How can we tell if a driver is impaired through to drink & drugs?

1. Is my driving impaired?
Dr Richard Evers
Synergy Health Laboratory Services

2. SHLS
Laboratory Services division
of Synergy Health
•Based in Abergavenny, South
Wales
•Established in 1986
•On-site Toxicology, Pathology and
PCR suites

3. Services from SHLS
•Drug and Alcohol screening
• Urine
• Saliva
• Hair
• Breath Alcohol
•Drug and Alcohol sample collection services
•Clinical Pathology testing services
•Training services

4. What do we mean by “Impaired”
• Road Traffic Act (1988) Section 6B
– CODE OF PRACTICE FOR PRELIMINARY
IMPAIRMENT TESTS (DfT 2004)
• Designed to determine of you are unfit to
drive

5. Field Impairment Test
• Pupillary Examination
– Look ahead
– Keep eyes open
– Pupil size
– Rednes or watery

6. Modified Romberg Balance Test
• Stand to attention
– Tilt head back and close eyes
– Return head to upright and open eyes after 30
seconds
– Note balance control and timing

7. Walk and Turn Test
• Stand still on a line
– Nine heel-to-toe steps, turn and nine steps
back, counting out loud
– Correct counting and steps
– Deviation from line

8. One Leg Stand
• Stand still
– Raise right foot 6-8 inches parallel to ground
– Look ahead
– Repeat for left foot
– Record balance

9. Finger to nose test
• Hold both hands out in front with index
fingers extended
– Close eyes
– Touch tip of the nose
– Alternate hands on command
– Record balance, missing nose
or using the wrong hand

10. Drink drive levels
• England and Wales
– Blood 80mg/100mL
– Breath 35µg/100mL
– Urine 107mg/100mL
• Scotland
– Blood 50mg/100mL
– Breath 22µg/100mL
– Urine 67mg/100mL

11. Drink drive stats 2013
• 683,631 tests
– 71,675 positive (10.5%)
• 232,709 accidents (6,524 HGV)
– 53% breathalysed (65% HGV)
– 1.6% positive (0.4% HGV)
• 17% of deaths positive
DfT National Statistics
(www.gov.uk)

12. Drink drive stats – Why test?
• Traffic offense (37%)
– 6% Positive
• Collision (32.7%)
– 8% Positive
• Suspicion (18.7%)
– 18.7% Positive
– 18.9% alcohol present below limit
DfT (www.gov.uk)

13. Drug drive stats
• 1132 convictions for drug driving (2012)
– 19% of surveyed admit to driving while unfit
– 7% due to illegal drugs
• 902 arrests March – May 2015
– 45% of tests positive
– 1 arrest every 2½ days
– 1 test per day
IAM & Daily Mail
FOI requests

14. Is cannabis a problem?
• From US Data

15. Drug drive levels
Drug
Cutoff
(µg/L) Drug
Cutoff
(µg/L)
Amphetamine 250 LSD 1
Benzoylecgonine 50 Methadone 500
Clonazepam 50 Methamphetamine 10
Cocaine 10 Ecstasy 10
Cannabis 2 6-monoacetylmorphine 5
Diazepam 550 Morphine 80
Flunitrazepam 300 Oxazepam 300
Ketamine 20 Temazepam 1000
Lorazepam 100

16. DT5000
• Wide test menu
– Cannabis
– Cocaine
– Opiates
– Benzodiazepines
• Home Office Type Approved
– Cannabis

17. Cannabis
• Legal Limit 2µg/L THC in blood
• Driving Simulator
– Controlled cannabis use
– Measured impairment
• 8µg/L THC gives similar impairment to
0.50‰ Alcohol

18. Long term cannabis use
• Cannabis users confined to a drug free
R&D facility
• Daily blood cannabis levels
• >2µg/L for 18 days

19. hangover
• You do not have to have drugs in your system to
be impaired
• Driving simulator with a hangover gives a similar
level of impairment to BAC 0.40‰
• Longer sleep following drinking leads to less
impairment (!!!)
• “chronic use of all illicit drugs is associated with
some cognitive and/or psychomotor impairment,
and can lead to a decrease in driving
performance even when the subject is no longer
intoxicated” - EMCCDA

20. Amphetamine
• Controlled administration studies
– Amphetamine no more harmful to cause
accident
• Post-accident testing figures
– Amphetamine 6x more likely to cause death
• Amphetamine increases risk taking
• Dexedrine given to fighter pilots

21. San Francisco Bay Bridge, 2007
• M/V Cosco Busan hit the
pier in fog
• 53,500 gallons of fuel oil
spilt
• $3.6 million repair bill
• $70 million environmental
cleanup
• Pilot tested BEFORE
accident and negative for
SAMHSA 5 and alcohol

22. Stimulant/depressant mix
• Pilot was taking:
– Lorazepam
– Diazepam
– Modafinil
– Propoxyphene
– Hydrocodone
– Pentazocine (narcotic analgesic)
• Narcotics & sedatives – send you to sleep
• Modafinil – wakes you up
• Similar patterns of use with amphetamines and benzodiazepines
• Cocaine and heroin

23. Is my driving impaired?
• Alcohol – legal limit
• Drugs – legal limit for some
• Tiredness – limit on driving hours
• Cold / ‘Flu – no law
• Hangover – no law

24. Thank You