Do drivers become less risk-prone after answering a questionnaire on risky driving behaviour?

Accident Analysis and Prevention 42 (2010) 235–244

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Do drivers become less risk-prone after answering a questionnaire on risky driving behaviour? Birgitta Falk ∗ Department of Psychology, Stockholm University, SE 10691 Stockholm, Sweden

a r t i c l e

i n f o

Article history: Received 18 December 2008 Received in revised form 13 May 2009 Accepted 1 August 2009 Keywords: Driver behaviour Persuasion Self-report Young drivers

a b s t r a c t Two studies showed that answering a questionnaire regarding self-reported risky driving behaviour and attitudes led to a significant (p < 0.001) decrease in self-reported risky driving behaviour at a follow-up some five weeks after answering the first questionnaire. In Study I participants (193 men, 18–20 years old) also reported more concern about hurting others, increased subjective probability of accidents, but less thinking about injuries at follow-up. In Study 2 (149 men, 18–19 years old) effects on attitudes at follow-up were not tested. The results are discussed in terms of the question-behaviour effect, that is, questioning a person about a certain behaviour can influence his future performance of that behaviour. Assuming that most young male drivers essentially disapprove of traffic violations, it is argued that answering the questionnaire served as an intervention that made attitudes more accessible and led to a polarization towards stronger disapproval of traffic violations, which in turn influenced reported risky driving behaviour. The need to develop alternative instruments for evaluating effects of experimental traffic safety interventions is also discussed. © 2009 Elsevier Ltd. All rights reserved.

1. Introduction Is it possible that the mere act of answering a questionnaire regarding personal risky driving behaviour can have effect on subsequent driving behaviour among young males? It is widely acknowledged that young drivers, and particularly young male drivers, are over-represented in traffic crashes and also perform risky behaviours like speeding and close following more often than other drivers do. It is also acknowledged that such risky behaviours are difficult to change (OECD, 1994), and that this especially applies to high-risk groups (Lewis et al., 2007; Ulleberg, 2001). The scope of the problem of high crash risks of young drivers, especially young men, was documented in a recent publication, Young drivers: the road to safety, by OECD (2006). The report clearly stated the urgent need for developing new countermeasures against risky driving behaviour among young drivers. In the present paper the usefulness of countermeasures based on mental elaboration as a means to increase traffic safety are investigated empirically. Studies from areas other than traffic psychology have shown that personal mental elaboration (i.e., reflective thinking on an issue) can be a powerful agent behind changes in attitudes as well as in behaviour (Petty et al., 1995). However, methods explicitly building on mental elaboration have not been

∗ Tel.: +46 8 163935. E-mail address: [email protected]. 0001-4575/$ – see front matter © 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.aap.2009.08.003

tested extensively in traffic safety contexts, although such methods have been considered a promising way to influence young drivers (Engström et al., 2003). Research on the relationship between mental elaboration and attitude and/or behaviour change has used different methods for inducing elaboration. Some of the research concerns changes obtained without interference of any specific persuasive message or request for a change. One such line of research has focused on the effects of unprompted reflection, i.e., instructing a person to reflect on an issue but without any instructions as to how. Unprompted reflection can both influence and polarize previously held attitudes (Tesser et al., 1995). To exemplify, in a study by Richard et al. (1996), changes in both attitudes and behaviour towards condom use were accomplished after participants had been asked seemingly unobtrusive questions about how they anticipated they would feel after having had unprotected sex with a stranger. More specifically, it has also been established that simply questioning people about a specific behaviour may influence their future attitudes as well as actual behaviour—a phenomenon recently named the question-behaviour effect (Sprott et al., 2006). The origin of the studies presented in this article was an unexpected finding in a study by Falk and Montgomery (2009). In an attempt to explore the potential of mental elaboration as a means to increase traffic safety, Falk and Montgomery (2009) tested the effects of an intervention aimed at making young men elaborate on the issue of personal negative consequences of risky driving behaviour. Effects on attitudes were measured using six

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scales regarding attitudes towards risk-taking and accidents in traffic, effects on behaviour were measured using a scale regarding self-reported risky driving behaviour. Although the experimental groups reported attitudes less indicative of risk-taking immediately after the intervention as compared to the control group, no differences in attitudes between the groups remained at a followup some five weeks later. However, this result was at least partly due to the fact that the attitudes of the control group had become less indicative of risk-taking at follow-up, that is, approaching those of the experimental groups. Regarding self-reported risky driving behaviour no effect of the intervention as such could be found; there were no significant differences between conditions neither before the intervention nor at the follow-up. However, the study also revealed an unexpected finding. All three groups, the control group as well as the two experimental groups, reported less risk-taking behaviour at follow-up than they did before the intervention. The change in self-reported driving behaviour was significant (p < 0.001) with partial 2 = .18. This was a surprising result, not easily explainable at first sight. However, when set in connection to the question-behaviour effect (Sprott et al., 2006) it made more sense. Could it be that simply responding to items in the questionnaire had affected the participants’ subsequent self-reported driving behaviour? On the definition of the question-behaviour effect, Sprott et al. (2006) wrote the following: “. . .we encourage the use of the label question-behavior effect to describe any phenomenon whereby questioning of a person (whether it be through an intention measure, self-prediction, a measure of satisfaction, or other means) influences the future performance of the focal behaviour.” (p. 129) A practical aspect of the question-behaviour effect, particularly relevant to research on accident prevention methods in traffic psychology, also deserves to be mentioned. At present, the most prevalent way to collect data on driving behaviour and on attitudes related to driving is by means of self-report questionnaires. The validity as well as the test-retest reliability has been found satisfactory at least for the Driver Behaviour Questionnaire (DBQ), which is one of the most commonly used scales for measuring driving behaviour (Sundström, 2008). If, as the research discussed above indicates, the sheer measurement of self-reported driving behaviour functions as an intervention per se, this would indicate some serious methodological problems concerning the use of self-report measures for studying effects of safety interventions. The main aim of the present study is twofold: (a) to investigate whether answering a questionnaire regarding personal driving habits and attitudes can lead to a self-reported decrease in risky driving behaviour and (b) if so, to explore conceivable triggering factors behind the decrease. A second aim is to further investigate the appropriateness of self-reports on driving behaviour as a means to measure the effects of safety interventions in study designs building on pretest-posttest measurement. First, Study I was conducted in order to replicate the results of the study by Falk and Montgomery (2009) and to rule out the possibility that procedural confounders, described below, could have affected the results. Secondly, Study II was conducted to explore if specific components of the questionnaire could have stimulated the decrease in self-reported risky driving.

2. Study I The main aim of Study I was to replicate and substantiate the changes in self-reported risky driving behaviour and attitudes found in the study by Falk and Montgomery (2009). In that study some possible confounds were identified. All participants (control as well as experimental) had partaken in an interview conducted

by a member of the research team and this interview could have stimulated social demand characteristics and caused the decrease in self-reported risky driving behaviour in the follow-up questionnaire. Another factor that could have influenced responses to the follow-up questionnaire was that the initial questionnaire was completed either at a regiment where the participant was doing his military service, or in an office of Swedish National Service Administration when enrolling for compulsory military service. The follow-up questionnaire, on the other hand, was sent by mail to the participants’ home address and was most likely completed in his home. The different contexts could have caused the changes in self-reported risky driving behaviour, due to conceivable implicit or explicit peer pressure in the context of doing (or enrolling for) military service regarding the initial questionnaire, and conceivable influence from family members (e.g., mother and/or father) regarding the follow-up questionnaire. Unpredictable external factors, like seasonal changes in road conditions, safety campaigns, or media coverage, could also have affected follow-up responses. More specifically, Study I had a threefold aim: (a) To investigate if the change in self-reported risk-taking behaviour from initial to follow-up measurement, obtained in the study by Falk and Montgomery (2009), could be replicated without the impact of any intervention or contact with researchers. (b) To control for the other possible confounds mentioned above. (c) To investigate whether attitudes related to risk-taking in traffic would change over time similar to the control group in the study by Falk and Montgomery (2009). 2.1. Method 2.1.1. Participants A total of 193 males with a driver’s licence volunteered to participate in the study and 142 completed it satisfactorily. Seventy-five percent had had their licence for six months or less. Regarding age, 113 (79.6%) were 18 years old, 28 (19.7%) were 19 years of age and one (0.7%) was 20 years old. All participants were recruited on the day they were enrolled for compulsory military service. In Sweden a driver’s licence can be held from age 18 which is also the age of enrolment. 2.1.2. Procedure The participants were recruited by the staff at the same enrolment centres as participants in the study by Falk and Montgomery (2009). Information about the purpose of the study was read by the staff at the information meeting which initiated the enrolment process and was explained as “part of a project aimed at finding methods for decreasing traffic accidents among young people”, and then enlistees with a driver’s licence were asked to volunteer. Participants were assigned to one of three conditions. In condition (1) “Enrolment–Home” (EH) the initial questionnaire was completed at the enrolment centre and the follow-up questionnaire at home, in conformity with the questionnaire administration in the study by Falk and Montgomery (2009). In condition (2) “Home–Home” (HH) both the initial and the follow-up questionnaire were completed at home. The follow-up questionnaire was administered approximately four weeks after the initial questionnaire, in conformity with the study by Falk and Montgomery (2009). Condition (3), “Sole questionnaire” (S), only completed the initial questionnaire which was sent to these participants’ home at the same point in time that the follow-up questionnaire was sent to participants in the other two conditions. The purpose of condition S was to control for the influence of external factors on conditions EH and HH from completion of the initial questionnaire until completion of the follow-up questionnaire. In order to avoid carry-over effects due to discussions between participants in different conditions, the staff at the enrolment cen-

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Fig. 1. Study design. Phases and measures used in the study.

tres was instructed to assign all participants on a certain day to the same condition, either EH, HH or S. Recruitment of participants started with participants in the HH and EH conditions. Participants in the S condition (who received only one questionnaire) were recruited at the end in order to avoid a long delay between signing up for the study and actually receiving the questionnaire, as participants in condition S were to receive their questionnaire simultaneously to when participants in condition EH and HH received their follow-up questionnaire. After volunteering, participants were given brief written information about the study and the nature of their task (regarding conditions EH and HH to complete two questionnaires, regarding condition S to complete one questionnaire). Confidentiality was assured and measures to secure this were explained. Participants were informed that they had the right to end their participation at any time. In return for their participation, they were offered two cinema tickets. A similar brief written description of the study also accompanied the initial questionnaire. The initial questionnaire was distributed to participants in condition EH by the staff at the enrolment centres. When completed it was put into a sealed envelope together with a separate form for name, address, and telephone number. The envelopes were then forwarded to the researcher by the staff. Participants in conditions HH and S were merely asked to write their name, address, and telephone number on forms which were forwarded to the researcher, who then sent the questionnaire(s) to the participants’ home address. The followup questionnaire was administered to the participants in the HH and EH conditions approximately four weeks after they had completed the initial questionnaire. As mentioned above, participants in condition S only received the initial questionnaire, at the same point in time that participants in the other two conditions were sent the follow-up questionnaire. A pre-paid envelope for returning the questionnaire was enclosed. An overview of the study design is found in Fig. 1. If a participant had not returned the questionnaire after about two weeks he was reminded to do so by telephone and if the questionnaire was not returned after two such reminders he was considered a drop-out. Data was collected at the same period of the year as in the study by Falk and Montgomery (2009), that is, starting in October one year later.

2.1.3. Measures The questionnaires used were identical to those used in the study by Falk and Montgomery (2009). The initial questionnaire consisted of questions about behaviour and attitudes related to risky driving. It was composed partly of previously validated scales, partly of scales constructed specifically for the Falk and Montgomery study (2009). The questionnaire also included items

regarding demographics and previous personal experiences of driving and accidents. The follow-up questionnaire included the same behaviour and attitude scales as the initial questionnaire. Questions about accident and driving experience during the past four weeks were added. The scale measuring driving behaviour, the “Risky Driving Behaviour scale”, was composed partly of items from the “violations” factor in the Swedish version of the Swedish Driving Behaviour Questionnaire (DBQ-SWE, Åberg and Rimmö, 1998), and partly of items developed and used in a study by Ulleberg and Rundmo (2002). The participant was asked to indicate how often (on a Likert-type response scale with end points 1 = never to 5 = very often) he committed 21 different violations of traffic rules. Attitudes towards risk-taking behaviour were measured by three scales, developed and validated by Ulleberg and Rundmo (2002). The three scales were: “Speeding” (5 items), “Funriding” (3 items) and “Traffic Flow vs. Rule Obedience” (9 items). Attitudes towards accidents and injuries in traffic were measured by four scales. “Risk of Accidents” (3 items) was constructed and validated by Ulleberg and Rundmo (2002). “Injury Reflection” (3 items) was constructed specifically for the study by Falk and Montgomery (2009) and contained items regarding reflection on possibilities of hurting oneself or others in traffic. The third scale, “Concern about Hurting Others” (5 items) was based on a scale developed by Ulleberg and Rundmo (2002) to which two other items were added. Items on these attitude scales were rated on a Likert-type five-point scale with the terminal points 1 = ‘Completely disagree’ and 5 = ‘Totally agree’. The fourth scale “Subjective probability of accidents or mishaps in traffic” (5 items) was also constructed specifically for the study by Falk and Montgomery (2009). It was composed of questions regarding the subjective probability of accidents or mishaps in traffic during the next three years: a collision, oneself being injured, injuring someone else, one’s friend/family being injured, and being caught speeding. These items were rated on a five-point scale with the terminal points 1 = ‘Totally unlikely’ and 5 = ‘Very likely’. A full description of the scales and items can be found in the Appendix.

2.2. Results In total, 146 participants (76%) returned the questionnaire(s). In condition EH 53 out of 67 participants (79%) returned both questionnaires, in condition HH 44 of 63 participants (70%) returned both questionnaires and in condition S 49 of 63 participants (78%) returned the one questionnaire they received. Of these, four (one in condition EH and S respectively and two in condition HH) were removed due to an incomplete questionnaire or an invalid response pattern like responding “3” to all questions. Thus, 142 participants

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completed the study satisfactorily. One-way ANOVAs revealed no significant differences between conditions concerning age, domicile (rural, small town or urban), mileage driven, time with a licence or accident experience. The significance level for all analyses in the present study was set at 5%. 2.2.1. Self-reported risky driving behaviour at initial and follow-up measurement To examine whether there was a change in self-reported risky driving behaviour at the follow-up measurement as compared to the initial measurement, a factorial 2 (time: initial measurement, follow-up) × 2 (condition: EH, HH) repeated measures ANOVA was conducted. The Risky Driving Behaviour scale (Cronbach’s ˛ = .88) was the dependent variable.1 Means (standard deviations in parentheses) for the initial questionnaire were 2.18 (0.464) for condition HH and 2.26 (0.547) for condition EH. For the follow-up questionnaire means were 2.00 (0.508) for HH and 2.05 (0.466) for EH. There was a main effect of time, F(1, 91) = 16.16; p < 0.001, partial 2 = .15, showing a decrease in self-reported risky driving behaviour at follow-up. There were no significant differences between conditions, either regarding the initial questionnaire or at follow-up. Nor was there any significant interaction between condition and time. Thus, the decrease in self-reported risky driving behaviour found in the study by Falk and Montgomery (2009) was replicated and the results indicate no effects due to different contexts when filling out the initial questionnaire (at the enrolment centre or at home). The decrease occurred without any intervention or personal contact with a researcher. 2.2.2. Role of external factors for the decrease in self-reported risky driving behaviour The influence, if any, of potential unforeseen external factors on the decrease in self-reported risky driving behaviour was checked by means of participants in condition S who only answered the questionnaire once; at about the same time as when participants in the other two conditions answered the follow-up questionnaire. A one-way ANOVA across the three conditions at initial measurement revealed no significant differences between the scores on the Risky Driving Behaviour scale for the participants in either of conditions EH, HH and S, F(2, 138) = .313, p = 0.732. However, a t test revealed a significant difference, t(138) = −2.0, p = 0.047, between the followup scores on the Risky Driving Behaviour scale for conditions EH and HH vs. the scores for condition S. This contradicts the possibility that the decrease in self-reported risky driving behaviour could be due to the influence of external factors. Fig. 2 displays scores on the Risky Driving Behaviour scale for the three groups. 2.2.3. Attitudes towards risk-taking at initial and follow-up measurement Mean scores on the seven attitude scales at the initial measurement and at follow-up are displayed in Table 1, where Cronbach’s alpha values for the scales are also displayed. As the reliability of the scale Risk of Accidents was considered non-satisfactory (˛ = .54) it was excluded from further analyses. The reliability of another scale, Funriding (˛ = .66), was also rather low, but as the scale consisted of only three items and the average inter-item correlation was .40 it was decided to keep it. The reliabilities of the other scales were considered satisfactory, with ␣-scores ranging from .70 to .81.

1 A factor analysis (principal component analysis, oblique rotation) revealed that the Risky Driving Behaviour scale actually consisted of four dimensions. As repeated measures ANOVAs for each dimension respectively showed the same pattern as for the scale as a whole, that is, a significant decrease in risk-taking behaviour for all groups, it was decided that the full scale would be used.

Fig. 2. Means of scores on the Risky Driving Behaviour scale for the three conditions. High scores indicate risky driving behaviour. Note that the questionnaire was only administered once to condition S, at a point in time corresponding to the administration of the follow-up questionnaire to conditions EH and HH.

A doubly multivariate analysis of variance was conducted to investigate whether attitudes changed from initial measurement to follow-up. Independent variables were time (initial measurement and follow-up) and condition (HH and EH). The six attitude scales; Speeding, Traffic flow vs. Rule Obedience, Funriding, Concern about Hurting Others, Injury Reflection and Subjective Probability of Accidents were dependent variables. There was a significant main effect of time, F(6, 85) = 8.37 p < 0.001; Wilks’ Lambda = .628, on the combined attitude variable.2 There were no main effects of condition. Separate t-tests showed no significant differences in attitudes between conditions at the initial measurement. Thus the context (at the enrolment centre or at home) for filling out the initial questionnaire had no significant effect on attitude scores. To inspect the effects of time for each separate attitude scale, tests of within-subjects contrasts were carried out. There was a significant main effect of time for three of the scales; Concern about Hurting Others, F(1) = 11.57, p < 0.001, Subjective Probability of Accidents, F(1) = 8.64, p = 0.004, and Injury Reflection, F(1) = 8.42, p = 0.005, meaning that participants expressed more concern about hurting others, experienced a higher subjective probability of accidents, but thought less about injuries at follow-up. The changes in scale means are displayed in Table 1. However, the analysis also indicated a significant interaction between condition and time, F(6, 85) = 2.6, p = 0.020; Wilks’ Lambda = .841. Tests of within-subjects contrasts revealed that the interaction was significant only for the Traffic Flow vs. Rule Obedience scale (p = 0.04), where the two conditions went in different directions at follow-up, condition HH showing “riskier” and condition EH showing “safer” attitudes over time. 2.3. Discussion The decrease in self-reported risky driving behaviour at followup, found in the study by Falk and Montgomery (2009), was replicated, and the decrease was independent of any specific intervention or person-to-person contact with the researchers. Nor did the context when answering the initial questionnaire (at the enrolment office vs. at home) or conceivable external factors have any effect on the way the participants reported their driving habits at

2 Here MANOVA was used to analyze whether a linear combination of the six attitude scales (the combined attitude variable) varies as a function of condition and/or time. MANOVA protects against Type I error as a result of doing separate repeated-measures ANOVAS on several dependent variables. See Tabachnick and Fidell (2001) for a full description of this variety of MANOVA.

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Table 1 Cronbach’s alpha, means and standard deviations (in parentheses) for the seven attitude scales over condition and time. Initial questionnaire

Follow-up questionnaire

Scale

˛

HH (Home–Home)

EH (Enrolment–Home)

HH (Home–Home)

EH (Enrolment–Home)

Flow, 9 items Funride, 3 items Injury reflection, 3 items Speed, 5 items Concern, 5 items Subj prob. of accident, 6 items Risk for accidents, 3 items*

.80 .66 .71 .81 .70 .77 .54

2.68 (0.63) 2.83 (1.05) 3.06 (0.82) 2.60 (0.91) 1.80 (0.70) 2.37 (0.56) 1.44 (0.47)

2.71 (0.68) 2.71 (1.02) 2.97 (1.0) 2.69 (0.85) 1.88 (0.80) 2.45 (0.63) 1.81 (0.80)

2.54 (0.73) 2.55 (0.97) 3.20 (0.94) 2.64 (0.96) 1.63 (0.64) 2.63 (0.73) 1.45 (0.49)

2.83 (0.69) 2.64 (1.15) 3.30 (1.05) 2.69 (0.85) 1.58 (0.75) 2.59 (0.58) 1.51 (0.58)

Note: Range 1–5. High scores indicate more risk-taking attitudes and less distress over accidents and injuries, except on the Subjective Probability of Accidents scale where, on the contrary, high scores indicate a belief that accidents might befall oneself. * The scale Risk for accidents was excluded from analysis due to low reliability.

follow-up. There was also a change over time in attitudes relating to accidents and injuries in traffic. Participants, irrespective of condition, claimed to be more concerned about the possibility of hurting someone else in traffic, judged the subjective probability of an accident as higher but thought less about injuries at follow-up than they did at initial measurement. The latter results are seemingly inconsistent and difficult to explain. It would seem more logical if participants had reported thinking more about injuries as well. An inspection of scores on individual items in the three scales gave no clues as to conceivable reasons behind this result. One tentative explanation would be that answering the initial questionnaire made participants realize that they actually did not think much in terms of the possibility to injure someone else or themselves in traffic, or of the probability of having an accident. In order to further explore potential factors that could explain the decrease in self-reported risky driving behaviour, a second study was carried out.

risk-taking behaviour. That such discrepancies may evoke cognitive dissonance and motivate changes in behaviour or attitudes has been shown in a large number of previous studies (for an overview see, e.g., Olson and Stone, 2005). The third version of the questionnaire, condition “Attitudes to Accidents” (AccAtt), consisted of the Risky Driving Behaviour scale plus four scales regarding attitudes towards accidents and injury in traffic (Risk of Accidents, Concern about Hurting Others, Injury Reflection and Subjective Accident Probability). The scales comprised a total of 16 items (see Appendix). The rationale behind using this version was that questions about consequences of risky driving behaviour might raise the participants’ awareness of negative affective consequences of risky driving, and thus motivate decreased risk-taking. This would be in line with the results from the study by Richard et al. (1996) who found effects on attitudes as well as behaviour by raising awareness of the negative affective consequences of unsafe sex. 3.1. Method

3. Study II The results from Study I in combination with the results from the study by Falk and Montgomery (2009) indicate a questionbehaviour effect (Sprott et al., 2006) resulting from completing a questionnaire about behaviour and attitudes related to risky driving. Study II was conducted to explore if specific parts of the questionnaire could have stimulated the decrease in self-reported risky driving. The aim was to investigate whether the change in selfreported risky driving behaviour found in Study I would be elicited by simply asking questions about personal driving behaviour, or whether additional questions about attitudes relating to risky driving were needed to obtain it. In order to accomplish this aim, I used three different versions of the initial questionnaire and studied their effects on the Risky Driving Behaviour scale at followup. Each version corresponded to an experimental condition, as described below. In order to confine the effects of answering the initial questionnaire to self-reported risky driving behaviour, no attitude questions were asked at follow-up. The first version of the initial questionnaire, condition “Driving Behaviour Only” (DBO), consisted of only the Risky Driving Behaviour scale, that is, questions about personal driving behaviour. The second version of the questionnaire, condition “Attitudes to Risk Taking” (RiskAtt), consisted of the Risky Driving Behaviour scale plus the three scales regarding attitudes towards various risk-taking behaviours in traffic (Speeding, Funriding and Traffic Flow vs. Rule Obedience). The scales comprised 17 items in total (see Appendix). The rationale behind studying the impact, if any, of this version was as follows: As a consequence of being exposed to questions about actual personal risky driving behaviour as well as questions about his attitudes towards similar behaviour, the participant may become aware of discrepancies between his attitudes and his behaviour. This, in turn, might lead to a change in self-reported

3.1.1. Participants A total of 149 male participants signed up for participation in the study. Of these 94.6% (141 participants) were 18 years old and 5.4% (8 participants) were 19 years old at the time of the study. All had a driver’s licence, 92.4% had had their licence for six months or less, 5.3% had had it between 7 months and one year and three persons (2.3%) had had it for more than one year. Two participants did not state their time with a licence, but as 18 is the licensing age in Sweden they could not have had their licence for more than two years. Like in Study I participants were recruited on the day they were enrolled for compulsory military service. 3.1.2. Material The initial questionnaire given to the participants differed according to condition, as described above. All participants were also given questions about demographics, amount of driving, and personal accident experience The follow-up questionnaire was identical for all three conditions. It contained questions about personal driving and accident experience during the past four weeks and the Risky Driving Behaviour scale. In contrast with Study I no attitude scales were included in the follow-up questionnaire, as mentioned above. 3.1.3. Procedure The participants were recruited by personnel at one office of the Swedish National Service Administration. Information about the purpose of the study was read by the staff at the information meeting that initiated the enrolment process and was explained as “a part of a project aimed at finding methods for decreasing traffic accidents among young people”. Thereafter enlistees with a driver’s licence were asked to volunteer. For practical reasons and in order to avoid carry-over effects due to discussions between participants in different conditions, the staff at the enrolment cen-

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tres was instructed to assign all participants on a certain day to the same condition (either DBO, RiskAtt or AccAtt, as described above) and to alternate the three conditions. Unfortunately, it turned out that the staff at the enrolment centre had not entirely followed these instructions when administering the questionnaires. Instead of administering the first questionnaire in parallel to the three conditions, it was distributed to most participants in condition DBO in the beginning of the data collection period, to condition RiskAtt thereafter and to condition AccAtt at the end of the period. At the time the Swedish National Service Administration was going through a major reorganization, including downsizing, which probably affected the data collection. After volunteering, participants were given brief written information about the study (“a part of a project aimed at finding methods for decreasing traffic accidents among young people”) and the nature of their task (“to complete one questionnaire on the present day and another questionnaire about a month later”). Participants were informed that they had the right to terminate participation at any time and were offered two cinema tickets in return for completing the follow-up questionnaire. Confidentiality was assured and measures to secure this were explained. The completed initial questionnaire, together with a separate sheet for name, address and phone number, was put into a sealed envelope by the participant. The envelopes were then forwarded to the researcher by the staff. The follow-up questionnaire, together with a pre-paid envelope for returning it, was sent to the participant’s home address some four to five weeks after completion of the initial questionnaire. If a participant had not returned the follow-up questionnaire after about two weeks he was reminded to do so by telephone and if the questionnaire was not returned after two such reminders he was considered a drop-out. Data were collected at the same period of the year as in Study I, that is, starting in October one year later. 3.2. Results In all 134 out of a total of 149 participants (90%) completed both the initial and the follow-up questionnaire. Of these, one in condition AccAtt was removed due to an incomplete questionnaire. In condition DBO 46 out of 50 participants (92%) completed both questionnaires, in condition RiskAtt 46 of 51 participants (90%), and in condition AccAtt 41 out of 48 participants (85%). The change from the originally planned distribution of the questionnaires, mentioned above, did not result in any significant differences between conditions regarding the background variables mileage driven, time with a licence, accident experience and age. However, regarding domicile participants in DBO were more likely to live in the provinces whereas participants in AccAtt were more likely to live in large cities, 2 (1) = 6.56, p = 0.01. In order to examine whether the contents of the initial questionnaire influenced self-reported risky driving behaviour at follow-up, a 2 (time: initial questionnaire, follow-up questionnaire) × 3 (condition: DBO, RiskAtt, AccAtt) repeated measures ANOVA was conducted. The Risky Driving Behaviour scale was the dependent variable. Significance level was set to ˛ = .05. There was a main effect of time, F(1, 128) = 35.76; p < 0.001, even greater than in Study 1 (partial 2 = .22). Separate one-way repeated measures ANOVAs showed that the reported decrease in risky driving behaviour from the initial questionnaire to the follow-up questionnaire was significant for all three conditions at p = 0.001.3

3 As homogeneity of variance and normality for the samples were not completely satisfactory I checked these results by means of the non-parametric Wilcoxon Signed Rank Test. In this analysis as well the main effect of time and the changes in scores for each of the conditions were significant with p < .01.

Fig. 3. Means of scores on the Risky Driving Behaviour scale at the initial and the follow-up questionnaire for the three conditions. High scores indicate risky driving behaviour.

However, there was also a significant overall difference, F(2, 128) = 5.25; p = 0.006, between conditions on the Risky Driving Behaviour scale, as can be seen in Fig. 3 below. The effect size was not very large (partial 2 = .08) and pairwise comparisons (Bonferroni correction) revealed that the difference was significant only for condition DBO vs. condition RiskAtt. For these two conditions the effect was significant for the initial questionnaire as well as for the main effect of time. Concerning the follow-up questionnaire, there were no significant differences on the Risky Driving Behaviour scale between any of the conditions. 3.3. Discussion Study II was conducted to explore if specific components of the questionnaire could have caused the decrease in self-reported risky driving. However, the decrease in self-reported risky driving behaviour in Study I was replicated and was significant for all three conditions, that is, regardless of the content of the initial questionnaire. Thus, the change in self-reported risky driving behaviour was produced by just asking questions about personal driving behaviour. Additional questions about attitudes relating to risky driving did not add significantly to the effect. The comparatively high score on the Risky Driving Behaviour scale on the initial questionnaire for the DBO condition deserves to be discussed. There were no differences in time with a licence, personal accident experiences or mileage driven that could explain the discrepancy. The only difference between conditions was place of domicile, but analyses revealed no general differences between urban and provincial participants regarding driving behaviour. One possible explanation could be that, in conditions RiskAtt and AccAtt, the attitude questions influenced the response to the behavioural questions on the initial questionnaire. I find this explanation less likely as the attitude questions were posed after the behavioural questions. However, if participants browsed through the questionnaire as a whole before answering it, the attitude questions could have influenced responses to the behavioural questions. Schwarz and Hippler (1995) have shown that regarding selfadministered questionnaires subsequent questions can influence preceding questions as respondents may go back and forth between questions. Nevertheless, whatever the reason for the high scores of condition DBO on the Risky Driving Behaviour scale, it does not obscure the fact that in all three conditions the scores had changed in the expected direction at follow-up. It is worth pointing out that the sample ought to be quite representative of Swedish 18–19-year-old men with a driver’s licence. Most young men in Sweden went through the enrolment procedure at the time of the studies and according to the staff at the enrolment

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centres, most enlistees with a driver’s licence volunteered for the study. 4. General discussion and conclusion The decrease in self-reported risky driving behaviour at followup, found in the study by Falk and Montgomery (2009), was replicated and substantiated in the present Study I and Study II. Thus, the two studies presented in this article show that answering questions regarding personal risky driving behaviour leads to a self-reported decrease in risky driving behaviour about one month later. This is a robust finding, further supported by the findings reported by Falk and Montgomery (2009). A stock answer as to why the decrease in self-reported risky driving behaviour occurred would be to refer to various effects of repeated measurement, like instrumentation bias (Campbell et al., 1963). The phenomenon is not uncommon in research on the effects of various psychosocial interventions, often within a clinical psychiatric context, and refers to a tendency for respondents in the control group as well as in the experimental group to report more well-being or fewer symptoms when retested (Arrindell, 2001; Durham et al., 2002; Fendrich and Yun Soo Kim, 2001; Longwell and Truax, 2005; Stice et al., 2001). In his article on unresolved issues in measurement validity Campbell (1996) discusses the phenomenon in terms of “measurement as persuasion”. Although a number of explanations regarding possible causes behind the phenomenon have been proposed, the picture of its nature is still far from clear (for discussions and overviews see, e.g., Arrindell, 2001; Knowles et al., 1996). In the present context the decrease in self-reported risky driving behaviour will be discussed in terms of a question-behaviour effect. In the literature two major approaches to the questionbehaviour effect (Sprott et al., 2006) are found, self-prophecy and mere-measurement. In studies on the self-prophecy effect (e.g., Spangenberg and Greenwald, 1999) the issue is to make a prediction about one’s future behaviour. In that approach the proposed explanation for the question-behaviour effect is that answering such questions may evoke cognitive dissonance. Experiments have shown that cognitive dissonance, evoked by being faced with discrepancies between ones attitudes and actual behaviour can be a force behind change (e.g., Aronson et al., 1991). However, in the present study adding questions regarding attitudes towards risky driving behaviours had no extra effect on the responses on the Risky Driving Behaviour scale in the follow-up measurement. The mere-measurement research approach has proposed the explanation that answering questions regarding intent to perform a specific behaviour raises the accessibility of attitudes and beliefs related to the behaviour in question (e.g., Morwitz and Fitzsimons, 2004). In the present study no questions about intent were asked, but an attempt to raise awareness of negative outcomes of risky driving by means of accident-related attitude questions in the initial questionnaire was made. This, however, had no effect on the responses on the Risky Driving Behaviour scale in the followup measurement. Nevertheless, from my point of view increased accessibility of attitudes and beliefs as an effect of answering questions about personal driving behaviour constitutes the most likely explanation of the decrease in self-reported risky driving behaviour. Answering questions in a questionnaire requires accessing and scrutinizing issue-relevant internal knowledge (e.g., “How often do I drive too close to the car in front?”). Previous research has shown that merely thinking about an issue tends to make evaluations connected to it more extreme, accessible and stable (Tesser et al., 1995). One reason may be that thinking changes the cognitive representation related to the issue (Valenti and Tesser, 1981) and affects the structure of attitudes and beliefs (Millar and Tesser, 1986). From a somewhat different point of view, Feldman and

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Lynch (1988, p. 423) propose that answering surveys may bring previously non-thought of behaviours into conscious awareness and suggest: “The researchers survey causes [respondents] to focus attention on outcomes as described in the questionnaire, to form overall evaluations of alternative courses of action, and to state a behavioural intention. It is not unlikely that the entire sequence of questioning serves as the basis for attitude formation, which then serves as the most salient basis for the development of an intention.” Fishbein et al. (1980) argued that changing underlying beliefs, or making certain beliefs more salient, should lead to changes in attitudes, thereby influencing intention and possibly behaviour. According to Ajzen and Fishbein (2005) intention to perform the behaviour in question is the major determinant of volitional behaviour. Recently, Ajzen and Fishbein (2005) pointed out that the accessibility of beliefs is important for the relationship between attitudes, intentions and behaviour—more accessible beliefs lead to a stronger link between attitudes and behaviour. This is in line with Fazio (1995), who points out the importance of attitude accessibility for attitude-behaviour consistency. It is quite likely that a process involving belief and attitude activation occurred in the minds of participants in the present studies. Using the analogy of an inner dialogue when answering the first questionnaire, the process could be verbalized as: “Do I often overtake the car in front when it is driving at the speed limit? Well, it does happen. 5 means very often, 1 means never – so I’ll set my mark at 3. Hmmm. Overtaking a car driving at the speed limit is really not a very good thing to do. I really shouldn’t do it anymore.” Taken together, assuming that most young male drivers essentially disapprove of traffic violations (like those portrayed in the items of the Risky Driving Behaviour scale) and want to drive correctly, answering the questionnaire could have made such beliefs more salient and led to more accessible and polarized attitudes about the issue. This in turn could have influenced intention to obey traffic rules to a greater extent, resulting in respondents reporting a less risky driving behaviour at follow-up. This interpretation of the reasons for the reported decrease in risky driving behaviour is necessarily speculative as the research on the signification of the effects of answering questions is still in its infancy. However, as a possible means to prevent traffic accidents it does merit further investigation. Some other aspects of the results also deserve to be commented on. The first and perhaps most important one is whether the decrease in self-reported risky driving mirrors a safer actual driving behaviour. To study the effects of interventions by means of accident statistics necessarily involves a very large number of drivers in order to achieve sufficient statistical power. But, considering the relative ease with which an instrument like the Risky Driving Behaviour scale could be employed, such a validation study would be possible to conduct and important for future research. However, several studies have found self-reports of driving behaviour being predictive of accidents (e.g., Hatakka, 1998; Iversen and Rundmo, 2004; Parker et al., 1995a,b; Ulleberg, 2001) as well as being in fair agreement with observed behaviour (Lajunen and Summala, 2003). Another question that may be raised by the results is whether they simply reflect socially desirable responding. In the present context a social desirability effect would likely result from a need to create a positive image of oneself as a driver, responding to perceived expectations from the researcher. This need for positive self-presentation could be reflected in reporting less risky driving behaviour at follow-up than was initially reported. Although no items to detect tendencies for socially desirable responding were used in the study, I argue that the decrease in risky driving behaviour could not be explained by this kind of response bias.

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First, a previous study (Falk and Montgomery, 2007) indicates that behaviours like speeding, running yellow lights, illegal parking, etc., are not connected to any fear of negative self-presentation. Such behaviours were readily admitted by respondents in that study and they perceived fast and rather “aggressive” driving behaviour as standard behaviour among young men. Socially desirable responding is most common when there are strong social norms attached to the surveyed issue (e.g., Razavi, 2001). Second, in the study by Falk and Montgomery (2009) a need for self-presentation as a responsible driver should have been more appropriate when answering the Risky Driving Behaviour scale the first time, prior to a personal meeting with a researcher interested in traffic safety. Another result that disconfirms social desirability as an explanation for the reported decrease in risky driving behaviour is the tendency to report thinking less of the possibility of injuries in traffic at follow-up in the present Study I. If respondents had felt the need to present themselves positively to a researcher interested in traffic safety, it seems likely that they would report thinking more of injuries. Furthermore, Lajunen and Summala (2003) found only minor effects of social desirability on Driver Behaviour Questionnaire (DBQ) scores in a study specifically designed to explore its impact. 4.1. Conclusions From an applied accident prevention viewpoint there are two conclusions to be drawn from the present study. The first conclusion is that if asking questions about behaviour has the power to alter that which is measured, there is a need to develop alternative instruments for evaluating effects of experimental traffic safety interventions on attitudes and behaviour. It is not unreasonable to infer that the self-report measure of risky driving behaviour, used in the present studies, actually served as an intervention in itself. This would pose a serious threat to the validity and reliability of self-report measures as a means to evaluate the effects of safety interventions. A look into recent research reveals that new technology now enables us to use other types of instruments than self-reports for measuring driver behaviour and attitudes. There have been promising attempts to measure driver behaviour using video or Internet-based methods (Horswill and Coster, 2001; Horswill and McKenna, 1999). Another recent approach (Hatfield et al., 2008) is the use of the Implicit Association Test to measure implicit attitudes to driving, likely circumventing response bias like socially desirable responding. Instrumented cars have also been used successfully in studies of different types of driver behaviour (e.g., Glendon, 2007; Patten et al., 2004). Lastly, ISA (Intelligent Speed Adaptation) devices have recently been used successfully to measure drivers’ speeding behaviour in a number of studies (see Wallén Warner, 2006, for a review) and could be used to measure the effects of preventive interventions directed at speeding. Such new measures may become valuable instruments also in intervention evaluation contexts, possibly averting some of the drawbacks of self-reports. One way to further explore the mechanisms behind the reported decrease in risky driving behaviour in the present investigation would be to compare repeated measurement of driver behaviour via self-reports with repeated measurement of the same behaviour by means of, for example, video-based methods. The second conclusion bearing on the prevention of traffic accidents is that being stimulated to think about an issue might affect both the belief structure and the attitudes of an individual and make both more accessible, which in turn might influence behaviour. This has been touched on by several authors and from different theoretical angles (e.g., Feldman and Lynch, 1988; Knowles and Condon, 2000; Loken, 2006; Richard et al., 1996; Robinson and Clore, 2002; Wyer and Albarracín, 2005). Research on interventions building on unprompted reflection is still in its infancy. Further research in

order to elucidate the potential of such interventions to increase traffic safety is much needed. Acknowledgements I am grateful to Professors Henry Montgomery and Ola Svenson for valuable comments on earlier versions of this manuscript. Thanks also to the staff at the Swedish National Service Administration who enabled data collection. This research was financed by the Swedish Road Administration and Länsförsäkringars Forskningsstiftelse, none of which was involved in any part of the research process. Appendix A. Scales and scale items used in the study (translated from Swedish) High scores indicate risky behaviour/attitudes except for the Subjective Probability of Accident scale where high scores indicate a belief that accidents might befall oneself. Alpha values are from Study I. Risky Driving Behaviour scale ˛ 0.88 (How often do you. . . 1 = never, 5 = very often) Consciously drive too fast in order to keep up with traffic pace Take over when the car in front slows down in adherence of speed limit Drive too close to car in front to make him move out of the way Drive on a yellow light when it is about to turn red Park illegally when making a short errand Deliberately disregard speed limits on major roads when there is little traffic Deliberately speed when overtaking Park illegally when there is no free parking spot Exceed a speedlimit of 50 km/h with more than 10 km/h Exceed a speed limit of 70 km/h with more than 10 km/h Exceed a speed limit of 90 km/h with more than 10 km/h Drive against red light when no one is around Overtake the car in front when it is driving at the speed limit Drive too close to car in front Drive fast because the opposite sex enjoys it Break traffic rules in order to get ahead Break traffic rules because they are too complicated to follow Break traffic rules due to peer pressure Drive “recklessly” because others expect me to Drive fast to show I am tough enough Drive fast to show others I can handle the car Funriding ˛ 0.66 (1 = do not agree, 5 = completely agree) Speeding and excitement belong together when you are driving Driving is more than transportation, it is also speeding and fun Adolescents have a need for fun and excitement in traffic Speeding ˛ 0.81 It is OK to drive 120 km/h on a 90 km/h road if there are no other cars around It is OK to speed if the traffic conditions allow you to Driving 10–15 km/h over the speed limit is OK because everyone does it It you have good driving skills speeding is OK For a safe driver it is acceptable to exceed the speed limit with 10 km/h on a 70 km/h road Traffic flow vs. rule obedience ˛ 0.80 Sometimes it is necessary to bend the rules to keep traffic going It is better to drive smooth than always follow traffic rules Sometimes it is necessary to bend the traffic rules in order to get ahead Sometimes it is necessary to take chances in traffic

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Sometimes it is necessary to bend traffic rules to arrive in time There are many traffic rules that cannot be obeyed in order to keep up traffic flow It is more important to keep up the traffic flow than always follow the traffic rules Sometimes it is necessary to ignore violations of traffic rules A person who takes chances and violates some traffic rules is not necessarily a less safe driver Injury reflection ˛ 0.71 (all items reverse scored) I often think about the possibility that I could injure someone else in traffic I often think about the possibility that I myself might get hurt in traffic I often think about how horrible it would be if I hurt someone else in traffic Risk of accidents ˛ 0.54 (all items reverse scored), not used in analyses due to low reliability. Drunk driving is not so risky as people think it is The risk of dying young in traffic is so low that you can ignore it Driving off the road accidents are so rare that there is no need to worry Concern for hurting others ˛ 0.70 (all items reverse scored) If I would cause an accident where someone else was hurt it would scar me for life I could not live with myself if I hurt another human being in traffic If I should cause an accident where someone is hurt I hope I am the only one to get hurt It can never be excused to take a person’s or an animal’s life because of careless driving I hope I will never be involved in an accident of which I am the cause Subjective accident probability (1 = unlikely, 5 = very likely) ˛ 0.77 How likely do you think it is that you will be involved in a car crash in the next three years? . . .that you yourself will be hurt in traffic in the next three years? . . .that you will hurt someone else in traffic. . .. . . .that someone you know well will be hurt in traffic. . .. . . .that you will drive off the road. . .. How likely do you think it is that you will be caught speeding in the next three years? References Åberg, L., Rimmö, P., 1998. Dimensions of aberrant driver behaviour. Ergonomics 41 (1), 39–56. Ajzen, I., Fishbein, M., 2005. The influence of attitudes on behavior. In: Albarracin, D., Johnson, B.T., Zanna, M.P. (Eds.), The Handbook of Attitudes. Lawrence Erlbaum Associates, Mahwah, NJ, pp. 173–221. Aronson, E., Fried, C., Stone, J., 1991. Overcoming denial and increasing the intention to use condoms through the induction of hypocrisy. American Journal of Public Health 81 (12), 1636–1638. Arrindell, W.A., 2001. Changes in waiting-list patients over time: data on some commonly-used measures. Beware! Behaviour Research and Therapy 39 (10), 1227–1247. Campbell, D.T., 1996. Unresolved issues in measurement validity: an autobiographical overview. Psychological Assessment 8 (4), 363–368. Campbell, D.T., Stanley, J.C., Gage, N.L., 1963. Experimental and Quasi-Experimental Designs for Research. Houghton, Mifflin and Company, Boston, MA. Durham, C.J., McGrath, L.D., Burlingame, G.M., Schaalje, G.B., Lambert, M.J., Davies, D.R., 2002. The effects of repeated administrations on self-report and parentreport scales. Journal of Psychoeducational Assessment 20 (3), 240–257. Engström, I., Gregersen, N.P., Hernetkoski, K., Keskinen, E., Nyberg, A., 2003. Young novice drivers, driver education and training: Literature review. VTI Report 491A. Linköping, Sweden, VTI. Falk, B., Montgomery, H., 2007. Developing traffic safety interventions from conceptions of risks and accidents. Transportation Research Part F 10 (5), 414–427. Falk, B., Montgomery, H., 2009. Promoting traffic safety among young male drivers by means of elaboration-based interventions. Transportation Research Part F: Traffic Psychology and Behaviour 12, 1–11. Fazio, R.H., 1995. Attitudes as object-evaluation associations: determinants, consequences and correlates of attitude accessibility. In: Petty, R.E., Krosnick, J.A. (Eds.), Attitude Strength: Antecedents and Consequences. Lawrence Erlbaum Associates, Hillsdale, NJ, pp. 247–282.

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