Does the liberalization of alcohol policy effect on incidency of drunk driving and on psychosocial mechanisms behind drinking and driving M artti M aki T he C entral O rganization for traffic safety in Finland T h e b est w ay to intro d u ce you to the F innish alcohol culture is to hav e a sh o rt lo o k at the Finnish tradition o f alco h o l policy. A s early as in 1865 cam e into fo rce the law w hich crim inalized th e b urning o f hard spirits at hom e.t he m ain p u rp o se o f the new legislation w as to re stric t the consum ption o f alcohol in o rd er to p rev en t th e harm s o f alcohol u se.t h e 1865 law w as the starting p o in t o f the strict Finnish alcohol policy. T he effect o f official norm s w as rein fo rced by the inofficial su p p o rt o f the active tem p eran ce m ovem ent. T h e strong w ill to avoid high alcohol consu m p tio n and the harm s and social co sts o f it w as sharp en ed to the in tro d u c tio n o f the Prohibitory law in 1919, tw o years after T he Independence. T h e stric t leg islation led to m any kinds o f illegal activities, f.inst. sm uggling spirits. D u e to unfunctions the P rohibitory law w as can celled in 1932 and the new A ct o f H a rd Spirits w as introduced. A cco rd in g to the law the state had the m onopoly o f the w hole alcohol business, supervision, an d rig h t to d eterm ine the prices o f alcohol. T h e strict alcohol policy h ad an effe ct on drinking habits an d attitu d es to w ard s alcohol. T he Finnish co nsum ption o f alcohol befo re the year 1968 w as internationally very low, about 2-4 litres o f absolute alcohol per capita yearly. T h e first step to w ard s a m o re o p en -m in d ed alcohol policy w as taken in 1968 w h en the act o f m edium strength b e e r (alcohol stregth below 3.7 %) cam e in to force. A ccording the law th e selling o f m edium b eer w as allo w ed on food m ark ets and groseries. D ue to the law the consum ption of alcohol increased ab o u t 4 0 % an d e.g. the police re p o rte d that d runk driving rose 20 p ercen t from 6889 (1968) to 8360 (1969). Finally the A lcohol A ct w hich cam e in to fo rce in the beginning o f 1995 liberalized largely the Finnish alcohol policy. T he state alcohol m o n o p o ly w as broken, m ild alcohol b everages co u ld be b ought on m arkets and groceries, supervision o f alcohol use has been d ecreased and the advertising o f alcohol b everages ( alcohol contents less than 22 %) is allow ed. The total am o u n t o f alcohol consum ption increased fro m 8.0 0 litres o f absolute alcohol p er capita in 1994 to 8.70 litres in 1995 and 8.91 litres in 1996. T h e p u rp o se o f the study is to describ e the d ev elopm ent o f drunk d riving after the alcohol act and to m o n ito re the ch an g es o f psychosocial m echanism s behind drunk driving. - 893 -
Incidence of drunk driving during the alcohol act D u e to previous research, w e k n o w th at th e increase o f alcohol consum ption w ill cau se m o re social problem s, an d m o re d ru n k driving, too. T h e alcohol act o f the y ear 1995 in creased the use o f alcohol ab o u t 11 % (O sterb erg 1996). It can be pred icted that, in addition to oth er social harm s like violence, the effect o f the liberalization o f alcohol policy in 1995 and 1996 w ill also increase the frquency o f drunk driving, com pared w ith earlier years. T able 1 includes the data o f alcohol use (litres o f absolute alcohol p er capita), d ru n k driving rep o rted by police, d ru n k driving by ro ad sid e surveys and drunk driving by interview studies. T ab le 1. show s th at w e can find only slight changes o f any indicators o f d runk d riving d u rin g years 1993-96. If w e look at police re p o rte d d ata (C olum n B) w e w ill see som e linear increase from 1994 to. 1996. A s to roadside survey results (C olum n C) d ru n k driving seem s to have an increasing trend. W e have the sam e p ictu re w hen w e look at self rep o rted drunk driving. In conclusion, there can be seen only m inor effects on drunk driving caused by liberalization of alcohol policy by up till 1996. Table 1 C onsum ption of Alcohol, Incidence of D runk Driving in Term s of Police reported Data, self reported Data and Data of Road Side surveys in Years 1985, 1993-1996 Year Incidence of Drunk Driving Consum ption of Police repor Self repor Road Side Alcohol, total 1) ted 2) ted 3) Survey 4) 1985 6,46 21262 19 0,20 (0.04) 1993 8,18 22104 22 0,22 (0.02) 1994 8,00 20390 21 0,22 (0.04) 1995 8,70 21098 23 0,24 (0.04) 1996 8,91 21412 22 0,25 (0.05) 1) = Litres of Abs. alcohol per C apita 2) = Absolute Numbers of Drunk Drivers 3) = Yes-Answers-% to the Question: "Have you ever driven although you have known that your BAC is ovover legal limi (Surveys 1985, 1995, 1996) 4)= Percentage of Drunk Drivers in Traffii, It m ay be th at the follow -up p erio d has been to o sh o rt fo r the appearence o f changes caused by the new alcohol law. P sychosocial m echanism s behind drunk d riving D o drivers experience safety values, o beying th e drinking and driving law, relationships to prim ary groups, social p ressu re and use o f ow n c a r so im portant that they will prevent drunk driving? T hese issues are analysed in this chapter. - 894-
Methodological aspects R esults w hich are in tro d u ced in this c h ap ter are b ased on a follow up survey, th e p u rp o se o f w hich is to m onito re possible ch anges o f d ru n k d riving cau sed by th e new alcohol act. D ata have been co llected by in terview ing the o w n ers o f d riv er licence. T he random sam ple has been d raw n o f d riv er lisense register. D a ta consist o f interview s o f the years 1985, 1995 an d 1996. T h e y e a r 1985 is u se d as a reference year o f the changes. T ab le 2. d escribes th e data. Table 2 Pergentaces of Gender and Age Distributions of Survey Data in 1985,1995-1997, and Data of Finnish Licence Owners of 1997 G ender Survey Data Finnish Licence Owners 1985 1995 1996 1997 1997 N % N % N % N % N % Male 133 54 181 53 195 55 196 56 1 703 506 57 Fem ale 113 46 169 47 157 45 157 44 1 293 457 43 Total 246 100 360 100 352 100 353 100 2 996 963 100 18-24 33 13 55 15 43 43 12 12 4 1 6 9 1 6 14 25-34 97 39 88 24 76 79 22 22 592 164 20 35-49 70 28 109 30 130 127 36 37 1 068 488 36 50-46 20 108 31 103 103 29 29 919 395 30 Total 246 100 360 100 352 353 100 100 2 996 963 100 D ue to the m ethod o f sam pling, m en and drivers y an g er than 35 are o v erprented in the m aterial. A m ong driving licence ow ners, th ere are m o re m en an d young p eople than in the average population. B efore the analysis th e data has been classified to d runk d riv e r g roup and sober d riv e rs group by the an sw er w ether the d riv er has driven d runk o r not. Safety V alues H ealth is highly v alued by Finnish p eople. T raffic safety p ro m o te s health values. T h a t's why drivers su p p o rt traffic safety goals on the average. D rivers w an t to av o id accidents, traffic death an d injuries. T he m o re im p o rtan t traffic safety is fo r th e driver th e stro n g er is her/his w illingness to m an ag e in traffic w ith o u t any accidents. B u t there are som e facto rs w hich disturb achieving traffic safety goals, o f w hich one o f the m o st im p o rtan t is alcohol use in traffic. A lcohol has an effects e.g. on self control w hich m eans th at conform ity w ith traffic norm s, also w ith drinking and driving law s, will decline and th e thresh o ld o f d ru n k driving will becom e low er. T he m ore a d riv er has been drinking th e m o re p ro b ab le her/his value system and her/his ability to ju d g e correctly her/his d riving skills w ill be disturbed. In these cases accident proneness will highly increase. - 895 -
T able 3 show s the changes in the im p o rtan ce o f traffic safety ex p erien ced by drivers. T raffic safety is o p eratio n alized by th ree variables: I m ight have been involved in traffic accident, I m ight hav e injured o th ers in traffic an d I m ight have been injured m yself in traffic. Table 3 Percentages of Safety Variables by Drinking and Driving Drunk drivers Sober drivers 1985 1995 1996 1997 1985 1995 1996 1997 N=24 N=45 N=48 N=52 N =165 N =167 N =170 N=179 1could have been involved in fatal accident Im portant 42 85 79 77 92 78 86 84 Not important 58 16 21 23 8 22 14 16 I m yself could have been injured if I would have been driving Im portant Not important N=24 N=45 N=46 N=52 N=165 N=167 N=167 N=1 75 42 64 85 77 88 78 85 82 58 36 15 23 12 22 15 18 I could have injured other roadusers if I w ould have been drinking Im portant Not important N=24 N=45 N=46 N=52 N = 1 65 N = 1 67 N =167 N=177 42 87 63 85 93 79 84 86 58 13 37 15 7 21 16 14 S o b er drivers have a strong ten d en cy to avoid accid en ts (9 6 % -8 6 % o f answ ers). T he im portance o f accident involvem ent has d eclined 14 % -units from 1985 to 1995 but still rem ained on the high level (86% ). T he resu lt m ean s th at sober drivers set high values to successful, safe driving. D runk drivers seem ed in 1985 to think th at to be involved in traffic accident is n ot a big issue. In their opinion alcohol w ill not d ete rio ta te d riving skills so m uch that it w ould prevent people from driving. D uring ten years th e ir w ay o f thinking has changed. It has approached linearly the attitudes o f sober drivers. In 1996 four o f five drunk drivers found avoiding traffic accid en ts as an im portant issue. T he fear o f getting hurt has grow n clearly in this g roup(by 43% ). T oday they also w an t to p ro te c t them selves ag ain st accidents. Injuring others in traffic w as n o t very m eaningful for d ru n k driv ers in 1985, because a great m ajority did not perceiv e the im portance o f n o t injuring others in traffic. B ut in ten years responsibility for o th er ro ad users has increased so m uch that drunk driv ers rate the safety o f o th e r drivers as high as so b e r drivers. In 1995 and 1996 the im portance o f o th e r ro ad u se rs ' safety has d ecreased clearly while the consum ption o f alcohol has increased, w hich su p p o rts the assum ption that alcohol co n su m p tio n an d involvem ent in safety v alues are correlating negatively w ith each other. - 8 9 6 -
T raffic safety is highly valued today as can be seen from the results. T he incidence o f d ru n k driving has slightly increased b u t traffic d eath s in accidents w h ere d ru n k d riving has been involved have increased fro m 54 (1985) to 83 (1995). T h ere is d ru n k drivers w h o value safety highly but, n evertheless, becom e involved in fatal accidents. T hey have n o t h ad abilities to follow safety values w hich in the reason w hy they have becom e in v o lv ed in accidents T h e im p o rta n ce o f con form ity a n d referen ce groups T o su p p o rt safety goals society has a ccepte d regulatio n s w hich have denied drinking an d driving because it includes to o m uch risky elem ents. A great m ajority o f drivers d o obey the law, only ab o u t 0.25 % o f active d rivers deviates from the law acco rd in g to road side surveys. T he inw ard sense o f follow ing the law m akes drivers avoid driving w hile in toxicated. O n this bases it is assum ed th at drivers w ill value the law and the m eaning o f en fo rcem en t and being sentenced fo r drunk driving. Table 4 P ercentages of Estim ations of Razzia Involvem ent and D runk Driving S entence by Drinking and Driving 1could have been involved in razzia/ got sentenced on drunk driving Drunk drivers Sober drivers 1985 1995 1996 1997 1985 1995 1996 1997 N=25 N=45 N -50 N -52 N=167 19=167 N=172 N -183 Im portant 68 73 85 83 88 75 83 83 Not important 32 27 15 17 12 25 17 17 S o b er drivers avoided circum stances w here they w ould have been se n ten ced for drunk driving very strongly (88% ) in 1985. A lso, d u rin g the w hole m onitoring p erio d a m ajority o f d ru n k d rivers has been fully aw are o f the im portance o f abeying the law. In 1985-96 the su p p o rtin g figures have risen linearly (68% -85% ) achieving the level o f so b e r d riv ers. The subjective risk has been reg ard ed g re a te r than earlier. T he legislation seem s to function as a preventive m easure in a p ro p e r w ay in spite o f the increase o f alcohol consum ption. R eferen ce groups A d riv er belongs to m any kinds o f social groups. T he stro n g e r the cohesio n o f the g ro u p th e m o re the driver will follow the norm s o f the g ro u p and av o id the d ev ian t behaviour. T h e m o st im p o rtan t g roups are norm ally fam ily and friends. A lso w o rk in g environm ent w ith its g ro u p s is valuable. - 897 -
T o keep group and hum an relations functioning, a d riv er w ill avoid disturbances w hich w ould dam age the balance and harm ony o f hum an relatio n s. B u t again, alcohol use m ay spoil the w hole picture. If the d riv er experien ces fam ily and friends im portant enough, and they d o n t acce p t d ru n k d riving th e cohesion to these groups w ill p ro te c t the driver from d ru n k driving. B u t if th ere are not enough intensive feelings no p rotection exists, an d being a g ro u p m em ber does not function as a preventive m easure against drunk driving. U sually p eople also feel that w orking environm ent is im p o rtan t an d negative reactions at w orking places m ust be avoided. B u t those w h o use alcohol a lot have started to think th at getting alcohol is m o re im p o rtan t than co lleag u es' reactions o r even loosing the job. Table 5 Percentages of Appreciation of Reference Groups by Drinking and Driving Drunk drivers 1985 1995 1996 1997 Sober drivers 1985 1995 1996 1997 It would be unpleasant for my family if 1would have been N=24 N=45 N=47 N=52 N =167 N=167 N=167 N=1 77 sentenced on drunk driving Important 77 82 81 85 87 74 81 77 Not important 23 18 19 15 13 26 19 23 My friends would react negatively to my drunk driving N=24 N=45 N=47 N=52 N=1 63 N=169 N=167 N=177 Important 71 64 57 65 83 67 80 70 Not important 29 36 43 35 17 33 20 30 My drunk driving would cause problems in my job N=24 N=45 N=47 N=52 N =161 N=169 N=163 N=1 77 Important 67 57 57 65 56 65 64 59 Not important 33 43 43 35 44 35 36 41 F o u r o f five drivers appreciates fam ily relations. T hey d o n t w an t to d am age the fam ily life by th eir im proper behaviour. N o great differen ces can be seen in this m atter betw een the groups. S ober drivers will also set m uch w eight on relationship w ith friends, in fact as m uch as w ith the fam ily. B ut d runk drivers d o n t appreciate friends so m uch. T hey will do w hat they d o w ithout taking in to acco u n t th eir frie n d s negative reactions. T his tendency has been intensifying from 1985 (71% ) to 1996 (57 %) It can be n o ted that in this group the preventive p o w e r seem s to be restricted only to the fam ily. B ut in any case the m ajority o f d ru n k d riv ers, to o, will apprecite friendships. A w areness o f the im portance o f pro b lem s in jo b which will be caused by d runk driving in jo b has increased from ab o u t fifty six p e r cent to tw o thirds o f the answ ers in the group o f so b e r drivers. T h ey value their career and avoid all risks to loose their job. - 898 -
AU drivers experience the role o f the fam ily quite im portant. S o b er drivers appreciate also friends an d reactions in w orking place.a m ajo rity o f drunk d rivers is also aw are o f the im portance o f conform ity w ith the law, but there is a strong tendency to ignore friends and jo b related pressures. T h e in flu en ce o f o u tsid ers on th e d ecision m aking o f the d riv ers M o st d runk drivers have assessed that they have been able to driv e safely while d riving u nder the influence o f alcohol. Feeling like this, they have not seen any d ange in driving their car. If the d riv er thinks that he can driv e safely after drin k in g alcohol, one could assum e th at it is extrem ely d ifficu lt to p rev en t the d riv er from driving. H e h im self m ake the decision o f driving. S econdly, if others think that he sh ould drive or if they urge him to drive then the driver becom es reinforced in his decision m aking. T his is the case, the m ore drunken driver is, and the others are. Table 6 Percentages of the Effect of C om panions on Driving Decision by Drinkin and Driving Drunk drivers Sober drivers 1985 1995 1996 1997 1985 1995 1996 1997 Com panions wanted that 1would drive N=24 N=45 N=46 N=52 N =112 N=163 N=161 N=175 Important 25 22 28 15 10 16 20 11 Not important 75 78 72 85 90 84 80 89 Companions didn't want that 1would drive N=24 N=45 N=46 N=52 N=156 N=163 N=163 N=175 Important 29 29 41 29 37 34 36 30 Not important 71 71 59 71 63 66 64 70 Only, one o f ten sober drivers in 1985 thought that it is im p o rtan t fo r decision m aking if others w ant him to drive after drinking. E leven years later th e percent has doupled. A q uarter o f drunk driv ers has got su p p o rt from outsiders in m ak in g the decisions o f driving after drinking in 1985. It is tw o and a h a lf tim es m o re than in the group o f sober drivers. In 1995 and 1996 the percen tag es have rem ain ed about the sam e. R esults show that - in spite o f the m inority o f p ro n en en t drivers - the social pressure is a m eaningful facto r in m aking driving d ecisio n s after drinking. A n d it can be assu m ed that the increasing alcohol co n su m p tio n correlates with social pressure. A lso in the opposite case, if others d o n 't w ant the driver to d riv e after d rinking it has influence in about tw o cases out o f five. The im portance o f this influence has increased in ten years in the group o f drunk drivers (12 % -u n its). It m ay - 8 9 9 -
be that drivers are m ore w illing to adm it the influence o f negative attitudes tow ards o th er drivers drunk driving w hen they hav e been in terview ed. In any case, the influence o u tsid ers opinions on d riving after drin k in g cannot be underestim ated. It can also have preventive pow er. D ep en d en ce on th e use o f ow n car If the driver w ill avoid drunk driving after drinking he sh ould use public transportation and plan the use o f ow n c a r so that it is p o ssib le only w hen he is able to drive safely. In cases w hen driver is quite d e p en d an t on the use o f his ow n c a r he is probably unw illing to use a bus, to p o sp o n e the d riv in g to next day or, as a ru le, to plan oth er form s o f transp o rtatio n than using his ow n car. A d ependant d riv er thinks that ow n c a r is the easiest, m o ste conom ical and m ost practical m eans o f transportation after drinking, too. Table 7 Percentages of Estim ations of Practical C auses by Drinking and Driving Drunk Drivers * Sober Drivers 1985 1995 1996 1997 1985 1995 1996 My personal driving was the easiest or the only way to reach the goal N=24 N=45 N=47 N=52 N=152 N=158 N=163 Im portant 83 41 47 44 24 28 37 Not important 17 59 53 56 76 72 63 100 100 100 100 100 100 100 My personal driving was the cheapest way to reach the goal N=24 N=45 N=47 N=52 N=152 N=163 N=163 Im portant 38 11 36 29 15 22 30 Not important 62 89 64 71 85 78 70 100 100 100 100 100 100 100 I had to take m y car because I needed it later on N=24 N=45 N=46 N=52 N -152 N -161 N=161 Im portant 67 35 52 37 23 22 32 Not important 33 65 48 63 77 78 68 100 100 100 100 100 100 100 *= Classified on the Base of the Answers to "Have you ever som etim es driven althhough you have known that your BAC is over the legal limit (0,5 o/oo)" T ab le 7 show s th at one o f fo u r so b e r d rivers in 1985 th o u g h t th at usin g ow n car is the easiest w ay or the only m eans to reach the goal. T he im p o rtan ce o f this -9 0 0 -
opinion has in creased linearly 13 % units by 1996. T he m ost rem ark able change has h appen ed b etw een 1995 and 1996, during the new alcohol act. B ut still these w ho re g a rd the use o f ow n car im p o rtan t after d rin k in g are the m inority. In the group o f d ru n k driv ers fo u r o f five in 1985 th o u g h t th at the use o f ow n car has been the easiest w ay o r the only m eans to reach the goal after drinking. In ten years th e fig u re has com e dow n fifty percent, w hich c o u ld m ean that attitudes to w ard d riv in g after drinking have becom e stricter. F rom 1995 to 1996 the attitude has been lo o senin g again a little. It seem s, how ev er, th at it is m ore characteristic fo r d ru n k drivers than fo r so b e r drivers to ex p erien ce the o f the use o f ow n c a r im p o rtan t. N early for a h alf o f drunk drivers it is d ifficu lt to give up the use o f ow n car. W hat com es to the costs o f usin g o n e s ow n car, only 15 % o f sober drivers thought in 1985 that the low costs are a m eaningful m otive to use o n e s ow n car after drinking. B ut by 1996 the im portance o f the low costs o f using o n e s own car has increased by 50 %, linearly. D runk drivers appreciate m o re than sober drivers the im p o rtan c e o f low costs, as they assess the co sts o f car use. In years 1995-96 the ap p reciatio n o f low costs o f car use has in creased 25 % units in the group o f d ru n k drivers. It could be w ell said that if the d riv er feels a need to drive after drin k in g he certainly does not very m uch have in m in d the costs of driving a private car. T he reaction to the need o f ow n c a r is quite different in the g roups o f sober and drunk drivers. In 1985 tw o thirds o f drunk drivers, ag ain st one fifths o f sober drivers, thin k th at th e later need o f ow n car is im p o rtan t, in fact so im portant that it overco m es d ru n k driving. T his tendency has in creased in the group o f sober drivers ab o u t 10 % units by 1996(32% ) and d ecreased in the group o f drunk drivers ab o u t 15 % units (52% ). Still a little m ore than h a lf o f drunk drivers thin k th at the later use o f ow n c a r is im p o rtan t en o u g h to allow to drive after drinking. S o b er drivers are m ore able than d ru n k driv ers to plan the use of ow n car in cases re la te d to drinking, they are m ore indepen d en t in their driving In conclusion, sober driv ers are m ore independent in th eir c a r use than drunk drivers. P ra ctical issues like the easiness o f using o n e s ow n car, lo w costs o f driving and the n eed o f ow n car are im portant fo r d ru n k driv ers an d determ ine the pattern o f d riv in g after drinkin m ore than in the group o f so b e r drivetrs. But the im portance o f a.b. variables have increased in both groups in 1995-96. D iscussion The new alchohol act cam e into force in F inland in the b eginning o f 1995. The act liberalised the F in n ish alcohol policy w hich increased the consum ption of alcohol. E arlier reseach has show n that alcohol consum ption co rrelates p o sitively with dam ages cau sed by alcohol. B ased on this know led g e it is assu m ed that during the A ct (in 1995-96) the am ount o f drunk driving in F in lan d sh o u ld be increased. O n the o th e r hand, it is assum ed that values w hich p rev en t drunk -901 -
driving such as safety values, conform ity w ith drinking and driving laws, appreciation o f fam ily, friends and w orking enviro n m en t and in addition variables like social pressure and dependence on c a r use w ill be influenced by the increase o f alcohol use o f drivers. A ccording to the hypothesis drunk driving has increased slig h d y during 1995 and 1996 if w e look at the police reported data, self reported data and the results o f road side surveys. O bviously the new act has not increased d runk d riv in g so effectively as su p p o sed T he resu lt im plies that the values w hich p rev en t d runk driving have not been altered greatly. Safety seem s to be im p o rtan t fo r all drivers but drunk d riv ers' b elief o f not dam aging other road users w h en d riv in g drunk has increased in 1995-96. Fam ily is highly valued by all drivers, b u t drunk drivers d o n 't appreciate the reactions o f friends and w ork in g enviro n m en t as m uch as sober drivers do. P articularly the developm ent in 1995-96 concerning reactions in w orking en v iro n m en t has been opposite in the g roups o f d runk and sober drivers. T he im portance o f the reactions o f w ork in g enviro n m en t has increased in sober and decreased in drunk driver group. D runk drivers have proved to be m ore car d epen d an t th an so b e r drivers. The tendency has being strenthened during the A ct. A lm o st h alf o f drunk drivers felt in 1996 that ow n car is the m ost convenient w ay o f transportation also after d rinking and the later need o f ow n car allow s to driv e after drinking. O n the groups o f the results, it can be said that during the A ct safety an d fam ily values and conform ity w ith drinking and driving law are highly appreciated,and the im portance o f friends in the group of sober drivers has strengthened. T he m eaning o f friends and w orking environm ent as a decreased preventive pow er, social p ressure to drive after d rinking an d the c a r dependence in the group o f d ru n k driv ers during the A ct m akes one th in k that the A ct has two sided effects. In the group o f sober drivers the A ct can be connected to the strengthening process o f preventive pow ers an d in the group o f drunk drivers to the w eakening o f som e protecting social references like friends and w orking environm ent, and to the strengthening o f variables supporting drunk driving like car dependence and social pressure to drive under the influence o f alcohol. It m ust be rem em b ered that the data o f the in terview s include som e biases. W e d o n 't know how confident the answ eres are. In the study like this it is probable that drivers are w illing to give socially acceptable answ ers and answ ers they think are hoped for. In som e cases they d o n 't w an t to an sw er at all which increase the frequency o f no answ ers o r d o n 't k n o w. It w eakens the reliability o f the results. T he follow ing up period w as only tw o years w hich p erhaps d o e sn t give a true picture o f the behav io ral changes after the A ct. M ore tim e is needed to form m ore co ntrolled and com prihensive understanding o f the effects o f the Act. -9 0 2 -