United Nations  Office on Drugs and Crime reported that in the United States, 51 synthetic  cannabinoids (developed to reproduce the effects of THC/marijuana) and  31 synthetic cathinones (mimicking the effects of amphetamines) were  identified in 2012. According to toxicologists in two states, to pursue  detection of new drugs, even if the molecular structure is only slightly  different from other known drugs, labs need to develop a new testing  methodology and then validate that methodology through extensive  testing on each individual instrument. For example, according to one  toxicologist, developing and validating testing methods for a new drug  recently cost about $31,000. Validation of new methodologies is a  complicated task and requires qualified personnel, time, and money.  Additionally, one toxicologist stated that, to run tests on synthetic  cannabinoids and other synthetics, a standard sample against which to  test must be purchased from either a chemical company or another  source. The entire process is lengthy and expensive.
section_title: Enforcement of Drug- Impaired-Driving Laws Is Challenging
subsections: section_title: Lack of Knowledge among Law Enforcement about Drug Impairment in Drivers
paragraphs: State prosecutors and highway safety office officials in three of the seven  selected states said that there is a lack of knowledge among law  enforcement about drug impairment in drivers. Furthermore, according to  officials from NHTSA, GHSA, and IACP, basic training for officers on  impaired driving enforcement is insufficient for identifying drivers that may  be impaired by drugs. For example, officers may be trained to administer  the Standardized Field Sobriety Test, which focuses on detecting alcohol- impairment in drivers; however, officers may not be trained to recognize  drug impairment. One prosecutor stated that there is a misperception  among some officers who have not received training to identify drug  impairment that a drug-impaired driver should exhibit similar symptoms as  a drunken one; including slurred speech and difficulty maintaining  balance. As a result, officers who are not trained to detect drug  impairment may mistakenly think that a driver is not impaired. See table 3  for a comparison of some of the possible symptoms of alcohol and drug  impairment, which vary depending on the type of drug used.
The time between arrest and collection of a sample for drug testing can  affect the quality of biological evidence, such as blood samples, because  the concentration of drugs in the body is constantly changing. Specifically,  logistical challenges and legal requirements pertaining to evidence  collection can increase the time between arrest and sample collection,  reducing evidence quality. Currently, there is no validated roadside drug- testing device, such as the evidential breath-testing device for alcohol,  which would facilitate faster sample collection. Drug testing can be  conducted from a blood, oral fluid, or urine sample. According to  toxicologists from two states, representatives from SOFT, and literature  we reviewed, blood sample analysis is currently the most accurate  method of detecting recent drug use. Officials in two of the states that we  selected said that it can be time consuming to obtain a search warrant for  a blood sample, because it requires approval by a judge. For example,  officials from a state highway-safety office stated that a DUID arrest can  take 3 to 4 hours if blood is being collected, because arresting officers  must wait for a warrant signed by a judge to conduct the blood test.  Moreover, depending on local requirements and resources, potential  offenders may need to be transported by law enforcement to a hospital or  other location for a phlebotomist or nurse to collect a blood sample,  leading to further delays. As the arresting officer waits to collect the  sample, the drug content in the suspect’s blood can decrease  significantly, resulting in a less accurate measure of the drug content in  the blood at the time of the actual traffic stop.
section_title: Lab Backlogs Can Lead to Difficulties in Enforcement and Prosecution
paragraphs: According to toxicologists in four states, the lack of qualified lab personnel  and testing equipment can contribute to a backlog of samples that need  to be tested for drugs, which can result in long waits for toxicology results.  In five of the states that we selected, officials told us that current lab  backlogs ranged from no backlog to about 2,000 cases (the oldest case  being 2 years old). As a result of a lab backlog, officials in two of the  states that we selected said that a prosecutor may have to move forward  with a drug-impaired driving case without toxicology results due to legal  time constraints for prosecution. Additionally, toxicologists from two states  said that some drug compounds continue to degrade once blood samples  have been collected and may not be detectable in the sample three to six  months after collection, making the evidence less useful or of no use to  prosecutors.
section_title: Public Awareness about Dangers of Drugged Driving Is Limited
paragraphs: State prosecutors, toxicologists, law enforcement and highway-safety  office officials from all of the selected states, as well as NIDA, told us that  they believe that there is a lack of public awareness about the dangers of  driving after using prescription medications and marijuana. According to  prosecutors whom we spoke to in three states, alcohol-impaired driving is  easy for people to understand, because the public has been educated  about the dangers of drunk driving through various campaigns. However,  they noted that people believe there is less danger associated with  prescription medications and, in some cases, marijuana. As a result,  jurors may have a more difficult time understanding the dangers  associated with driving under the influence of prescription medication, for  example, based on their personal experience of taking similar  medications without perceiving they are impaired or having a driving  incident. Additionally, according to state prosecutors, toxicologists and  law-enforcement and highway-safety office officials from all of the  selected states as well as NIDA, the public perceives that driving after  using marijuana is not dangerous. Moreover, officials from two state  highway safety offices and NIDA stated that in their view, the public is  generally unaware of the unpredictable effects of combining multiple  drugs. As a result of this perceived lack of awareness, members of the  public may risk unknowingly driving while impaired, potentially leading to  vehicle collisions, injuries, and fatalities.
Officials in four states said that there is a lack of focus on drug  impairment in highway-safety public-education campaigns. For example,  the traffic-safety-marketing communications resources available on  NHTSA’s website for states, partner organizations, and highway safety  professionals who are related to impaired driving are generally focused  on reducing drunk driving: “Drive Sober or Get Pulled Over” and “Buzzed  Driving is Drunk Driving.” See figure 1. Additionally, campaigns in the  states we selected generally use language that may suggest a focus on  impairment due to alcohol, rather than drugs, for example, “Drive  Hammered, Get Nailed.”
section_title: Federal and State Agencies Are Working to Address Drug- Impaired Driving, but NHTSA’s Efforts to Improve Public Awareness Have Been Limited
paragraphs: Federal and selected state agencies are taking actions to address drug- impaired driving, including the challenges previously cited. These actions  include improvements in the areas of research and data, education of law  enforcement and court personnel, evidence quality, legal remedies, and  public awareness. Furthermore, NHTSA, ONDCP, and states have  coordinated their efforts to address drug-impaired driving challenges.  However, NHTSA’s current public awareness initiatives do not clearly  include drug-impaired driving and state officials we spoke with stated that  NHTSA could do more to increase public awareness about the dangers of  drugged driving.
subsections: section_title: Research and Data on Drug-Impaired Driving
paragraphs: Research on Drug Impairment: Federal agencies have completed and are  conducting research to increase knowledge about the relationship  between drugs, impairment, and crash risk. For example, NHTSA is  currently researching the crash risk of drug and alcohol use (including  illegal, prescription, and OTC drugs) by collecting samples from more  than 10,000 crash- and non crash-involved drivers in one city for 20  months. The results of this study are expected in 2015. Additionally,  components of HHS, including NIDA, have researched the impairing  effects of various drugs, including the effects of habitual marijuana use.  For example, NIDA has conducted research on the length of time  marijuana can be detected in blood after use (up to about 30 days in daily  users). Regarding prescription and OTC drugs, the FDA uses information  from studies conducted by drug manufacturers to assess new  medications for adverse effects, including drowsiness, and requires that  those effects are appropriately discussed in labeling, including package  inserts.
Data Availability, Consistency, and Timeliness: To increase the  availability of data on drug-impaired driving, NHTSA has recommended  that states distinguish among alcohol or drugs, or both for impaired  driving cases. Some states, including Colorado and Arizona, are  implementing systems to track whether impaired-driving arrests involved  drugs or alcohol, or both. NHTSA officials stated that such state efforts  may also help improve federal data sources, such as FARS. Additionally,  California, Hawaii, and New York have separated driving under the  influence of alcohol, drugs, or the combined influence of drugs and  alcohol in their impaired driving statutes, a move that may result in more  detailed data on the extent of drug-impaired and alcohol-impaired driving.
In 2013, the National Safety Council’s Alcohol, Drugs and Impairment  Division reviewed and updated a set of minimum recommendations to  toxicologists for drug testing in suspected impaired-driving cases and fatal  crashes, including recommendations to improve the consistency of data  on the frequency with which specific drugs are linked with impaired   Specifically, the recommendations included standards for the  driving.type of sample tested (blood, oral fluid, or urine), the scope of drugs for  which to test, and cutoff values for reporting the presence of a drug. The  NTSB has recommended that NHTSA develop and disseminate similar  standards to state officials. According to NHTSA officials, they have  discussed these types of standards with officials from SAMHSA, NTSB,  and ONDCP. SAMHSA has recently developed oral fluid drug-testing  standards for federal workplaces. These standards are currently under  review and have not yet been released for public comment. NHTSA  officials stated that they plan to wait until these workplace standards are  further along in the approval process in order to develop guidance for  states that are generally consistent with SAMHSA’s workplace standards.
Further, some states have initiated or implemented plans to increase the  capability of toxicology labs to improve the timeliness and availability of  data. For example, Kansas has made recent efforts to increase the  capacity of its forensic lab, housed in the Kansas Bureau of Investigation,  through increased funding to retain specialized technicians, increased  toxicology staffing, and building a new facility. According to an official  from the lab, the improvements should help the state decrease its backlog  of 2,000 toxicology cases (as of August 2014). Additionally, according to  a lab official, the Ohio Crime Lab received federal grant funding in 2013 to  purchase needed instrumentation and coordinates with the Indiana  Department of Toxicology and the Kentucky State Police Toxicology  Laboratories to share information and validation techniques for new drug-  testing methodologies.
section_title: Education for Law Enforcement Officers and Legal Professionals
paragraphs: Drug Recognition Expert Program: One strategy for increasing knowledge  about drug impairment among law enforcement mentioned by officials in  all seven selected states is the Drug Recognition Expert (DRE) program,  which provides training to law enforcement officers and others to identify  drivers under the influence of drugs. For this program, IACP and NHTSA  coordinated to leverage training originally developed in California. The  training includes 72 hours of classroom training and between 40 and 60  hours of field training. Law enforcement officers who complete this  training are certified by states as Drug Recognition Experts (DRE) and  qualified to perform a 12-step evaluation protocol to assess subjects for  drug impairment, which includes psychophysical tests and physical  examinations.
According to IACP’s 2013 annual report on the DRE program, as of  December 2013, about 6,750 DREs have been certified in all 50 states  and the District of Columbia. said that the DRE program was effective, some also discussed  challenges related to the program, including:   While officials in all of the selected states
Training is time-consuming and expensive: Beyond the cost for  training, which is often covered through state and federal grants,  departments may need to pay for travel and lodging costs as well as  overtime pay and additional coverage while officers attend training.
Retention of certified officers: Officials from three selected states as  well as IACP told us that high attrition among DREs makes it difficult  to maintain enough certified officers. Reasons cited for this attrition  include: o  DRE-certified officers tend to be high-performing officers and are  quickly promoted out of traffic units.
International Association of Chiefs of Police, The 2013 Annual Report of the IACP Drug  Recognition Section (Alexandria, VA: Oct. 20, 2014). o  DRE re-certification requirements are time-consuming and  expensive and may be difficult for small departments to fulfill.
NHTSA’s database of DRE reports is difficult to use: NHTSA  maintains a database of DRE reports (submitted voluntarily by DRE  officers) as a source of data on the program and drug-impaired  driving. However, according to law enforcement officials from four of  seven selected states, the DRE database is difficult to use, and the  data are not currently available in a format that allows tracking of  evaluations conducted by individual officers or departments. For  example, officers from two states said that they have trouble  accessing the system. They noted that, as such, some officers do not  report evaluations, making the database incomplete. According to  NHTSA officials, they periodically provide system improvements to  make the database easier and more effective for officers to use; for  example, they are currently determining what identifying information  may be added to the system to make tracking easier, without  compromising privacy or security. Additionally, NHTSA has plans to  improve the system interface and software.
We were not able to identify any comprehensive study on the  effectiveness of the program through our literature review, but NHTSA is  currently conducting a study of a sample of DRE reports to examine the  predictive validity of each of the components of the DRE evaluation; the  results are expected in early 2015.
Advanced Roadside Impaired Driving Enforcement Program: In addition  to the DRE program, law enforcement agencies in all seven of the states  we selected have implemented Advanced Roadside Impaired Driving  Enforcement (ARIDE) training, which is meant to bridge the gap between  the basic training on impaired driving provided in most police academies  and the more intensive DRE program. The 16-hour ARIDE training  program, developed through coordination between NHTSA, IACP, and  the Virginia Association of Chiefs of Police, trains officers to identify and  assess drivers suspected of being under the influence of drugs.  Additionally, ONDCP, NHTSA, and IACP have coordinated to create an  online version of the ARIDE class, which could improve access to drug  impairment evaluation training to law enforcement agencies with more  limited resources. However, officials from five of the seven states said  that they do not allow their officers to take the online version of the ARIDE  class because, in their view, it is not a good substitute for the classroom  training. NHTSA is currently conducting an evaluation of the ARIDE  program, including a comparison of the original training with the online  version, with an expected reporting date of early 2016.
Education for legal professionals: To increase the chances of successful  prosecution of drug-impaired drivers, NHTSA grant funding may be used  for state and regional level Traffic Safety Resource Prosecutor (TSRP)  and Judicial Outreach Liaison (JOL) positions to provide training,  education, and technical assistance to state prosecutors, judges, law  enforcement officials, and toxicologists. For example, TSRPs in Arizona  and California train toxicologists on providing effective testimony during  trials. TSRPs also provide technical support to state and local prosecutors  both generally and on a case-by-case basis to increase local ability to  convict impaired drivers.
Guidance: Federal Agencies including NHTSA and DOJ have provided  states with guidance regarding the enforcement of drug-impaired driving  laws. For instance, DOJ’s Community Oriented Policing Services  component issued guidance on drug-impaired driving as part of its  Problem-Specific Guides series. The guide includes a general description  of drug-impaired driving and its causes as well as strategies to address  enforcement challenges (many described above) and considerations for  implementing the strategies described. Similarly, NHTSA published  Saturation Patrols and Sobriety Checkpoints Guide: A How-to Guide for  Planning and Publicizing Impaired Driving Enforcement Efforts, which  guides state and local law enforcement agencies in planning and  conducting high visibility enforcement campaigns (discussed below).
section_title: Actions to Preserve Evidence Quality
paragraphs: To improve the likelihood that drug testing results will accurately reflect  drug concentrations at the time of a traffic stop or crash, some states  have taken actions to reduce the time between initial contact with law  enforcement and collection of evidence.
Roadside testing: Development of an accurate roadside drug-testing  device, comparable to breath sensors for alcohol detection could  increase law enforcement officers’ ability to identify drivers who have  used drugs. Oral-fluid testing devices that are currently available test  for a limited scope of drugs; representatives from SOFT stated that  the scope includes the most common drugs found in drivers. NIH has  conducted studies to validate the results of oral fluid and breath  testing devices for certain drugs in controlled settings. Further,  NHTSA is currently conducting research on the feasibility of  incorporating available roadside oral fluid-testing devices in criminal  justice processes, with results expected by early 2016. Additionally, a  pilot program using various roadside oral fluid-testing devices has  been conducted in Miami, with varying results depending on the  device and type of drug. For example, one device was more accurate  than the other overall, and accuracy for certain drugs was higher than  for others.
Electronic warrant systems: Washington and Arizona have  established or are in the process of establishing electronic warrant  systems, through which applications for warrants to collect biological  samples are submitted, reviewed, and either granted or denied via  electronic means (telephone, fax, or e-mail). According to law  enforcement officials in those states, these systems can decrease the  time between arrest and collection of samples for drug testing, in an  effort to preserve evidence quality Increased access to phlebotomy services: For the past 8 to 9  years, Arizona has been training law enforcement officers as  phlebotomists to reduce the time between arrest and collection of  samples for drug testing, thus preserving evidence quality.
section_title: Legal Remedies
paragraphs: Sentencing policies: Officials from state agencies in four of seven states  said that sentencing strategies such as the use of impaired-driving courts  reduce recidivism through programs that use a model of post-conviction  supervision and treatment, combined with punishment such as fines, in  order to change behavior. We have previously reported that participants  that received such additional supervision and treatment through adult  drug courts, including designated impaired driving courts, were generally  less likely to be re-arrested than comparison group members drawn from  the criminal court system.
Zero-tolerance per se laws: ONDCP, GHSA, and others have  recommended that states establish “zero tolerance” laws, which make it  illegal per se (in itself) to drive with a detectable amount of a prohibited  drug (defined by state law) in one’s system, regardless of whether there is  evidence of impairment. According to a 2010 NHTSA report on the  effectiveness of such laws, the compelling argument for zero tolerance  laws is that, in their absence, a driver under the influence of an illegal  substance was less likely to be prosecuted for impaired driving than a  driver under the influence of alcohol. This problem existed because a  maximum threshold linked to impairment has been established for  alcohol, but there is no practical way to establish such a level for drugs.  This study found some anecdotal support that zero tolerance laws  increased prosecution rates, but a lack of reliable data prevented NHTSA  from conclusively determining the effectiveness of such laws. Further,  officials from NTSB stated there is no evidence that zero tolerance laws  reduce impaired driving (since a driver need not be impaired to be  prosecuted under the law). As of December 2014, 15 states have enacted  laws that prohibit driving with a detectable prohibited substance in the  driver’s body, without any other evidence of impairment. For example,  Illinois prohibits drivers from having a detectable amount of any illegal  substance or other prohibited substances listed in the statute in his or her  system, which would include certain medications such as hyoscyamine,  which is used to control symptoms associated with gastrointestinal  disorders. See figure 2.
Per se laws/drug concentration limits: Some officials recommend  establishing “per se” limits, or thresholds, for certain drugs, similar to the  0.08 BAC limit established for alcohol. These laws make it illegal per se  (in itself) for a driver to have a specific amount of a certain drug in his/her  blood, oral fluid, or urine regardless of detectable impairment. As of  December 2014, six states have enacted per se laws based on drug  concentration limits for one or more drugs (see fig. 2). For instance,  Washington has established a limit of 5 nanograms of THC per milliliter of  blood for drivers. Colorado has implemented a similar law establishing 5  nanograms of THC per milliliter of blood as a “permissible inference,”  which, according to a state official, means jurors may infer that the  defendant was impaired but are not required to do so. Additionally,  Nevada and Ohio have developed per se thresholds for certain controlled  substances including illegal drugs such as cocaine and heroin as well as  legal drugs such as amphetamines, which can be used to treat conditions  such as attention deficit disorder and narcolepsy.
Per se laws based on drug concentration limits may increase  prosecutions for drivers who are over the established limits, but the  effectiveness of these laws is unknown and may have unintended  consequences. Officials from Colorado, Ohio, and SOFT stated that per  se limits make prosecution of drivers who are over the limits more likely.  However, others, including officials from California and Washington,  stated that it may also make prosecution of drivers who were observed to  be impaired but whose drug test results were under the established limit  more difficult: once thresholds are established, drivers and jurors may  develop the false assumption that driving below the established limit is  legal, even if there is observable impairment. Some toxicologists,  including representatives from SOFT, stated that per se laws based on  thresholds may serve a particular policy goal of increasing prosecutions,  but that a link between the established thresholds and impairment levels  cannot be supported scientifically. A representative from SOFT also  stated that, because illegal drugs generally have no medical purpose,  there is a significant difference between establishing per se threshold  levels for illegal drugs versus per se threshold levels for prescription and  OTC medications. According to the representative, setting per se limits for  prescription and OTC medications may cause problems for those who are  taking medications as prescribed and may not be impaired.
section_title: Efforts to Increase Public Awareness about DUID
paragraphs: Some federal and selected state agencies have implemented drug- impaired driving awareness campaigns to increase public knowledge  about the dangers of drugged driving. For instance, ONDCP developed  the Teen Drugged Driving: Parent, Coalition, and Community Group  Activity Guide, which provides coalitions, prevention groups, and parent  organizations with facts on the dangers and extent of teen and young  adult drugged driving, parent and community activities for effective  prevention, and resources to further assist in prevention activities. At the  state level, Colorado, Washington, and Ohio have conducted public  awareness campaigns focused on drug-impaired driving. For example,  Colorado has aired a series of public service announcements focusing on  the dangers of driving after using marijuana and emphasizing that driving  impaired remains illegal, even as marijuana has been legalized at the  state level.
While NHTSA has also established impaired-driving public awareness  programs, materials associated with these programs do not explicitly  include information on the dangers of drug-impaired driving. NHTSA’s  public awareness programs include high-visibility enforcement campaigns  such as the “Drive Sober or Get Pulled Over” and “Buzzed Driving is  Drunk Driving” campaigns (see fig. 1, presented previously), which  according to NHTSA officials, include drug-impaired driving. For these  campaigns, NHTSA provides media, such as television and radio  advertisements, to states to help inform the public about the dangers of  impaired driving and provides grant funding for state and local police to  perform highly visible checkpoints and patrols to reinforce the concept  that impaired drivers are at a high risk of being caught and prosecuted.  However, using the terms “sober” and “drunk” in the campaign slogans  may indicate that the campaigns are about the dangers of driving after  consuming alcohol as opposed to drugs.
NHTSA’s mission is to support state traffic safety efforts. However,  officials from six of seven selected states as well as representatives from  GHSA stated that public education more explicitly focused on the dangers  of drugged driving is needed, particularly on impairment due to  prescription and OTC medications and marijuana. Officials from some  states recommended actions such as increased education and  requirements for medical professionals regarding prescription drug use  and drug-impaired driving, but also recommended that NHTSA expand  the current messaging on impairment to include the dangers of marijuana  and prescription drugs, which are not explicitly addressed through  NHTSA’s impaired driving advertising campaigns.
According to NHTSA officials, the current lack of data on impairment  thresholds and the broad range of drug effects make it more difficult to  concisely communicate the dangers of drug-impaired driving compared to  alcohol-impaired driving and has prevented them from including drugs  more explicitly in current messaging. However, the messaging for current  alcohol-impaired driving campaigns—such as Drive Sober or Get Pulled  Over—does not specifically allude to the .08 BAC limit. Increased focus  on information about the potential dangers of driving after using drugs  could provide an important reminder to drivers that alcohol is not the only  substance that may impair driving ability. Adding more explicit messaging  about drug-impaired driving could be relatively simple, and could  potentially reduce crashes and associated injuries and fatalities.
NHTSA officials also said they have other plans to improve public  awareness about the dangers of drug-impaired driving. For example,  NHTSA officials plan to conduct a recurring survey of driver attitudes and  behaviors regarding drugged and drug-impaired driving. Data from this  survey could help NHTSA more fully understand any gaps in public  awareness about the dangers of drug-impaired driving and develop  appropriate public awareness campaigns to address those gaps. NHTSA  officials also plan to provide training for physicians and other medical  professionals on how to inform patients about the dangers of driving after  taking some prescription and OTC medications. These efforts to improve  public awareness are in the initial planning stages and could take several  years to implement.
section_title: Coordination among Federal and State Agencies
paragraphs: To leverage the expertise of various stakeholders to address drug- impaired driving, federal agencies—including NHTSA, ONDCP, HHS,  NTSB, and states—have coordinated to identify strategies to address  drug-impaired driving. For instance, ONDCP and NHTSA convened a  roundtable of drug testing and criminal justice experts to examine new  drug testing technology in 2012, and have since coordinated to initiate the  additional research and testing of roadside oral-fluid-testing devices  previously discussed. Additionally, Colorado and Washington have  established impaired-driving working groups to develop and implement  strategies for addressing drug- and alcohol-impaired driving. These  working groups include state and local law-enforcement, traffic-safety,  public-health, and motor-vehicle agencies as well as representatives from  the court system, professional organizations, the marijuana industry, and  others.
section_title: Conclusions
paragraphs: The lack of complete and reliable data on the extent and nature of drug- impaired driving presents federal, state, and local agencies with  challenges to developing and implementing effective countermeasures.  Ongoing and planned activities by NHTSA, ONDCP, and others are  intended to increase available information on drug-impaired driving and  strategies to address the problem, and coordination across the various  federal, state, and local stakeholders is essential to fully implement any  strategy. For example, development and validation of a roadside oral- fluid-testing device may improve evidence collection processes for local  and state law enforcement, but continued efforts to standardize lab  procedures, collect and maintain data, educate law enforcement to  recognize potential drug impairment, and educate prosecutors are also  important to realize the benefits of faster evidence collection.
Despite limited data and the challenge of defining impairment, federal and  state agencies have identified and implemented promising activities— such as the DRE Program, initiatives to reduce the time to collect and  analyze evidence, and public awareness—to combat drug-impaired  driving and associated crashes, fatalities, and injuries. For example, the  DRE Program and high-visibility enforcement campaigns have already  been implemented in many jurisdictions. NHTSA and other federal  agencies have initiated, supported, and continue to improve these  activities. However, state officials consistently noted that their public  awareness efforts would benefit from additional support from NHTSA to  help increase public knowledge of the potential dangers of drug-impaired  driving, including impairment due to some prescription medications and  marijuana. While NHTSA’s plans to improve public awareness of drug- impaired driving through a survey on public behaviors and attitudes and  training for medical professionals are promising, these initiatives will take  time to implement. Additional efforts, such as general messaging  reminding the public about the impairing effects of some drugs and the  dangers of driving after using drugs, could help improve public awareness  in the near term.
section_title: Recommendation
paragraphs: We recommend that the Secretary of Transportation direct the  Administrator of NHTSA to identify actions—in addition to the agency’s  currently planned efforts—to support state efforts to increase public  awareness of the dangers of drug-impaired driving. This effort should be  undertaken in consultation with ONDCP, HHS, state highway-safety  offices, and other interested parties as needed.
section_title: Agency Comments
paragraphs: We provided a draft of this report to DOT, ONDCP, and HHS for review  and comment. In written comments (reproduced in appendix II), DOT  agreed with our findings and recommendation.  ONDCP had no  comments. HHS provided technical comments, which we incorporated as  appropriate.
We are sending copies of this report to the Secretary of Transportation,  the Director of the White House’s Office of National Drug Control Policy,  the Secretary of Health and Human Services, interested congressional  committees, and other interested parties. The report also is available at  no charge on GAO’s Web site at http://www.gao.gov.
If you or your staff have any questions concerning this report, please  contact me at (202) 512-2834 or FlemingS@gao.gov. Contact points for  our Offices of Congressional Relations and Public Affairs may be found  on the last page of this report. GAO staff who made key contributions to  this report are listed in appendix III.
section_title: Appendix I: Objectives, Scope, and Methodology
paragraphs: The Senate Report accompanying the Transportation and Housing and  Urban Development, and Related Agencies Appropriations Bill, 2014  requires us to conduct a study on the strategies that NHTSA, ONDCP,  and states have taken to address drug impairment and assess the  challenges they face in detecting and reducing drug-impaired driving.  Pursuant to that mandate, we reviewed the actions of relevant federal  agencies and selected states as well as relevant literature to identify  actions taken to address drug-impaired driving and associated  challenges. Specifically, we analyzed (1) what is known about the extent  of drug-impaired driving in the United States; (2) what challenges, if any,  exist for federal, state, and local agencies in addressing drug-impaired  driving; and (3) what actions federal and state agencies have taken to  address drug-impaired driving and what gaps exist, if any, in the federal  response to drug-impaired driving. This review defines drug-impaired  driving as driving while impaired by illegal drugs or prescription and over- the-counter (legal) medications. This review does not include impaired  driving among commercial motor carriers, for which different laws and  regulations apply than for members of the general public.
To describe what is known about the extent of drug-impaired driving in  the United States, to identify challenges to addressing drug-impaired  driving, and to identify actions federal and state agencies have taken to  mitigate those challenges, we conducted a literature search to identify  sources of data on the extent of drugged and drug-impaired driving in the  United States and studies on the issue of drug-impaired driving, including  challenges and strategies for addressing the problem. We identified  existing studies from peer-reviewed journals, government reports, and  conference papers based on searches of various databases, such as  ProQuest and Transportation Research International Documentation.  Search parameters included international studies, studies across the U.S.  and in specific states, and research on drug-impaired-driving challenges  and countermeasures. These parameters resulted in 394 abstracts, which  we narrowed to 225 by eliminating, for example, studies addressing only  the extent of drugged or drug-impaired driving in countries other than the  United States or studies on the broader topic of drug abuse. We further  divided the literature into studies on the extent of drugged or drug- impaired driving in the United States and studies on drug-impaired driving  challenges and countermeasures. Studies including data on the extent of  drugged or drug-impaired driving in the United States were reviewed to  identify the source of the data and limitations. We reviewed these studies  and determined that they were sufficiently reliable for the purposes of this  report. Studies on countermeasures to address drug-impaired driving and  challenges were used to provide additional context and information when  needed. We also reviewed state laws to develop information regarding  state zero-tolerance per se laws and state per se laws based on drug  concentration limits.
Additionally, we reviewed documentation, such as research studies and  plans and agency guidance, and interviewed officials from relevant  governmental and non-governmental organizations to identify (1) sources  of data and their limitations, (2) challenges to addressing drug-impaired  driving, and (3) actions taken by federal and state agencies to address  drug-impaired driving as well as gaps in the federal response. Federal  agencies, advocacy organizations, and professional organizations were  chosen based on having a mission relevant to the issue of drug-impaired  driving and recommendations from relevant stakeholders. We interviewed  officials at relevant federal agencies including the National Highway  Traffic Safety Administration (NHTSA); the White House’s Office of  National Drug Control Policy (ONDCP); National Transportation Safety  Board (NTSB); and Department of Health and Human Services’ (HHS)  components including the Substance Abuse and Mental Health Services  Administration (SAMHSA), Centers for Disease Control and Prevention  (CDC), Food and Drug Administration (FDA), and National Institutes of   Additionally, we reviewed documentation obtained from  Health (NIH).and interviewed officials in seven states: Arizona, California, Colorado,  Kansas, Ohio, Vermont, and Washington. We reviewed documentation  and interviewed officials at state agencies responsible for highway-safety  and drug-impairment programs, advocacy organizations, and professional  organizations based on recommendations from the state highway-safety  office. For example, we interviewed officials from state highway-safety  offices, departments of public health and motor vehicles, state law-  enforcement agencies, Drug Recognition Expert (DRE) program  coordinators, state Traffic Safety Resource Prosecutors (TSRP),  associations of police chiefs and district attorneys, state and local  toxicologists, and local interest groups. We selected these states based  on recommendations from federal officials and representatives from  advocacy and professional organizations and to represent a variety of  laws, programs, and other factors. Our selection included:  states with legalized recreational marijuana, states that geographically border states in which recreational  marijuana use has been legalized, states with legalized medical marijuana,  states representing a variety of drug-impaired driving laws, and states identified as having robust programs dealing with driving under  the influence of drugs.
We also reviewed documentation and interviewed representatives from  advocacy and professional organizations including the Governors  Highway Safety Association (GHSA), National District Attorneys  Association, Society of Forensic Toxicologists, Inc. (SOFT), Mothers  Against Drunk Driving (MADD), International Association of Chiefs of  Police (IACP), Insurance Institute for Highway Safety, and National  Council of State Legislatures (NCSL).
We conducted this performance audit from April 2014 through February  2015 in accordance with generally accepted government auditing  standards. Those standards require that we plan and perform the audit to  obtain sufficient, appropriate evidence to provide a reasonable basis for  our findings and conclusions based on our audit objectives. We believe  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.
section_title: Appendix II: Comments from the Department of Transportation
section_title: Appendix III: GAO Contact and Staff Acknowledgments
subsections: section_title: GAO Contact
section_title: Acknowledgments
paragraphs: In addition to the contact above, Sara Vermillion (Assistant Director), Ria  Bailey-Galvis, Melissa Bodeau, D. Kyle Fowler, Katie Hamer, Sara Ann  Moessbauer, Cheryl Peterson, and Maria C. Staunton made key  contributions to this report.