Written evidence from Dr Rob Tunbridge
(DDD 36)
Independent Alcohol, Drug Driving and Driver
Impairment Consultant
N.B. The following are strictly my personal
views and mine only.
1. REDUCTION OF
THE PERMITTED
BLOOD ALCOHOL
LIMIT
In my view reduction of the GB Drink Drive limit
is a relatively low priority.
GB currently has nearly the best, if
not the best, drink drive record in the world, as measured by
unbiased BAC levels in driver fatalities.
This is because it is the only jurisdiction,
bar Victoria (Australia), that takes away a drivers licence for
1 year on a 1st offence, irrespective of BAC.
For example, France, like the majority of other
EU countries has a 50mg limit, but does not impose a 1 year ban
until the BAC reaches 200mg.
In GB such a BAC limit warrants a 3 year ban
and medical intervention.
France consequently has a worse drink drive
record than Britain.
It should be remembered that the average drink
driver's BAC is c. 150mg/100 ml in blood! Almost twice the drink
drive limit.
Bringing down the limit would be beneficial,
but only if enforcement levels were maintained and a lower penalty
for a lower drink drive level (below 80) was NOT introduced.
This would give entirely the wrong mixed message
on the seriousness of drink driving.
The current law should be enforced more rigorously
with more breath tests!
In recent years roadside breath tests have dropped
from 800,000 to around 600,000 per year. The introduction of roadside
evidential breath testing would greatly assist this.
Roadside Evidential Breath Testing (As allowed
under the Serious Organised Crime & Police Act 2005) should
be introduced speedily!
There is no excuse for the continued delay in
type approving existing devices which meet all current international
scientific standards and are in daily use in many other countries.
Roadside testing would eliminate the sometimes
substantial delay in obtaining an evidential test at a police
station. A study by Sussex police in 2001 estimated that around
25% of cases were lost due to time delays in testing drivers,
who would have been over the limit at the roadside!
The universal measure of the percentage of drivers
killed in accidents who are over the limit has been clearly shown
to be inversely proportional to the number of tests carried out.
Greater enforcement is a great deterrent.
As stated above, I believe the one year minimum
ban is a good deterrent and should be retained, not weakened by
shorter disqualifications or fines.
Targetted, rather than random, tests should
be introduced. Police generally know where people drink and the
"type" of driver likely to offend.
Targetted checkpoints and testing of Individuals
assisted by ANPR should be introduced.
Police currently have powers to stop for any
reason. If they suspect alcohol they may then test for it. Targeting
drinking locations would improve detection of drink driving.
A lower limit for novice drivers, in my view,
gives the wrong message. It implies once you get more driving
experience you are allowed to drink more!
If a 50 mg limit is brought in it should be
quickly and also apply to professional drivers. Fitting of driver
interlocks should also be considered for this latter group.
2. THE PROBLEM
OF DRUG
DRIVING
At present, information to throw light on the
above is limited. The last time a thorough study was undertaken
into the incidence of drugs in road fatalities (Tunbridge, R.J.
et al. (2001) The Incidence of Drugs and Alcohol in Road Accident
Fatalities. TRL Report 495 available online at www.trl.co.uk/store/report_list.asp)
It was found that 18% of drivers had at least
one illicit drug and 6% had medicinal drugs.
The former had shown a massive increase (from
3%) since the 1980s when a previous study was conducted (TRL,
Research Report 202, 1989). Medicinal drug incidence had remained
unchanged at 6%. These results prompted the DfT to conduct an
extensive programme of research on drug driving in the early 2000's.
Data on non-fatally injured drivers is much
more limited. This is because drug analysis is very expensive
(compared to alcohol testing); in excess of £500 for a screening
and confirmation. It is therefore only carried out when a police
officer has evidence of major impairment, often after a negative
breath test.
DfT figures for 2007 show that drug impairment
was a measured contributory factor in only 685 accidents compared
to 16,585 for alcohol (Road Accidents GB, (2008), DfT). This figure
however by no means gives an accurate assessment as the vast majority
of drivers suspected of impairment are not tested for drugs, especially
if they give a positive roadside breath test.
A new offence of driving with the presence of
a proscribed drug would be greatly aided by the introduction of
roadside drug screening. This would be carried out if an officer
suspected impairment and if positive would give strong support
to the officer's suspicion.
A confirmatory test would still need to be taken
at a police station before any action against the driver could
be taken!
Evidence from a limited number of studies shows
that incidence of drugs in non accident involved drivers may be
quite high. Samples of saliva taken at random from over 1000 motorists
in Glasgow in 2004 showed around 10% were positive for an illicit
drug (IMMORTAL study www.immortal.or.au).
Until a much wider screening programme is carried
out, it is not possible to say whether this figure is typical
of GB as a whole, but almost certainly the number of drug drivers
being detected at the moment is just the "Tip of the Iceberg"
A study conducted by the Forensic Science Service (FSS) in 1995
of those drivers stopped and tested on suspicion of drug impairment
showed over 90% to be positive, many for more than one drug.
GB has the most serious illicit drug use problem
in the EU it would be surprising if this were not reflected in
drug driving figures.
The current law regarding drug driving is clearly
ineffective.
Section 4 of the Road Traffic Act 1988 (RTA)
requires it to be demonstrated that a driver is unfit to drive
if his ability to drive properly is for the time being impaired.
But, nowhere is the term unfit or impaired defined and thereby
lies the serious difficulty.
It has been known since the 1920's that alcohol
seriously affects a persons ability to drive, but it was not until
the Grand Rapids Study of 1962 that proved a clear correlation
between Blood Alcohol Concentration (BAC) and accident risk, not
impairment!, that legislation under the Road Traffic Act 1967
brought in a Per Se limit for drink driving. There is a clear
assumed relationship here between impairment and accident risk,
but this has never been clearly scientifically established, even
for alcohol. The situation with the myriad of drugs which may
cause impairment is an order of magnitude more complex.
What we do know is that in excess of 600,000
roadside breath tests are carried out each year in GB of which
around 100,000 are positive for alcohol above the legal limit.
Studies at TRL have shown that over 50% of these tests relate
to drivers under suspicion of impairment. There are therefore
in excess of 250,000 drivers stopped at the roadside per year
initially suspected of impaired driving who are below the legal
alcohol limit. Data from the Forensic Science Service (FSS) suggest
that less than 3000 of these are successfully pursued and prosecuted
for drug driving! The number of detected drug drivers is therefore
almost certainly "The Tip of the Iceberg"
Furthermore, analyses carried out by laboratories
authorised to carry out road traffic case drug analysis suggest
that the number of successful cases has not increased since the
Mandatory application of the Preliminary Impairment Tests (FIT)
in 2004.
3. CHANGING DRUG
DRIVING LAW
The North Report suggested a variety of possible
changes to drug driving Law.
One mentions the possibility of creating a new
"Zero Tolerance" offence of driving with an illicit
drug in the body.
I certainly welcome the exploration of such
an offence; I broached this issue in a paper to a PACTS conference
in November 2002.
The difficulties surround two issues: identifying
the drugs to which the law might apply and deciding on what concentrations
of drugs are evidence for a drugs presence. The later is relatively
straightforward, at least for evidential samples. There are acres
of toxicological data on this.
More difficult is the identification of drugs
of interest.
However, if we stick to the premise that our
only concern is with drugs which might impair driving; in my view
the task is not too difficult.
What we need to concentrate on is drugs which
have the ability to impair driving; then as with alcohol, impairment
relates to accident risk and therefore a road safety concern.
If the drugs don't cause accidents then we need not worry about
them!
Fortunately, All evidence suggests that 95%
of the problem is with drugs producing impairment relates to illicit
drugs, principally cannabis, opiates, amphetamines and cocaine.
However, also a significant problem relates to benzodiazepines,
which may be legally prescribed, but are widely abused.
There is very little evidence that other prescribed
drugs eg antidepressants or antihistamines administered to legitimate
patients at therapeutic levels present a road safety problem!
I would therefore suggest that any legislation
relates principally to these 5 groups of drugs. These cover 95%
of drugs likely to cause impairment; most of the rest would be
made up by LSD, GHB and Ketamine. All other illicits are hardly
ever used.
Secondly we need to consider Enforcement. The
following comments apply equally whether there are moves to bring
in a new Zero Tolerance or we retain the requirement to demonstrate
that the driver was impaired (possibly due to a drug).
My own view, as has ever been, is that we need
to bring in Roadside drug screening for drugs; As soon as practicably
possible!
A major point of issue in the original DfT consultation
of 2008/9 and the suggestion carried forward in the North report
is where best to carry an initial drug screening. The consultation
and North suggest screening at a police station!
But, All the advantages of screening come from
doing this at the roadside!
If the suspect drug driver needs to be taken
back to a police station for a test, large amounts of police time
will be wasted to no good purpose.
Furthermore, in order to do this the officer
will need to have more than a reasonable suspicion that the driver
is impaired. If this is the case, the officer could go straight
to an Evidential blood sample at the police station. What value
would an additional screening test add?
It is a little known fact that, although such
rarely happens, the police are allowed to require an evidential
sample currently, for alcohol, without offering a screening test!!
We therefore have the precedent in current drink
driving law.
The benefit of roadside screening for drugs
is that it is likely to detect more than 90-95% of drugs of concern
with greater than 90% accuracy.
Up until the very recent introduction of
digital roadside breath screening devices, roadside screening
for alcohol has been no more accurate than this and yet it has
driven forward successful enforcement of drink driving for more
than 40 years!!
Furthermore, A roadside screener would practically
allow the police to test the driver, even if there was only minimal
evidence of impairment, without risk of wasted time if the screening
test later proved negative (Probable minimum of half hour, more
likely at least an hour, plus the tie up of staff resources) of
returning to a police station.
Meanwhile resources would still be available
for roadside enforcement if necessary.
These are the major salient points as I see
them.
October 2010
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