Working conditions and fatigue among lorry drivers : Alcohol, drugs

W orking conditions and fatigue among lorry drivers :
Alcohol, drugs and driving safety : a literature study
M ic h e l V a lle t, S a la h K h a r d i
IN R E T S -L E N - case 2 4 - 69675 B ron C edex F ran ce
IN T R O D U C T IO N
T h e v ery specific w o rk in g and living co n d itio n s o f truck d riv ers affect their d riv in g and road
safety in gen eral. S u rv ey s an d resu lts p u b lish ed in th e literatu re are n ot alw ay s very convincing
and are o ften discrete about the im pact o f alcohol and d ru g s on accidents. N ev erth eless this
b o d y o f literature m erits detailed exam ination as it can help to identify and ascribe v alu es to the
p art p la y e d b y th ese d ifferen t facto rs in accid en t risks.
S o m e statistics u n d erlin e the high im plication o f tru ck s in accidents. 3% o f all the autom obiles
in the U S A are tru ck s (D ot 1995) and these account fo r 7% o f all the m iles d riven and 11% o f
all fatal accid en ts. T h is involvem ent rate w as o b se rv ed fo r the p erio d 1989-93 (D O T -N H T S A
1994) and it w a s a lso n oted that fatigue is a m uch h ig h er factor in accidents in v olving trucks
th an in accid en ts in v o lv in g cars alone. T h e ratio is 1 to 7.
W alsleb en (1 9 9 4 ), in a g eneral su rv ey on the im pact o f sleep in ess at the w heel o n p ro fessio n al
d riv ers, also n o tes th e h ig h in crease in accid en t risk s.
In F ra n ce, P. B o tto u sed the N ational A ccident O b servatory (SIA co n g re ss 1995) to exam ine
600 accid en ts in v o lv in g trucks and coaches, an d found the fo llo w in g statistics - tru ck s vs. cars:
4 8 % , tru ck s vs. tru ck s o r tru ck s alo n e : 35% , tru ck s vs. o th e r v eh icles : 17%
9% o f all accid en ts in v o lv e trucks.
L ack o f co ncentration is a freq u en t cau se w h en a truck ru n s into the b ack o f a tra c k it is
fo llo w in g . T h is ty p e o f accident accounts fo r 53% o f tra c k to track collisio n s - and o n ly 7%
w h en the v eh icle in fro n t is a car. T h is m ean s that the basic reaso n is n o t o n ly lack o f
co n cen tratio n . T he long q u eu es o f tru ck s w hich build up on m o to rw ay s is o n e o f the m ain
rea so n s fo r this ty p e o f accident. 57% o f coach accidents o ccu r at n ig h t and 7 0 % betw een 1
a.m . an d
8
a.m .. 50% o f all accid en ts o c c u r a t w eekends.
In a su rv ey carried o u t in the U n ited K in g d o m on a sam ple o f 9 0 0 0 p e o p le , M aycock (1995)
ex am in ed th e su b -g ro u p o f p ro fessio n al d riv ers. In th is B ritish T R L re p o rt, the su rv ey o n long
d istan ce d riv ers co n cern 9 9 6 track d riv e rs, aged betw een 2 0 and 6 0, d riv in g on average
1 1 5 ,0 0 0 k m p e r y ear, 2 /3 rd s o f w hich w ere on a m o to rw ay . 205 d riv e rs stated that they had
had 252 accid en ts o v e r a 3-year p eriod :
- 587 -
-
there is n o relatio n sh ip b etw een the frequency o f accidents and the total n u m b er o f kilom etres
-
accid en t freq u en cy is strongly linked to age : 0 .4 4 accidents in 3 years fo r the 17 to 29 year age
driven n o r th e n u m b er o f k ilom etres driven on m otorw ays,
group and 0.3 accid en ts fo r th e 55 and o v er age group (these figures w ere identical in the global
su rv ey fro m w h ich th e su b -g ro u p w as taken),
-
37% o f the d riv ers sn o red at night, w ere o ver-w eight (m easured at the neck) an d felt sleepy
d u rin g the daytim e. T h is g roup are tw ice as likely to have an accident than those w h o d o not
su ffer fro m sleep in ess (E pw orth scale). T he author believes that this o b serv atio n sh o u ld be
e x am in ed by fu rth er research.
W y c k o f f in th e U S A and the R egular C om m on C arrier C onference in its longitudinal study in
F lo rid a, (w o rk s rep o rted by H aw o rth 1991) found a lo w er accident risk rate than the T R C
su rv ey . O n av erag e, d riv ers have their first accident after 7 years driv in g ; b ut experienced
d riv ers have fe w e r accidents than novices. O u v erk erk , in the N etherlands (1988) reported that
in 1985-86, 16% o f 6 5 0 truck d rivers had had a traffic accident. L iving co n d itio n s have
chan g ed significantly since the first F ren ch study, p u b lish ed in the first n u m b er o f the rev iew ,
"Le T ravail H u m ain " (L ahy 1937) - quoted by H am elin 1994 - and even since the rev iew by
M acD o n ald in 1984. L ah y described the epic conditions o f truck d rivers as follow s:
"Au c o u rs de notre enquete n o u s nous som m es ren d u s com pte que ces h o m m es, q ui tous
aim ent leur m etier et ne voudraient pas en prendre un autre, epro u v en t u n e grande fatigue p o u r
accom plir leur travail. Us disent que cette im pression com m ence le so ir apres le depart de X
(so it ap res
12
h eu res d e v o y ag e environ)... et c'e st au p etit jo u r q u e les accidents se pro d u isen t
le p lu s s o u v e n t; ils e p ro u v en t d es troubles d 'ordre sensoriel, particu lie rem en t visuel ou tactile.
Ils n o u s o n t decrit d es cas d 'h allu cin atio n s h y p n ag o g iq u es. A in si, ils o nt la sensation d 'a v o ir
les y eu x o uverts et d e v o ir la ro u te dev an t eux, m ais leurs m ains ne sentent p lu s le vo lan t et ils
n 'en ten d e n t p lu s le ro n flem ent du m oteur. L 'u n d 'eu x racontait q u 'il lui arrive p arfo is de
s'arreter et de d escen d re au m ilieu de la route afin de s'a ssu re r q u 'e lle est assez large p o u r
p erm ettre au cam io n d e p asser. T he logical sequence accepted in the p ast u se d to be "the study
o f the w o rk in g co n d itio n s o f truck d riv ers, o f fatigue and then o f the risk s that they can
en g en d er" (H am elin 1994). T his has now ch an g ed d u e to the dem onstration o f several facto rs.
T h ese n ew d im en sio n s - alcohol, m edication and narcotics as w ell as natural o r pathological
m odifications to b io rh y th m s and vigilance are not a priori induced by w o rk in g conditions or
fatigue. I f the p ro b lem is analysed accurately w ith these notions in m ind, it can be adm itted that
som e o f th ese facto rs are m ore or less linked to w orking co n d itio n s an d that they can contribute
to the risk facto rs exam ined in d e t a il : the use stim ulants is an exam ple.
- 588 -
T R U C K D R IV E R S A N D A L C O H O L
In the m id 1980s, C h iro n reported that d o cto rs specialising in w o rkplace m edecine estim ated
that 10% o f truck d riv ers drank to ex cess (i.e. had becom e chronic alco h o lics), vs. 7 .4 % in a
the overall populatio n an d 10.4% in control-group w o rk ers : "It is am azing to fin d m ore
ex cessiv e d rin k ers d riv in g tru ck s than in o th e r jo b s!".
R eg u latio n s co n cern in g b lood alcohol content an d the effo rts o f co m p an ies, including
m o to rw ay o p erato rs, to red u ce and ev en p revent driving after the co n su m p tio n o f alcohol have
certainly been extrem ely effective. In fact, in a recent survey by IN R E T S (B iecheler 1994)
alco h o l w as d etected in 19.2% o f 71 4 d rivers: 15.1% w ith u n d er 0 .2 4 mg/1, 2 .4 % w ith 0.25 to
0.3 9 mg/1 and 1.7% w ith o v er 0 .4 mg/1 o f alcohol.
C urio u sly , o n e d riv er in fo u r ex cee d s speed lim its in the g roup w hich h as o n ly d ru n k sm all o r
m oderate am ount o f alcohol vs. 17% am ong so b e r d riv ers and those d riv ers w h o have d runk
m ore than th e lim it. T h e survey rev eal that am o n g truck d riv ers (3.9% o f the total sam ple) 6 .9 %
h ad a level o f b lo o d alcohol o f o v er 0.25 mg/1 and 0 .8 % d ro v e o v er the speed lim its w hereas
am ong o th er p ro fessio n al ro ad u se rs (5.4% o f the total), there w ere 0% w ith a b lo o d alcohol
rate o f o v er 0.2 5 mg/1 b u t 8.7% w ere breaking the speed lim its.
F ew resu lts h av e b een p u b lish ed about truck accidents and alcohol. S u m m ala (1994) fo u n d that
F in n ish tru ck d riv ers are very sober an d resist fatigue better than ca r drivers.
A lcohol usage d o es ap p ear in o th er studies detailing the pro p o rtio n o f d riv e rs involved in
accidents and th eir b lo o d alcohol rates. H aw o rth (1989) studied the p art played by fatigue in
truck accidents in A ustralia by analysing ju d g em en ts in law co u rts fo llo w in g in-depth rev iew s
o f each accident. T he factors exam ined reveal that accidents w ere caused by:
inattention
2 5 .3
clum sy driving
fatigue
9.1
on the w rong side o f the ro ad
15.1
speed
2 2 .0
difficulty w ith rem aining on the pav em en t
1 1 .8
alcohol
14
driving after taking m edication
3 .2
suicide
4 .8
o th er factors
2 6 .9
9.1
A s th e total ad d s up to m ore than 100, this m eans that several hum an facto rs contribute to the
accidents sim ultaneously.
In F ran ce, M o n tastru c (1 9 88) exam ined the resu lts o f biological blood assa y s (executed in the
hosp itals w h ere p eo p le inv olved in accidents w ere taken - an d therefore n ot o n ly truck drivers)
and fo u n d that 38% o f all peo p le in volved in accidents had been d rin k in g alcohol, an d had
som etim es taken n arco tics too. 22% o f the 57 0 casualties had been taking m edication o f som e
so rt.
-589-
N A R C O T IC S ,
M E D IC A T IO N
AND
S T IM U L A N T S
U SED
BY
TRUCK
D R IV E R S
T he potential d an g er fro m the effect o f m edication and narcotics on d riv in g vigilance
p reo ccu p ies public authorities and as G . L agier states (1955) th is subject is n o w included in
d riv in g tests.
F ren ch d riv ers use tran q uillisers to a great extent - 15% in the + 15 age g ro u p , 30% o f w h o m
are chronic u se rs v s. 6.7% in C anada w hich m akes F ran ce the 7 th big g est u se r o u t o f 45
n ations.
O n-going stu d ies com p aring d riv ers taking sedatives in volved in accidents w ith d riv ers w h o
have n o t had accidents show a rate o f 5 to 10% and even h ig h er. T he percentage is also
approxim ately 5 to 10% for narcotics usage in hospitalised d riv ers. T h is latter o b serv atio n is
co n firm ed by n o n -m an d atory tests w hich a m ajo r com pany reco m m en d s its d riv ers take d uring
norm al co n tro ls by w orkplace d o cto rs. L agier underlines the difficulty o f estab lish in g the
im p act o f n arco tics o n accidents.
T he analysis o f p o lice rep o rts on d riv ers arrested fo r "apparent dru n k in d riv in g " sh o w s a very
high p ercen tag e o f low o r zero alcohol rates. M edication a n d /o r narcotics are m ore resp o n sib le
fo r the states o f stupor.
L ag ier states that these effects are d u e to m any causes:
- se v era n ce effects,
- o v er-d o ses o f m ed icatio n,
-
non -sp ecific
effe cts,
particularly
at
the
start
of
- interaction w ith o th er m edication,
treatm ents,
- in teraction w ith alcohol.
- v ery rare but n o n -fo reseeab le effects,
In these 2 latter cases the com bined effects are m ultiplied.
T o this sho u ld be added pro b lem s w ith visio n created by som e m edications - particularly
an tid ep ressan ts.
T h ree categ o ries o f su b stances are co n sid ered to co u n ter sleepiness (R oussel 1 9 9 5 ):
-
caffeine m aintains aw aren ess and perform ance but its effect is fleeting and can lead to
u n d esirab le secondary effects du e to the rap id reduction in its efficacy w h ich en co u rag es u se rs
to take h ig h er and h ig h er doses. F rom 20 0 to 40 0 m g (2 to 4 cu p s), caffeine can cau se s tre s s,
agitation an d even ex cessiv e blood pressure,
am phetam ines have a rem arkable p o w er fo r k eeping people aw ake. T h is w as co n firm ed m any
tim es d u rin g the W orld W ar II. A m phetam ines are used by athletes as d o p e and are a true
n arcotic (tolerance increases as d o se s rise, leading to physical and p sy ch ic d ep en d en c e, w ith a
sev eran ce sy n d ro m e and high p ro d u ct need).
- 590-
S eco n d ary effects are dram atic on the card io -v ascu lar sy stem (high b lood p re ssu re and
tach y card ia), the gastro-intestinal sy stem (nausea, vom iting) and especially in the n eu ro ­
p sy ch iatric area (w ith p ro g ressio n tow ards d elirium ),
-
eu g reg o ric s, th e m o st efficacious o f w hich is M odafinil, are as p o w erfu l as am phetam ines for
m ain tain in g aw aren ess, d esp ite an extrem ely different biochem ical m ech an ism . T h e absence o f
m ajo r seco n d ary effects an d addiction m ake them the ideal m olecules fo r fig h tin g sleep
d iso rd ers b u t n o attem p t has b een m ade to m ake th eir use w idespread.
H o m e (1995) u sed a sim u lato r to study the stim u lan t ro le o f caffein e in coffee, tea o r chocolate.
It is efficacio u s o n fatig ued d riv ers but has very little effe ct on d riv ers w h o are fully aw ake. T he
resu lts ap p ear to be c o n v in cin g .
In th e F lo rid a stu d y (1 9 8 9 ), it is interesting to note that all the d riv ers q u estio n e d thought that
25% o f their co lleag u es regularly d ro v e u n d er the influence o f n arco tics. T o obtain objective
resu lts L u n d (1 988) carried o u t analyses w hich rev ealed , fo r 317 cases : cannabis : 15% , non
p rescrib ed s tim u la n ts : 12% , p rescrib ed stim u lan ts : 5% , co cain e : 2% an d a lc o h o l: 1%.
TRUCK
D R IV E R S
W ORK
D U R A T IO N ,
SLEEP
D E P R IV A T IO N
AND
F A T IG U E
In 1993, truck d riv ers in F ran ce w o rk ed fro m 49 h o u rs p e r w eek (w ith a daily return to their
co m p an ies) to 6 2 h o u rs p er w eek fo r fo u r-d ay trips (H am elin 1996). T he n u m b er o f h o u rs
w o rk ed p e r w e e k h a d n ot ch an g ed since 1983. T he tim e d uring w hich d riv e rs effectively drive
v a rie d fro m 28 to 4 2 ho urs.
H am elin (1990) estab lish ed a risk level d epending on the am plitude o f the w o rk , the pro p o rtio n
o f the jo b com p leted at night-tim e an d the d riv e r's com p an y categ o ry . T h e risk o f being
in v o lv ed in a corporal accident, at a given m om ent, is the q u o tien t o f th e nu m b er o f accidents at
that m o m en t an d th e n u m b er o f drivers ex p o sed at that in stan t. F ro m this calculation is appears
that the risk facto r fo r o w n er-d riv ers is m ultiplied by 3, particularly w hen d riv in g at night. It
w as also o b se rv ed th at th e risk facto r in crease s to 2.5 in the m id d le o f th e night an d to 1.7 w hen
d riv ers w o rk m o re th an
11
h o u rs p er day.
W o rk am plitude rein fo rces the chrono-biological asp ects o f accidents. W alselben (1994) in a
study o f th e S tate o f N ew Y ork, n oted that 44% o f all types o f accid en ts attributed to sleepiness
o ccu rred b etw een 1 and 7 a.m . vs. 10% in the overall sam ple. H o m e (1995) states th at in G reat
B ritain in accidents d u e to fatigue there is a daytim e p eak aro u n d 4 p .m . and tw o night-tim e
p e a k s a ro u n d
2
a.m . a n d
6
a.m .
M . C h iro n (1 9 8 6 ), w h en p rep arin g an epidem iological su rv ey on the p ath o lo g ies o f 25 0 38 t
truck d riv ers w o rk in g in larger than average co m p an ies asked a d o cto r to com plete 2 5 0
q u estio n n aires.
-591 -
Sleep in g tim e v aried w id ely from 3 hours 30 m inutes per night to 9 h ours 30 m inutes.
M ean d u ratio n w as
6
h o u rs 45 m inutes per night - w hich is relatively short.
8
% slept u n d er
6
h o u rs.
A seco n d su rv ey (L e P ro v o st et al.) on long-distance truck d riv ers sh o w ed that th o se w o rk in g
in shifts slept fro m 4 to 7 hours an d those driving alone fro m 5 to 7. A n extract fro m research
by G erm ain h ig h lights the significance o f daily variations in sleep duration as w ell as driving
d u ratio n (see p 9).
T h is short sleep d u ratio n facto r h as a high im pact on fatigue. B u t specialists c o n sid er that the
m o st im p o rtan t param eter is the total duration o f w o rk rath er than the tim e sp e n t d riv in g alone.
A lready su g g ested by L isper (1986), this distinction w as confirm ed by A kerstadt (1993) w ho
observed that the total tim e spent at w ork had a better correlation w ith sle ep in ess, asse sse d on a
self-sco rin g scale th an on driving duration.
R aggat (1 9 9 0 ) studied d riv ers o f long-distance coaches an d , m o re p articularly, stress facto rs.
T h e n u m b er o f hours spent at the w heel closely correlates w ith sleep d iso rd ers. T his stu d y also
identifies interrupted re st, catching up on schedules and en d o f a trip fatigue as sources o f
stress. V allet (1987) ex am in ed the low quality o f lon g -d istan ce truck d riv ers' sleep w ith gradual
degradation and m odifications to R E M sleep d uring the w eek , co n sid ered to be an invariable
p aram eter. R eco v ery o v e r th e w eekend is, in m o st cases, insufficient.
H o w ev er not all p ro b lem s o f sleepiness, the biological basis o f lack o f co n cen tratio n , are related
to lack o f sleep. T h ere are natural and pathological sleepiness co n d itio n s and in these ca se s,
alcohol, narco tics an d /o r m edication low ers aw areness and increases the risk s o f accidents.
In sleep d iso rd ers an d h y p erso m n ia, it is essential to differentiate betw een ex cessiv e sleepiness
d urin g the day tim e as d escribed by B illiard (1984) and the sudden sleep o f b u s d riv ers studied
by A rb u s (1 9 8 4 ). A su rv ey o f 27,141 y o u n g soldiers d re w attention to in voluntary sleep
p erio d s : 15.1% fell asleep occasio n ally , 3.1% on e o r tw o tim es a d ay and 1% m ore than tw ice
a day. It sho u ld be rem em bered that young adults fall asleep very q u ick ly . A sm all n u m b er o f
cases o f p aro x y stic h y p erso m n ia have been studied; this is a pathological condition rather than
fatig u e and is so m ew h at d ifficu lt to identify. H o w ev er the co n seq u en ces co n stitu te a ro a d safety
risk facto r.
E xp erim en ts in to m assiv e sleep deprivation dem onstrate m odifications
to psychological
b eh av io u r and n eu ro sen so rial capacities. It is easy to im agine the im pact on d riv in g . People
dep riv ed o f sleep fin d it v ery difficult to concentrate fo r sustained p erio d s and becom e m ore and
m o re ag g ressiv e, irritab le and less sociable.
M o n tp laisir (1995) sh o w ed that h y persom niacs m ake significantly m o re d riv in g erro rs in a 30
m inute test on the sim ulator (running o ff the ro a d , cro ssin g the c o n tin u o u s central o r roadside
lines and failing to resp ect ro ad signs) than the control g roup. F o r M ontplaisir only
h y p erso m n iacs ru n o f f the ro ad and this seem s to be related to m icro -sleep . T h e sim ulated
driv in g test seem s sufficiently sensitive to detect drivers w h o co u ld fall asleep w hen driving.
-592-
O v er the last 10 years o r so, p articu lar attention has b een d ev o ted to sleep ap n o ea an d its im pact
on d ay tim e sleep in ess w h ich can becom e hypersom nia. L eg er (1995) g iv es a g o o d sum m ary o f
the g en eral p ro b lem , th e state o f o u r know ledge and risk s o f accidents.
Sleep apnoea sy n d ro m e is characterised by the appearance o f resp irato ry arrests d uring sleep.
T h ese last u n d er 10 seconds b ut can o ccu r 5 o r m ore tim es p e r hour.
A ccording to the literature,
1 to 8.5%
In m en th e p ro b lem in crease s w ith age :
o f the populatio n
su ffer
fro m
th is d iso rd e r.
to 15% after 40, 25% o v e r 65 an d is o ften associated
8
w ith card io v asc u la r d isorders.
D aytim e sleep in ess, and its im pact on car d riv in g , ap pears in 60% o f people suffering from
sleep ap n o ea vs. 3 to 12% in general.
P eo p le su fferin g fro m sleep apnoea have fiv e tim es m ore accidents an d accidents d u e to
sleep in ess are m o re n u m ero u s, 13% v s. 3% in the control g roup. "N ear m isses" are 9 tim es
m ore freq u en t. In addition to this bibliographic app ro ach , L e g e r's resea rch co m pared 90
w o rk ers su fferin g fro m sleep apnoea w ith 50 w o rk ers in a control g ro u p including m ore
w o m en . T he in-depth questionnaire used dem onstrates resu lts fo r sleepiness in trucking for
accidents at w o rk an d o n the ro ad :
-
in tru ck in g , sleep in ess co n cern s :
-
58.4 %
62%
of
sleep
o f sleep
ap n o ea
ap n o ea
su fferers
sufferers
in
in
the
the
m o rn in g
evening
v s.
v s.
4%
of
the
co n tro l
26 .5 %
of
the
control
group
g ro u p ,
the w o rk accident rate is identical in both gro u p s but sleep apnoea su ffere rs have m ore "near
m isses" (1 4 .9 % vs. 0 % ),
-
sleep apnoea su fferers h ave m ore ro ad accidents, but the difference is n o t significant
(7 .3 % v s. 2% ).
3 4.5 % o f sleep ap n o ea su fferers vs. 4% in the control g roup say they have alm ost had an
accid en t and am o n g those w ith apnoea, sleepiness is the m o st frequent reaso n given.
Sm iley (1 9 9 5 ) states that C anadian d riv ers w ith sleep apnoea p ro b lem s p erfo rm less w ell in
trajectory-follow ing tests an d visual exploration than healthy subjects an d those w ith 0 .0 8 g/h
alcohol in th eir blo o d . F o rtu n ately , sleep ap n o ea can be treated successfully.
In a specific study o f fatigue-related truck accidents, M ay co ck (1 9 9 5 ), d isc u sse d the possibility
o f sleep ap n o ea and supposed, narcolepsy sym ptom s in d riv ers d u e to ex trem e resu lts scored on
the E p w o rth sleep scale.
A ustralia h as ru n several sleep apnoea research p ro g ram m es. B e arp ark (1 9 8 9 ), com pared
accident rates in three different g ro u p s o f car d riv ers : sleep ap n o ea su ffere rs, sn o rers and a
control g ro u p . Sleep apnoea su ffere rs stating they had had accidents cau sed by sleep in ess is
sig n ifican tly h ig h er (19% ) than snorers (3% ) an d the co n tro l group ( 8 % ). 57% o f "sleep ap n o ea
sufferers" rep o rted th at d u e to sleepiness they had run o ff the ro ad several tim es o r frequently
(w ith o u t
an
accident)
v s.
the
"snorers"
(32% )
an d
the
control
g ro u p
(3 3 % ).
Sleep ap n o ea sufferers an d snorers fell asleep m ore often at traffic lights than the co n tro l group.
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B ased o n th e o b serv atio n s m ade by B olz (1988) and G illespie (1988) o f the alarm in g n u m b er o f
truck d riv ers su fferin g fro m sleep apnoea, B earpark recom m ended m o re detailed m edical
ex am in atio n s fo r truck d riv ers, because their lifestyle (obesity and the c o n su m p tio n o f alcohol
and the task s their jo b in v o lv es, particularly long distance d riv in g , im plies g reater risk s o f
falling asleep at the w h eel. S tradling (1989) concluded that "all sleep ap n o ea su ffere rs holding
d riv in g licences fo r public o r g o ods vehicles sh o u ld be invited to stop d riv in g until they have
com p leted a successful m edical treatm ent".
P ak o la and D inges (1 9 9 5 ), during a rev iew o f regulations co n cern in g sleep d iso rd e rs and
d riv in g , o b serv e th at the general rule is to p rev en t d riv ers fro m d riv in g fo r 3 to 12 m o n th s so
that they can seek effective therapy even if it has not been fully elu cid ated w h eth er accid en t risks
are h ig h er o r not.
C O N C L U S IO N S
T ru ck d riv ers d rin k m o d erate am ounts o f alcohol and it seem s p ro b ab le that actual p ro g re ss in
this pattern is extrem ely recent. N arco tics, m edication and stim ulants are alm o st m ore
w id esp read than alco h o l. T he im portance o f w o rk in g co n d itio n s and sleep d iso rd e rs h as also
been em p h asised . C o n fro nted w ith these m any facto rs co n trib u tin g to d riv er lack o f v ig ilan ce, it
seem s sen sib le to su g g est th at an effort be m ade to globally im p ro v e d riv ers irreg u lar h o u rs and
w o rk d ay len g th . O ther approaches w o u ld co n sist in p ro v id in g full in form ation and even
o rg an isin g co n tin u o u s training program m es about the facts th at alcohol an d m edication increase
n atu ral risk s and th o se in d u ced by sleep disorders.
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