National Association of Drug Court Professionals
Robert L. DuPont, M.D., President
Institute for Behavior and Health, Inc.
www.ibhinc.org
www.StopDruggedDriving.org
Qualifications and Disclosures
 1968: Started career in District of Columbia Department of
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Corrections
1970: Founded Narcotics Treatment Administration
1973 to 1977: Second White House Drug Chief
1973 to 1978: Founding Director, National Institute on Drug
Abuse
1978 to Present: President, Institute for Behavior and
Health, Inc.
1980 to Present: Clinical Professor of Psychiatry,
Georgetown Medical School
1982 to Present: Co-founder and Executive Vice President,
Bensinger, DuPont & Associates; Chairman, Prescription
Drug Research Center (subsidiary of BDA)
Presentation Today
 Introduction to drugged driving
 Prevalence of the drugged driving problem
 National policy efforts to reduce drugged driving
 Defining a drugged driving violation
 Drug testing needs
 Linking drugged drivers to treatment
 Next steps for drugged driving
The Problem
 Drugged Driving refers to operating a vehicle after
the use of impairing substances which may include:
 Illegal drugs
 Misused prescription drugs (with and without
prescriptions)
 Over-the-counter medications
 Other chemicals (e.g. inhaling aerosol spray)
 Drug Court participants, as well as returning veterans,
many of whom face co-occurring diagnoses and addiction
issues, are prime candidates for arrests for drugged driving
A Growing National Focus
 Drugged driving is an under-recognized highway
safety problem, particularly among the public
 Dedicated leadership has elevated drugged driving to
the national stage in the United States, including the
Office of National Drug Control Policy and National
Highway Traffic Safety Administration
Turning Points
 December 2009 release of data from the 2007 National
Roadside Survey
 2010 National Drug Control Strategy identified reducing
drugged driving by 10% by 2015 as a national priority;
reaffirmed in 2011 and 2012 in the National Strategy
 The National Institute on Drug Abuse has led by
promoting a new generation of policy-relevant drugged
driving research
 NIDA’s 2011 Drugged Driving Research: A White Paper
 Leadership from National Association of Drug Court
Professionals (NADCP), National Transportation Safety
Board (NTSB), and Mothers Against Drunk Driving
(MADD)
(ONDCP 2010; 2011a; 2011b; 2012)
Drugs Impair Driving
 Examples of the dangerous effects of drugs on driving
include:
 Disorientation, poor judgment/decision-making,
changes in reaction time, distance estimation,
concentration, impulse control
 Many factors influence the effects of a drug on a driver
and can be enhanced by drug-drug interactions,
including alcohol
 Drug use triples the risk of fatal crash; a combination
of drugs and alcohol produces 23 times the risk of fatal
crash
(Couper & Logan, 2004; Li, Brady & Chen, 2013)
Drugged Driving Research
 Decades of research on alcohol and driving, now with
other drugs
 Significant prevalence of drugs among driver
populations:
 National surveys (self-report and random stops)
 Impaired driving (DUI) suspects
 Seriously injured drivers
 Fatally injured drivers
 There is much more research than the studies
reviewed in this presentation
(DuPont, et al., 2011)
Driving Under the Influence
 29.1 million (11.2%) drivers aged 12 and older report
that they drove under the influence of alcohol in the
previous year
 10.3 million (3.9%) report driving under the influence
of illicit drugs
 But among randomly stopped drivers, impaired
driving suspects, and seriously and fatally injured
drivers, we see that drugged driving is roughly equal
to the problem of drunk driving
(SAMHSA, 2013)
National Roadside Survey: Drug Use
Among Weekend Nighttime Drivers
 16.3% of drivers were
positive for potentially
impairing drugs
 Most common illegal drugs:
 Cannabis, 8.6%
 Cocaine, 3.9%
 Methamphetamine, 1.3%
(Lacey, et al., 2009)
NRS: Alcohol Use Among Weekend
Nighttime Drivers
 12.4% of drivers
were alcoholpositive
 Illegal Blood
Alcohol
Concentrations
(BAC) of 0.08 g/dL
or higher steadily
decreased during
this time
(Compton & Berning, 2009)
Crash-Involved Drivers Taken to
Shock-Trauma
 Half were positive for
illegal drugs
 One third positive for
alcohol
 One quarter positive for
both illegal drug(s) and
alcohol
 One quarter positive for
marijuana; 39% of
marijuana-positive drivers
were also positive for
another drug
(Walsh, et al., 2005)
Impaired Driving Suspects
 A US study of impaired driving suspects showed that
 31% positive for drugs
 86% positive for alcohol
 25% positive for both
 51% of drivers with BACs below 0.08 were drug-
positive
 22% of drivers with illegal BACs were drug-positive
(Buchan, et al., 1998; Fix, et al., 1997)
Fatally Injured Drivers
 Research shows that the while the prevalence of
alcohol among fatally injured drivers decreased from
2005 to 2009, the prevalence of drugs among dead
drivers increased 18%
 In 2009, one third (33%) of all fatally injured drivers in
the U.S. who had confirmed drug test results
(n=12,055) were drug-positive
 28% of drug-positive drivers tested positive for
marijuana
(NHTSA, 2010)
Drug Prevalence Among Fatally Injured
Drivers Has Increased, 2005-2009
34%
33%
33%
32%
31%
30%
30%
29%
28%
28%
28%
2005 (n=12,324)
2006 (n=14,325)
2007 (n=14,893)
28%
27%
26%
25%
2008 (n=14,381)
2009 (n=12,055)
(Center for Substance Abuse Research, 2010)
Fatally Injured Drivers
 With national fatally injured driver data we are only
seeing a part of the picture
 Only 20 states test at least 80% of fatally injured
drivers for drugs
 Testing procedures and panels are not standardized
 Some states do not test for marijuana
 Research has shown that drug-involved crashes occur
throughout the day while alcohol crashes are more
common at night
(Romano & Pollini, 2013)
Fatally Injured Drivers
 In a study of fatally injured drivers in Washington
State (n=370), 39% were positive for drugs
 12.7% were positive for marijuana
 41% of all drivers were positive for alcohol
 Of all alcohol-positive cases, 42% were also
positive for one or more drug showing the overlap
in drug and alcohol use among drivers
(Schwilke, Sampaio dos Santos, & Logan, 2006)
Drugged Driving Policy and
Demand Reduction
 Strong, effective drugged driving laws and
comprehensive enforcement are crucial elements of
improved demand reduction
 Reducing drugged driving is part of the solution to:
1) Prevent illegal drug use
2) Promote highway safety
3) Deliver substance abusers to treatment with the
leverage to help them become and stay drug-free
Drugged Driving Laws
Per se drug laws
2) Impairment laws
3) Administrative license revocation (ALR)
1)
 Drugged driving laws cannot follow same path as
alcohol-impaired driving laws
Alcohol Impairment Standard
 Reducing drugged driving is wrongly based on the
model of 0.08 g/dL BAC
 Obscures the fact that many drivers are significantly impaired
at levels well below 0.08 BAC
 Tolerance and consumption effects vary among alcohol users
displaying widely varying degrees of impairment at 0.08 BAC
or higher
 Though cases are much more difficult to try, impaired drivers
under 0.08 BAC can be prosecuted
 Most Western European countries use 0.05 g/dL limit;
Sweden and Norway use 0.02 g/dL limit
(DuPont, et al., 2013)
Mirage of BAC Equivalent for Drugs
 Alcohol is a poor model for studying impairing effects
of drugs; metabolized in simpler ways than drugs
 No close link between blood or other levels of a drug
(or drug metabolites) and measured impairments
 Vast number of potentially impairing drugs
 Drug-drug, drug-alcohol combinations
 Emergence of synthetic “designer” drugs
(Reisfield, et al., 2012; DuPont, et al., 2013)
Mirage of BAC Equivalent for Drugs
 Role of tolerance in impairment: e.g. methadone
 Consumption of 50 mg of methadone can be lethal to
person who has not used opioids in prior few weeks or
months
 Chronic administration of methadone at stable doses
typically produces no measurable impairment at higher
doses
 Others factors on impairment include time of day,
driver age and driver experience
(Reisfield, et al., 2012; DuPont, et al., 2013)
The Bottom Line
 Setting impairment thresholds based on tissue levels
of drugs or metabolites for illegal drugs is not a viable
enforcement option
 0.08 BAC equivalent is not needed
 We have abundant successful precedents for using the
per se standard for drugs of abuse
(Reisfield, et al., 2012; DuPont, et al., 2013)
Per Se Drug Laws
 Under a per se drug law, any identified illegal drug level
found in a driver is defined as a drugged driving violation
 Modeled on the successful per se drug program used for
the 10 million American commercial drivers and others
in safety-sensitive positions
 In the United States, drivers under age 21 are held to a
zero tolerance per se standard for alcohol
(Walsh, 2009; DuPont, et al., 2012)
The Bright Line of Illegality
 For drivers arrested for impaired driving:
 When the drug use is illegal, the zero tolerance per se
standard is used
 When the drug use is legal (e.g. prescription drug for
which the driver has a valid prescription), the
“impairment” standard is used
(Voas, et al., 2013; DuPont, et al., 2012)
Impairment Laws
 Impairment is a hard case to make without per se
law but it can be done
 Drivers can be prosecuted for impaired driving when
they are under 0.08 BAC alcohol
 Remember that it is illegal to drive impaired with no
alcohol and no drugs
(DuPont, et al., 2012)
Complexity of Marijuana
 This is a political complexity; not a scientific complexity
 A solution:
 When marijuana use is “legal”, use the impairment standard
 When marijuana use is illegal, use the zero tolerance per se
standard
 Caveat: Marijuana is illegal throughout the U.S. under
federal law
 The two wild cards are state-based “medical marijuana”
and legal marijuana in Colorado and Washington which
will have to be settled by the U.S. Supreme Court
Policy Focus on Marijuana
 State-based marijuana policy changes have ignited a
renewed focus on finding a BAC equivalent for marijuana
with recommendations between 2 ng/mL and 10 ng/mL
THC in whole blood
 Large study of drivers arrested for impairment in Sweden
over 10 years tested between 30-90 minutes after arrest:
 90% had THC concentrations below 5 ng/mL in blood
 61% had THC concentrations below 2 ng/mL in blood
 43% had THC concentrations below 1 ng/mL in blood
(Jones, Holmgren, & Kugelberg, 2008)
Frequency Distribution of Blood THC
Concentrations Among DUI Suspects
 Under a 5 ng/mL THC
limit for blood, only 10%
of drivers in this study
would have been
prosecuted
(Jones, Holmgren, & Kugelberg, 2008)
Washington and Colorado
 Washington has a 5 ng/ml THC per se limit for blood
 Any driver at or over 5 ng/ml is in violation
 Colorado has a 5 ng/ml permissible inference limit for
blood – weakest drugged driving law for marijuana
 Inference that any driver at or over 5 ng/ml was under the
influence at time of arrest but impairment must be proved
 70% of Colorado drivers arrested for suspicion of driving
under the influence who test positive for active THC test at
less than 5 ng/ml
 Both 5 ng/ml limits – per se and permissible inference
– give free passes for most stoned drivers
(Wood, 2013)
Latest Marijuana Research
 Recent smoking and/or blood THC concentrations of
2-5 ng/mL are associated with substantial driving
impairment
 Epidemiological research suggests that marijuana use
doubles risk of motor vehicle crash
 Whole blood THC concentrations persist multiple
days after drug discontinuation in heavy chronic
marijuana users
 After 3 weeks of abstinence, chronic daily marijuana
users showed observable impairment compared to
occasional marijuana users
(Li, et al 2012; Asbridge, et al. 2012; Hartman & Huestis 2013; Karschner et al. 2009; Bosker et al. 2013)
Role of the Pro-Drug Lobby
 Advocates for permissive drug policies aim to legalize
the use, production and sale of drugs, beginning with
marijuana
 “Medical marijuana” movement has been successful in
shifting the lobby’s goal to full marijuana legalization
 “Psychedelic medicine” is the next candidate for drug
legalization
 Pro-drug lobby opposes driving restrictions on drug
users – particularly against laws related to marijuana
Administrative License Revocation
 Non-criminal penalty system used today to get drunk
drivers off the road quickly
 ALR process begins after arrest for impairment is made
 Loss of license for drivers who test at or above 0.08 BAC
alcohol
 ALR for drugs is the next step in drugged driving
enforcement
 Presumption of innocence is preserved for later
adjudication of criminal charge of DUI or DUID by a
judge
(National Transportation Board, 2013)
Importance of ALR
 ALR is a potential game-changer because it would
bring drug testing to the police station in a way
parallel to alcohol testing
 Use of on-site oral fluid or urine testing
 Loss of license for positive screening drug test results
 Laboratory confirmation of positive tests prior to
adjudication
Typical Testing Procedures
 In the U.S. impairment is determined prior to arrest
 Use of Standardized Field Sobriety Tests (SFSTs)
 Some states use Drug Recognition Experts (DREs)
 Specimen testing typically occurs after arrest
 When illegal BAC is found, testing usually ends and
driver is charged with drunk driving
 If an impaired driver has a low BAC then drug testing
should but does not always occur
Improve Drug Testing Procedures
 Use on-site screening tests for ALL impaired driving
suspects, including those who have illegal BACs
 Testing technology has improved; oral fluid testing
permits easy specimen collection and initial screening
results but today few states permit its use
 Laboratory confirmation
 Address laboratory staff/funding issues
 Drivers who have illegal BACs and test positive for
drugs should be charged with an aggravated offense,
like drivers with high BACs (≥ 0.15 g/dL)
Other Drug Testing Opportunities
 Drivers in crashes causing serious injuries or death,
either at the scene or at the hospital/trauma center
 When drugs have been found in vehicles or on
drivers
 When drivers admit to recent drug use
 Highway security checkpoints
Education, Training & Treatment
 Incorporate drugged driving into drivers’ education and
substance abuse prevention programs
 Educate groups at higher risk about drugged driving, e.g.
Drug Court participants
 Increased training to law enforcement on identifying
drugged drivers
 Screen and refer drugged drivers to treatment and
appropriate monitoring programs to reduce recidivism
DUI Offender Management
 Assess DUI offenders for both alcohol and drug use
problems and other disorders
 Ensure all DUI offenders are tested for alcohol and
drugs
 Close monitoring after conviction using model
programs that stop alcohol and drug use rather than
focusing exclusively on driving behaviors
DWI/Drug Courts
 Manage hardcore repeat impaired driving
offenders
 Leverage criminal justice system to improve longterm outcomes including reduced recidivism
 Focus on accountability and long-term treatment
 Address other issues including mental health
problems
(Fell, et al., 2011; Hiller, et al, 2009; Michigan SCAO, 2008)
DWI/Drug Courts
 Frequent random drug and alcohol testing with
immediate consequences
 Great potential resource to address drugged
drivers
 Consider prominent overlap of drug problems
among alcohol-impaired drivers
(Fell, et al., 2011; Hiller, et al, 2009; Michigan SCAO, 2008)
Education Within DWI/Drug Courts
 Participants in both DWI Courts and Drug Courts
need to be educated about the risks of drugged driving
 Remind them that it is unsafe – and illegal – to drive
under the influence of alcohol and after using drugs
 Place special emphasis on marijuana which many
people do not recognize as a highway safety threat
24/7 Sobriety Program
• Focuses on keeping DUI offenders abstinent from
alcohol and drugs
• Treatment and 12-Step involvement is optional
• Frequent alcohol and drug testing:
• Twice daily alcohol breath tests (7 AM & 7 PM) or
• SCRAM alcohol monitoring ankle bracelets; and
• Random drug urinalysis or
• Drug patch
• Any positive test results in an immediate short-term
stay in jail
(South Dakota Office of the Attorney General, 2013)
24/7 Sobriety Results
 55% never fail a test
 16.7% fail only one test
 12.5% fail only twice
 16.9% fail three or more times
 DUI recidivism substantially lower among 24/7
participants at 1, 2, and 3 years from program
completion
(South Dakota Office of the Attorney General, 2012)
Community Impact
 24/7 Sobriety has helped reduce:
 Repeat drunk driving offenses by 12% at the county level
 Domestic violence by 9%
 Traffic crashes for males between ages 18-40 by 4%
 Frequent random monitoring linked to swift, certain
and meaningful consequences – mostly brief
incarceration – produces fewer failures
(Kilmer, et al., 2013; DuPont, et al., 2010 )
Next Steps for Drugged Driving
 Use of administrative license revocation to get drugged
drivers immediately off the roads and to increase drug
testing of DUI suspects
 Use of the per se standard to effectively identify and
prosecute drugged drivers
 Ongoing research and evaluation of drugged driving
laws and enforcement strategies
 Focus on the management of the 1.2 million people
arrested for DUI each year
Conclusions
 Focusing on drugged driving builds upon and
enhances efforts to reduce drunk driving; they are
synergetic – NOT COMPETITIVE
 The never-ending search for impairment thresholds
derails actions to prevent drugged driving and
enforce laws
Conclusions
 Effective action on drugged driving will achieve 3
important goals:
Reduce illegal drug use and reinforce prevention
2) Improve highway safety
3) Provide an important new pathway to treatment
and recovery for drug users as drunk driving
enforcement now does for individuals with alcohol
use problems
1)
Thank you!
www.StopDruggedDriving.org
 For more information on
drugged driving visit
IBH’s website devoted to
this public health and
public safety problem
www.IBHinc.org
 For more information on
other new and important
ideas to reduce illegal
drug use visit IBH’s home
website
References and Resources
 Asbridge, M., Hayden, J. A., & Cartwright, J. L. (2012). Acute cannabis consumption and
motor vehicle collision risk: systematic review of observational studies and metaanalysis. British Medical Journal, 344, e536.
 Bosker, W.M., Karschner, E.L., Lee, D., Goodwin, R.S., Hirvonen, J., Innis, R.B.,
Theunissen, E.L., Kuypers, K.P., Huestis, M.A., & Ramaekers, J.G. (2013). Psychomotor
Function in Chronic Daily Cannabis Smokers during Sustained Abstinence. PLoS One,
8(1), e53127.
 Center for Substance Abuse Research. (2010, December 20). One-third of fatally injured
drivers with known test results tested positive for at least one drug in 2009. CESAR FAX,
19(4).
 Compton, R., & Berning, A. (2009, July). Results of the 2007 National Roadside Survey of
Alcohol and Drug Use by Drivers. Traffic Safety Facts, Research Note. Washington, DC:
National Highway Traffic Safety Administration, National Center for Statistics and
Analysis.
 Couper, F. J., & Logan, B. K. (2004). Drugs and Human Performance Fact Sheets.
Washington, DC: National Highway Traffic Safety Administration. Available:
http://www.nhtsa.gov/People/injury/research/job185drugs/index.htm
 DuPont, R. L., Logan, B. K., Shea, C. L., Talpins, S. K., & Voas, R. B. (2011). Drugged
Driving Research: A White Paper. Institute for Behavior and Health, Inc. Drugged
Driving Committee. Prepared for the National Institute on Drug Abuse. Available:
http://www.whitehouse.gov/sites/default/files/ondcp/issues-content/druggeddriving/nida_dd_paper.pdf
 DuPont, R. L., Reisfield, G. M., Goldberger, B. A., & Gold, M. S. (2013). The Seductive
Mirage of a 0.08 g/dL BAC Equivalent for Drugged Driving. DATIA Focus, 6(1), 36-43.
 DuPont, R. L., Shea, C. L., Talpins, S. K., & Voas, R. (2010). Leveraging the criminal
justice system to reduce alcohol- and drug-related crime. The Prosecutor, 44(1), 38-42.
 DuPont, R. L., Voas, R. B., Walsh, J. M., Shea, C., Talpins, S. K., & Neil, M. M. (2012). The
need for drugged driving per se laws: A commentary. Traffic Injury Prevention, 13(1), 3142.
 Fell, J. C., Tippetts, A. S., & Langston, E. A. (2011). An Evaluation of Three Georgia DUI
Courts. DOT HS 811 450. Washington, DC: National Highway Traffic Safety
Administration. Available:
http://www.dwicourts.org/sites/default/files/nadcp/Georgia%20Final%20Study.pdf
 Hartman RL, Huestis MA. (2013). Cannabis Effects on Driving Skills. Clinical Chemistry,
59(3), 478-492.
 Hiller, M., Saum, C., Taylor, L., et al., (2009). Waukesha Alcohol Treatment Court
(WATC): Process and Outcomes. Philadelphia, PA: Temple University. Available:
http://www.dwicourts.org/sites/default/files/nadcp/WATC_Outcome_Evaluationfinal%20draft.pdf
 Jones, A.W., Holmgren, A., & Kugelberg, F.C. (2008). Driving under the influence of
cannabis: A 10-year study of age and gender differences in the concentrations of
tetrahydrocannabinol in blood. Addiction, 103(3), 452-461
 Karschner EL, Schwilke EW, Lowe RH, Darwin WD, Pope HG, Herning R, Cadet JL,
Huestis MA. (2009). Do Delta9-tetrahydrocannabinol concentrations indicate recent use
in chronic cannabis users? Addiction, 104(12):2041-8.
 Kilmer, B., Nicosia, N., Heaton, P. & Midgette, G. (2013). Efficacy of frequent monitoring
with swift, certain and modest sanctions for violations: Insights from South Dakota’s
24/7 Sobriety Project. American Journal of Public Health, 103(1), e37-e43.
 Lacey, J. H., Kelley-Baker, T., Furr-Holden, D., Voas, R. B., Romano, E., et al. (2009). 2007
National Roadside Survey of Alcohol and Drug Use by Drivers: Drug Test Results. DOT
HS 811 249. Washington, DC: National Highway Traffic Safety Administration. Available:
http://www.nhtsa.gov/Driving+Safety/Research+&+Evaluation/2007+National+Roadside
+Survey+of+Alcohol+and+Drug+Use+by+Drivers
 Li, G., Brady, J. E., & Chen, Q. (2013). Drug use and fatal motor vehicle crashes: A casecontrol study. Accident; Analysis and Prevention, 60, 205-210.
 Li, M., Brady, J. E., DiMaggio, C. J., Lusardi, A. R., Tzong, K. Y., & Li, G. (2012). Marijuana
use and motor vehicle crashes. Epidemiologic Reviews, 34(1), 65-72.
 Michigan Superior Court Administrative Office & NPC Research. (2008). Michigan DUI
Courts Outcome Evaluation. Lansing, MI: Michigan Superior Court Administrative
Office. Available:
http://www.dwicourts.org/sites/default/files/nadcp/MI%20DUI%20Outcome%20Evalua
tion%20FINAL%20REPORT%20Re-Release%20March%202008_0.pdf
 National Highway Traffic Safety Administration. (2010, November). Drug Involvement of
Fatally Injured Drivers. Traffic Safety Facts. DOT HS 811 415 Washington, DC: NHTSA’s
National Center for Statistics and Analysis. Available: http://wwwnrd.nhtsa.dot.gov/Pubs/811415.pdf
 National Transportation Safety Board. (2013). Reaching Zero: Actions to Eliminate
Alcohol-Impaired Driving. Safety Report NTSB/SR-13/01. Washington, DC: National
Transportation Safety Board. Available:
http://www.ntsb.gov/doclib/reports/2013/SR1301.pdf
 Office of National Drug Control Policy. (2010). National drug control strategy, 2010.
Washington, DC: Office of National Drug Control Policy. Available:
http://www.whitehouse.gov/sites/default/files/ondcp/policy-and-research/ndcs2010.pdf
 Office of National Drug Control Policy. (2011a). National drug control strategy, 2011.
Washington, DC: Office of National Drug Control Policy. Available:
http://www.whitehouse.gov/sites/default/files/ondcp/ndcs2011.pdf
 Office of National Drug Control Policy. (2011b, October 13). White House drug policy
director and Mothers Against Drunk Driving unite to combat drugged driving; call on
parents to act to reduce significant public safety threat. Washington, DC: ONDCP Public
Affairs. Available:
http://www.whitehouse.gov/sites/default/files/ondcp/white_house_drug_policy_directo
r_and_mothers_against_drunk_driving_unite_to_combat_drugged_driving.pdf
 Office of National Drug Control Policy. (2012). National drug control strategy, 2012.
Washington, DC: Office of National Drug Control Policy. Available:
http://www.whitehouse.gov/sites/default/files/ondcp/2012_ndcs.pdf
 Reisfield, G. M., Goldberger, B. A., Gold, M. S., & DuPont, R. L. (2012). The mirage of
impairing drug concentration thresholds: A rationale for zero tolerance per se driving
under the influence of drugs laws. Journal of Analytical Toxicology, 36(5), 353-356.
 Romano, E., & Pollini, R. A. (2013). Patterns of drug use in fatal crashes. Addiction,
108(8), 1428-1438.
 Romano, E., & Voas, R. B. (2011). Drug and alcohol involvement in four types of fatal
crashes. Journal of Studies on Alcohol and Drugs, 72(4), 567-576.
 Schwilke, E. W., Sampaio dos Santos, M. I., & Logan, B. K. (2006). Changing patterns of
drug and alcohol use in fatally injured drivers in Washington State. Journal of Forensic
Science, 51(5), 1191-1198.
 South Dakota Office of the Attorney General. (2013). South Dakota 24/7 Program.
Available: http://apps.sd.gov/atg/dui247/247ppt.pdf (retrieved November 2013
 Substance Abuse and Mental Health Services Administration. (2013). Results from the
2012 National Survey on Drug Use and Health: Summary of National Findings, NSDUH
Series H-46, HHS Publication No. (SMA) 13-4795. Rockville, MD: Substance Abuse and
Mental Health Services Administration.
 Voas, R. B., DuPont, R. L., Shea, C. L., & Talpins, S. K. (2013). Prescription drugs, drugged
driving and per se laws. Injury Prevention, 19(3), 218-221.
 Voas, R. B., DuPont, R. L., Talpins, S. K. & Shea, C. L. (2011). Towards a national model for
managing impaired driving offenders. Addiction, 106(7), 1221-1227.
 Walsh, J. M. (2009). A State-by-State Analysis of Laws Dealing with Driving Under the
Influence of Drugs. Washington, DC: National Highway Traffic Safety Services
Administration. DOT HS 811 236.
 Walsh, J. M., Flegel, R., Atkins, R., Cangianelli, L. A., Cooper, C., Welsh, C., & Kerns, T. J.
(2005). Drug and alcohol use among drivers admitted to a Level-1 trauma center. Accident
Analysis & Prevention, 37(5), 894-901.
 Wood, E. (2013, January 1). Should Colorado adopt a permissible limit for THC? No.
Denver Post. Available: http://www.denverpost.com/opinion/ci_22351390/no-allowing-5ng-limit-thc-lev