Effects of persuasive communication and group discussions


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Effects of persuasive communication and group discussions

  1. 1. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
  2. 2. Author's personal copy Available online at www.sciencedirect.com Transportation Research Part F 11 (2008) 207–220 www.elsevier.com/locate/trf Effects of persuasive communication and group discussions on acceptability of anti-speeding policies for male and female drivers Charles Goldenbeld *,1, Divera Twisk 2, Sjoerd Houwing 3 Institute for Road Safety Research SWOV, Duindoorn 32, 2262 AR Leidschendam, The Netherlands Received 20 June 2007; received in revised form 2 November 2007; accepted 3 November 2007 Abstract In an experiment on acceptability of anti-speeding interventions, male and female car drivers were randomly assigned to four information conditions: (C1) combination of neutrally toned written communication and fear appeal anti-speeding tvspot, (C2) written communication only, (C3) fear appeal anti-speeding tv-spot only, (C4) neither written communication nor fear appeal tv-spot. It was tested whether a first time exposure to these stimuli would produce changes in the acceptability of a reduction in the speed limit of rural access roads from 80 to 60 km/h, and whether after exposure, acceptability would shift resulting from group discussions about the measure. Results showed that fear appeal had counterproductive effects on male but not on female drivers on three indicators of acceptability. For both genders, group discussion shifted attitude ratings in a negative direction. For females, this effect could partially be reduced by neutrally toned knowledge based information. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Persuasive communication; Acceptability; Speed limit; Attitude; Fear appeal 1. Introduction Persuasive communication is extensively used in traffic safety to influence opinions and beliefs with the objective to improve acceptability of, and social co-operation with, road safety measures and/or programmes. Research into its effects primarily deals with intra-individual processes (e.g. individual cognitions, attitudes, perceived social norm) without taking into account the social process by which these are formed. In contrast, in everyday life persons verify their opinions and attitudes by comparing them with those of relevant others or * Corresponding author. Tel.: +31 (0) 70 3173333; fax: +31 (0) 70 3201261. E-mail addresses: charles.goldenbeld@swov.nl (C. Goldenbeld), divera.twisk@swov.nl (D. Twisk), sjoerd.houwing@swov.nl (S. Houwing). 1 Tel.: +31 (0) 70 3173364. 2 Tel.: +31 (0) 70 3173365. 3 Tel.: +31 (0) 70 3173386. 1369-8478/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.trf.2007.11.001
  3. 3. Author's personal copy 208 C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 reference groups (Suls & Wheeler, 2000). Therefore, in the study of persuasive communication it is of vital importance to understand how the effects stand up to, or combine with, those resulting from everyday social communication. This is particularly relevant if the targeted problems can be characterized as situations in which private interests are at odds with collective interests, and the effectiveness of the measure is dependent on the co-operation of the majority. In these so-called ‘‘social dilemmas’’, persuasive communication may lead to increased problem awareness without having any further effect on the willingness to contribute to the solution, which may well be related to the individual’s assessment of the likely co-operation by others (Klandermans, 1992). In the area of road safety, drivers’ speed choice is an example of a social dilemma. At a collective level speed violations will result in more accidents, whereas at an individual level the driver merely experiences the immediate personal advantages of speeding. This article presents results from an experiment investigating the effects of different types of persuasive communication on the social acceptability of a speed-related safety measure. The exploratory part of the experiment examines to what extent one central indicator of acceptability, namely attitudes towards introduction of a measure, is influenced by informal social communication (e.g. group discussion). The recent introduction of new 60 km/h zones on rural roads in the Netherlands,4 was used as a case entailing elements of a social dilemma. 1.1. Acceptability of speed-related traffic measures Consistent with previous studies, we identified the following factors which together determine the ‘‘social acceptability’’: drivers need to be aware of a problem arising from certain behaviour (e.g. Steg, 2003); appraise an intervention or policy as effective, efficient, just, and likeable (e.g. Bamberg & Rolle, 2002; Ittner, Becker, & ¨ Kals, 2003); and be prepared to conform to the norms or guidelines set forth by the policy or intervention. In this study we measured acceptability of anti-speeding policies in terms of: (1) problem perception with regard to speeding, (2) various attitudinal ratings regarding efficiency and justness of the measure, and (3) intentions to comply with the measure. 1.2. Type of communication and acceptability Research has shown that the different factors comprising acceptability may be influenced differently by informative persuasive communication targeted on attitudes, beliefs and intentions. In the social-psychological literature, change in general attitudes often does not result in similar change in behavioural intentions (e.g. Fishbein & Ajzen, 1975). Although change in attitude may be a necessary condition for change in intentions, by itself it is often not sufficient to bring about the desired change. In the specific area of acceptance of speed reducing measures, campaign evaluations showed non-correspondent findings for different dimensions of acceptability of speed reducing measures and campaigns. For example, the Scottish ‘Foolsspeed’ campaign which was developed on the basis of the Theory of Planned Behaviour, positively influenced attitudes and beliefs (related to danger perception), but did not influence behavioural intentions to speed (Stead, MacKintosh, Tagg, & Eadie, 2002). A Dutch evaluation of an informative 30 km/h-publicity campaign also failed to show any effects on intentions to conform to the speed limit (Feenstra & Gotz, 2002). In view of the above, we ¨ hypothesised that a persuasive, informative anti-speeding communication concerning 60 km/h-zones would improve attitudes regarding speed limits and compliance, but would not change intentions to comply with a new 60 km/h-limit (Hypothesis 1). In addition to offering information about possible benefits of a measure, persuasive communication may go one step further by appealing to emotions. In road safety campaigns, the use of emotional language, portraying emotion-evoking scenes, is regularly used. One type of persuasive communication used in traffic safety campaigns is the so-called ‘‘fear appeal’’. These are persuasive messages in which people are presented with fear arousing risk information to convince them to avoid risk-related behaviour and to adopt protective 4 In the Netherlands, the road safety policy is to change the customary 80 km/h limit on rural access roads with a mixture of slow and fast traffic to a 60 km/h limit provided that the change of limit is compatible with the function and design of the road.
  4. 4. Author's personal copy C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 209 behaviour. Recent reviews concluded that fear arousal may have inhibiting as well as facilitating effects on protective motivation and protective action (Das, 2001; De Vries, Ruiter, & Leegwater, 2002; Ruiter, Abraham, & Kok, 2001). In the first stage of this study, the effects of informative persuasive communication and anti-speeding fear appeal on acceptability of 60 km/h-zones were compared. Given the mixed findings in the literature, no hypotheses regarding the direction of the effects of an anti-speeding fear appeal were developed. 1.3. Gender differences and acceptability of anti-speeding measures In general, male drivers are less safety oriented than female drivers – a difference which manifests itself in higher crash rates, higher levels of offending and risk seeking, and more indifference or negative attitudes towards traffic rules, speed limits, and traffic enforcement (e.g. Cauzard & Quimby, 2000; Laapotti, Keskinen, & Rajalin, 2003; Social Issuers Research Centre, 2004). In view of these findings a stronger safety orientation amongst females is expected in this study, indicated by less self-reported speeding, positive attitudes towards 60 km/h zones, higher problem awareness with regard to speeding, and positive self-reported intentions to comply with the new 60 km/h limit. Based on this, it is hypothesised that persuasive communication aimed at changing attitudes and intentions to speed would meet with more psychological resistance by male than by female respondents and that the persuasive effects of the messages would be less evident for males than for females (Hypothesis 2). 1.4. Social communication In social dilemmas, social communication provides persons with an insight into other road users’ attitudes towards a policy measure. In those cases where social communication lowers an individual’s expectations about the likely co-operation and contributions of others, it is to be expected that the individual will evaluate the measure as less pleasant, efficient, social, etc. In the field of traffic research, findings of some studies highlight possible counterproductive effects of social communication (e.g. Steg, 1996). The second stage of this research focused on the influence of group discussion on changes in attitude. Group discussions on new measures tend to focus on their perceived effectiveness, justness and likeability, and consequently, we studied the effect of group discussion on the developments in these variables. 2. Method 2.1. Recruitment and sample A total of 400 invitation letters were sent to addresses of persons in possession of a valid drivers license. Of these 81 (45 male and 36 female) were elected and offered €50 in payment to participate in the study. The mean age of the participants was 51, which is higher than the average age of Dutch drivers which is 41 years. Comparing levels of education, a higher proportion of respondents in the sample had received a higher education (70% versus 23% nationally). All respondents were residents of the suburban areas close to Den Hague city. It can be assumed that they, like the general Dutch driving population, had ample experience with driving on rural roads since rural roads cover nearly half the total road length in the Netherlands and nearly all trips from city to city include some part of rural road. 2.2. Design The research consisted of two stages. In the first stage of the research, the differential effect of message type was studied by randomly assigning participants to one of four experimental conditions (see Table 1): (C1) combination of neutrally toned leaflet and fear appeal anti-speeding tv-spot; (C2) leaflet only; (C3) fear appeal anti-speeding tv-spot only and (C4) no leaflet and no tv-spot. The main effects and the interactive effects of the two types of persuasive communication and gender were studied on the basis of a 2 · 2 · 2 factorial post-test only, between-subjects design. Gender, exposure to written communication on 60 km/h-zones (leaflet) and
  5. 5. Author's personal copy 210 C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 Table 1 Design of the first and second stage of the research Stage 1: 2 · 2 · 2 factorial design post-test only with four experimental conditions (C1–C4) Communication conditions Stage 2: group discussions with before–after measurements with two experimental conditions (CI–CII) No communication = Pre-test Anti-speeding C1 = tv-spot No spot Written communication 60 km zone Post-test N = 25 C2 N = 25 C3 N = 14 C4 N = 17 Anti-speeding tv-spot No tv-spot C1 Warming-up group discussion followed by second group discussion 3 groups Post-test CI = C2 3 groups N = 50 = C3 2 groups CII = C4 2 groups N = 30 (14 male) (15 male) (7 male) (10 male) exposure to an anti-speeding fear appeal (tv-spot) were independent variables, and the indicators of acceptability were dependent variables. In the second stage, the additional effect of social communication (group discussion) on attitude change was studied. Since each separate group discussion constituted a unique, non-standardised experimental environment for the participants, the results could not be studied with a standard factorial design and (M)ANOVA which require independence of observations. The second stage has a pre-test/post-test design, with two experimental conditions: written communication (CI) versus no communication (CII), whereas all participants were exposed to the fear appeal message. In order to combine research stages 1 and 2 it was convenient to use the post-test of stage 1 as the pre-test of stage 2 (see Table 1). This caused a slight flaw in the second stage design, with about 50% of the total sample having seen the fear arousing spot after the pre-test of stage 2, while the other half had seen it before the pre-test of stage 2. As these participants were evenly spread over the ‘‘Written communication’’ and ‘‘No communication’’ conditions, with an equal proportion of male and female subjects (see again Table 1), this imperfection is likely to have resulted in random error rather than in systematic bias. 2.3. Contents of communication The neutrally written information was a 4-page leaflet on 60 km/h-zones and informed participants of the introduction of a new 60 km/h-zone, providing information on the national road safety targets, the advantages of 60 km/h-zones in terms of improved road safety and the quality of life. The general slogan of the leaflet is: With 60.. you will live to be 80! The television spot5 showed a pedestrian who absentmindedly crosses a 60 km/h street and then unexpectedly is being hit by a car with the pedestrian’s body being propelled in the air. In the next instance, a trauma surgeon in an operating theatre explains about the damage to the human body. (His words: ‘‘The bumper hits the knee joint, tearing flesh and ligaments, the full weight of the skull smashes through the wind screen, the neck snaps, the skull shatters, and the pedestrian’s brain is turned into pulp. In little more than a second, the pedestrian’s body will hit the road, with a 70% chance of being dead’’). The surgeon then explains that the actual driving speed before the crash was 70 km/h resulting in a 15 m braking distance and that driving with 60 km/h limit would likely have prevented the crash (‘‘Had you been braking from sixty k’s not seventy there is a good chance you could have stopped in time and the pedestrian would have suffered nothing worse than a severe fright. Think about it!’’). 5 The television spot was devised by Gray Advertising, Victoria, in November 1999.
  6. 6. Author's personal copy C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 211 2.4. Questionnaires At the start of the procedure, participants received a questionnaire containing questions on: (1) knowledge about 60 km/h-zones; (2) the clarity and persuasiveness of leaflet and tv-spot; (3) problem perception with regard to speeding inside and outside urban areas; (4) intentions to speed in 60 km/h-zones; (5) attitudes towards introduction of 60 km/h-zones; (6) self-reported speeding on motorways, main roads, rural roads and roads inside urban areas; (7) general characteristics such as gender, age and education. Preceding the group discussions participants had to answer questions about 1–5 and following the group discussions the questions about 5–7 after the group discussion on the introduction of 60 km/h-zones. The questions in category 5 were therefore administered twice. The wording and answer scales of the main variables are shown in Tables 2–7. 2.5. Procedure Participants were randomly allocated to separate groups of 6–8 persons, after which the groups were randomly assigned to one of the four experimental conditions. The participants in the ‘‘Written communication’’ condition (C1 + C2) received a written leaflet on 60 km/h-zones seven days before the experiment. In the accompanying letter, participants were asked to read the leaflet before the experiment. Participants in the ‘‘No communication’’ condition (C3 + C4) received no leaflet or accompanying letter.6 After the first welcome and explanation, the participants in the ‘‘Fear appeal’’-condition (C1 + C3) were shown the fear appeal tv-spot, after which they completed the first part of the questionnaire (questionnaires 1–5). The participants in the ‘‘No fear appeal’’-condition (C2 + C4), were shown the tv-spot after completion of this questionnaire. In the second stage, initiated by the discussion leader, groups discussed safety issues in two rounds of discussion of about 30 min each. In order to acclimatize the participants to the changed experimental setting, the first round on publicity campaigns in general, served as a ‘‘warming up’’. The second round focussed on the effectiveness, justness and acceptability of 60 km/h zones, during which the discussion leader asked the group to comment on the plan to implement 60 km/h zones on a large-scale. After this discussion the participants completed the last part of the questionnaire (questionnaires 5–7). The discussion leader had to ensure that all persons participated in the discussion and to determine whether group members mutually agreed or diverged on certain topics. The discussion leaders were instructed to show neutrality on the topic. 2.6. Analyses The first stage results (a 2 · 2 · 2 factorial design) were analysed by three MANOVAs to test the effects of gender and the two types of communication on attitudes towards 60 km/h zones, intentions to comply with the 60 km/h speed limit and problem perception about to speeding. In each MANOVA the between-subjects factors were gender, exposure to written communication on 60 km/h-zone, and exposure to anti-speeding fear appeal, with two levels each. Effects that were not significant but could be indicative of a tendency in the results (p < .10) are also included in the results tables. In the tables both multivariate and univariate results are presented. The second stage results were analysed by comparing the before and after scores in the two information conditions (CI – leaflet versus CII – no leaflet) on six attitude-items using Wilcoxon signed rank tests. This is a conservative, non-parametric test that does not make assumptions about the distribution of the data. Separate Wilcoxon signed rank tests were used for male and female subjects in the ‘‘60 km/h communication’’ -condition, and in the ‘‘No communication’’-condition. 6 Due to administrative error, nine participants who were originally assigned to the ‘‘Non-exposure’’ condition, nonetheless received the leaflet for the ‘‘Exposure’’ condition, causing a disproportionate number of participants in the ‘‘Exposure’’ condition. Despite this deviation from the procedure of randomisation, the selection due to error was random and we believe that the assumption of random assignment can still be upheld.
  7. 7. Author's personal copy 212 C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 Table 2 Overview of results MANOVAs on attitude, problem perception, and intention to comply with the 60 km/h limit items Effect Dependent variables Attitudes 60 km/h zones G Problem perception Intention Ns k(2, 71) = 0.84; p = 0.002; g2 = 0.16 Univariate Speeding outside urban areas: F(1, 72)=10.5; p = 0.002, g2 = 0.128 Speeding inside urban areas: k(3, 70) = 2.3; p = 0.084; g2 = 0.090 Univariate Intent to speed when in a hurry and no speed checks: F(1, 72) = 4.5, p = 0.038, g2 = 0.058 Intent to speed when complying with limit takes 10 min longer: F(1, 72) = 4.3, p = 0.041, g2 = 0.057 F(1, 72) = 8.7; p = 0.004, g2 = 0.107 Intent to speed when others are speeding: F(1, 72) = 4.9, p = 0.029, g2 = 0.064 Univariate Pleasant: F(1, 66) = 3.7, p = 0.057, g2 = 0.054 Effective: F(1, 66) = 3.3, p = 0.074, g2 = 0.048 Wise: F(1, 66) = 5.0, p = 0.028, g2 = 0.071 Social: F(1, 66) = 3.6, p = 0.060, g2 = 0.052 Just F(1, 66) = 3.0, p = 0.087, g2 = 0.044 Necessary: F(1, 66) = 6.4, p = 0.014, g2 = 0.088 C F No significant effects multivariate or univariate effects Ns k(2, 71) = 0.88; p = 0.009; g2 = 0.12 Ns Univariate: Speeding inside urban areas: F(1, 72) = 7.0; p = 0.010, g2 = 0.088 Speeding outside urban areas: F(1, 72) = 7.8; p = 0.007, g2 = 0.098 Ns Ns G·C Ns Univariate (Table 4) Effective: F(1, 66) = 4.4, p = 0.039, g2 = 0.063 Pleasant: F(1, 66) = 3.3, p = 0.073, g2 = 0.048 Ns Ns Ns Ns G·F k(6, 61) = 2.20; p = 0.054; g2 = 0.1k (Table 5) Ns (Table 5) k(2, 71) = 2.8; p = 0.070; g2 = 0.072 Univariate: (Table 6) Speeding inside urban areas: F(1, 72) = 3.9; p = 0.053, g2 = 0.072 speeding outside urban areas: F(1, 72) = 4.2; p = 0.043, g2 = 0.056 (Table 6) Ns k(6, 61) = 1.9; p = 0.089; g2 = 0.16 Univariate (Table 8) Effective: F(1, 66) = 5.6, p = 0.020, g2 = 0.079 Ns Ns Ns Ns Ns Ns Ns Ns k(3, 70) = 0.88; p = 0.028; g2 = 0.12 (Table 7) Intent speed when others faster: F(1, 72) = 7.4, p = 0.008, g2 = 0.093 (Table 7) F·C G·F·C Ns Multivariate and univariate effects of gender (G), exposure to written 60 km/h communication (C) and exposure to anti-speeding fear appeal (F) and interactions between gender and written communication (G · C), fear appeal and written communication (F · C), and gender and fear appeal (G · F), and between all three variables (S · C · F).
  8. 8. Author's personal copy C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 213 3. Results 3.1. Perceptions of materials The subjects who had read the written communication about 60 kph zones (N = 50) rated this material on three 7-point evaluative scales: boring–interesting, unconvincing–convincing and unclear–clear. The leaflet was evaluated by most subjects as clear (M = 5.8 on 7-point scale), to some lesser extent also as interesting (M = 5.2) and near to scale midpoint concerning convincingness (M = 4.2). The subjects who had seen the television spot (N = 39) rated this spot on four 7-point evaluative scales: unclear–clear, unconvincing–convincing, not shocking–shocking, exaggerated–not exaggerated. Most subjects considered the television spot to be clear (M = 6.6 on 7-point scale), convincing (M = 6.0) and shocking (M = 6.0). Scores were somewhat more to the midpoint of the scale, though still on the positive side regarding the extent to which the television spot was not exaggerated (M = 5.3). 3.2. Overview of main effects of different messages on acceptability (stage 1) Table 2 provides an overview of results of MANOVAs and ANOVAs to test the effects of communication and gender on acceptability of 60 km/h zones. Although all 81 subjects participated in the entire experiment, there were some incomplete responses to some questions in the questionnaire, and consequently, degrees of freedom in Table 2 and cell means in Tables 4–9 do not always match the total of 81 subjects. In subsequent Sections 3.2.1, 3.2.2 and 3.3, the results in Table 2 are described. 3.2.1. Main effects of gender To test whether male and female drivers evaluated the communication messages differently, ANOVAs were performed with gender as independent variable and 7-point evaluative scales (described in Section 3.1) as dependent variables. Female participants assessed the written communication to be more convincing than male participants (F(1, 35) = 4.7; p = .038). Females perceived the fear appeal spot as more shocking than males (F(1, 36) = 11.1; p = .002) and also evaluated the tv-spot as more convincing (F(1, 35) = 7.8; p = .058) than males. In comparison to males, females reported to speed less frequently on main roads (F(1, 78) = 6.3; p = .014; 2 g = .07) and on roads in urban areas (F(1, 78) = 6.4; p = .013; g2 = .08). In addition to a non-significant tendency for females to report less frequent speeding on motorways (F(1, 78) = 2.8; p = .095), females also rated the introduction of 60 km/h zones as wiser and more necessary than did males (F(1, 66) = 5.0, p = .028, g2 = .071; F(1, 66) = 6.4, p = .014, g2 = .088). Furthermore, females judged speeding inside and outside urban areas as more dangerous than males (F(1, 72) = 8.7; p = .004, g2 = .107; F(1, 72) = 10.5; p = .002, g2 = .128), and reported stronger intentions to comply with the 60 km/h speed limit on all three intention-statements (F(1, 72) = 4.5, p = 0.038, g2 = .058; F(1, 72) = 4.3, p = .041, g2 = .057; F(1, 72) = 4.9, p = .029, g2 = .064). To explore whether problem perception of speeding was related to self-reported speeding we studied correlations between these questions (see Table 3). Table 3 Pearson correlations between problem perception of speeding inside and outside urban areas and self-reported speeding, for males and females (positive correlation indicating that high problem perception tends to be associated with low frequency of speeding) Self-reported speeding Females (N = 36) Males (N = 44) Problem perception speeding inside urban areas Problem perception speeding outside urban areas Problem perception speeding inside urban areas Problem perception speeding outside urban areas In urban areas On main roads between cities On motorways 0.293; p = 0.056 0.157; p = 0.315 0.263; p = 0.089 0.216; p = 0.165 0.350; p = 0.036 0.403; p = 0.015 0.359; p = 0.032 0.407; p = 0.014 0.068; p = 0.667 0.218; p = 0.161 0.288; p = 0.089 0.447; p = 0.006
  9. 9. Author's personal copy 214 C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 As can be seen in Table 3, for males, a higher problem perception regarding speeding inside urban areas was positively correlated with less self-reported speeding on roads inside urban areas (Pearson correlation = .36, p = .032), on motorways (Pearson correlation = .45, p = .006) and on main roads between cities (Pearson correlation = .41, p = .014). Also, for males higher problem perception regarding speeding outside urban areas was positively correlated with less self-reported speeding on main roads between cities (Pearson correlation = .40, p = .015) and roads inside urban areas (Pearson correlation = .35, p = .036). In contrast, for males none of these correlations were significant. 3.2.2. Main effects of type of communication A check on the written communication manipulation indicated that, as expected, participants in the ‘‘Written communication’’-condition had a significantly higher knowledge score (M = 3.7) than participants in the ‘‘No communication’’-condition (M = 2.5) (F(1, 77) = 52.1; p = .00, g2 = .40). The effect size measure corresponding to this effect, the partial eta squared (g2), is .40. Cohen (1988) characterizes g2 = .01 as small, g2 = .06 as medium, and g2 = .14 as a large effect size. As indicated in Table 2, there were no multivariate or univariate significant main effects of exposure to written communication on attitude, problem perception or on the intentions to comply with the speed limit. No hypothesis was formulated concerning the direction of the effects of the fear appeal spot. The fear appeal factor had no main effects on attitudes or intentions. The main effect of the anti-speeding fear appeal on problem perception was significant at the multivariate level (Wilks’ k(2, 71) = .88; p = .009; partial g2 = .12) as well as at the univariate level (F(1, 72) = 7.0; p = .010, g2 = 0.088; F(1, 72) = 7.8; p = .007, g2 = .098). Participants in the ‘‘Fear appeal’’-condition reported a lower problem perception of other drivers’ speeding inside and outside urban areas (M = 4.1, respectively M = 3.6) than participants in the ‘‘No fear appeal’’-condition (M = 4.6; M = 4.3). 3.3. Interaction effects 3.3.1. Interactions between gender and type of communication on acceptability The interactions between gender and communication are relevant for the hypothesis that persuasive effects would be less evident for males than for females (Hypothesis 2). With respect to the interaction between gender and written communication no significant results were found for problem perception or intentions. With respect to attitudes, the interaction was significant for the effectiveness-item (F(1, 66) = 4.4, p = .039, g2 = .063) and suggested a tendency for the pleasantness-item (F(1, 66) = 3.3, p = .073, g2 = .048). The male and female respondents in the ‘‘Written communication’’ condition had near equal ratings of how effective and pleasant the introduction of 60 km/h-zone would be (Table 4). In the ‘‘No communication’’-condition, males rated 60 km/h zones as less pleasant and effective than females. A comparison between the two communication conditions indicates that, compared to an uninformed same-gender control group, informed males tended to rate 60 km/h zones as more pleasant and effective and informed females tended to rate 60 km/h zones as less pleasant and effective. No significant effects for the interaction between gender and fear appeal were found on intentions, and only a possible tendency of effect was found on attitudes and problem perception. The MANOVA on attitude-items indicated a nearly significant interaction between gender and fear appeal (k(6, 61) = 2.20; p = .054; g2 = .18). Table 4 Attitude ratings concerning 60 km/h zones (pleasant, effective), according to gender and exposure to 60 km/h communication No communication (N = 27) Written communication (N = 47) Male (N = 15) Female (N = 12) Attitude scale Mean SD Mean SD Not pleasant–pleasant Not effective–effective 3.1 3.4 1.9 1.6 4.8 4.7 2.1 1.9 Sign Female (N = 20) Mean 0.013 0.030 Male (N = 27) SD Mean SD 3.9 4.5 1.8 1.5 3.9 4.3 1.9 1.7 Sign = significance of one-sided t-test, for male–female differences within cell. On both scales scores range from 1 to 7 with higher score indicating more positive attitude. Sign 0.455 0.352
  10. 10. Author's personal copy C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 215 Since no particular univariate results were found for any particular attitude-item we inspected the pattern of cell means for all attitude-items. As can be seen in Table 5, male and female respondents in the ‘‘No fear appeal’’- condition did not differ much on five of the six attitude ratings, the exception being the ‘‘necessary’’ item. In the ‘‘Fear appeal’’-condition, there were significant gender differences on three items. In the ‘‘Fear appeal’’-condition, female respondents tended to rate 60 km/h zones more positively on all attitude-items, whereas male respondents tended to show lower ratings on half of the items (pleasurable, effective, wise) and higher ratings on other items (social, just, necessary). Thus, for females the anti-speeding fear appeal spot seemed to have worked in one overall positive direction whereas for males a more capricious pattern of change was found. Though not significant (Wilks’ k(2, 71) = 0.92; p = .070; g2 = .07), the effect of the interaction between gender and fear appeal clarifies the main effects reported in Section 3.2.2. As can be seen in Table 6, male and female respondents rated the problem perception with regard to speeding inside and outside urban areas about equally high in the ‘‘No fear appeal’’ condition. In the ‘‘Fear appeal’’ condition, males rated the danger caused by speeding inside and outside urban areas less high than females. Under the influence of an anti-speeding fear appeal, males in particular downsized the problem of speeding. This finding supports the hypothesis that anti-speeding persuasive effects of communication would meet with more resistance by males, and that (positive) persuasive effects would be less evident for males than for females. The last interaction between gender and communication relates to the effect of the three-way interaction between gender, written communication and fear appeal. This interaction was significant for intentions to comply with the 60 km/h limit (k(3, 70) = .88; p = .028; g2 = .12), but not for attitudes or problem perception. On the univariate level, the effect of the three-way interaction on one intention-statement is significant F(1, 72) = 7.4, p = .008, g2 = .093. As can be seen in Table 7, the intentions of male and female drivers to comply with the 60 km/h speed limit when others are violating it, were not significantly different in three of the four communication conditions with the exception of the ‘‘Fear appeal without written communication’’-condition. In this particular condition, males reported the weakest intention to comply with the limit and females the strongest. It can also be seen that for the two other intention-items, this pattern of results is repeated, with the strongest gender difference arising in the condition of fear appeal without written communication, with Table 5 Attitude ratings concerning 60 km/h zones, according to gender and exposure to fear appeal No fear appeal (N = 39) Male (N = 23) Fear appeal (N = 35) Female (N = 16) Attitude scale Mean SD Mean 3.8 4.3 4.7 4.2 4.4 3.8 2.0 1.8 1.7 1.6 1.4 1.8 3.7 4.2 5.0 4.9 4.8 5.1 Mean SD Mean SD 0.443 0.492 0.272 0.069 0.169 0.017 2.1 1.6 1.3 1.2 1.4 1.7 Male (N = 19) 3.4 3.9 4.3 4.9 4.8 4.7 1.6 1.4 1.4 1.3 1.4 1.7 4.9 4.6 5.5 5.3 5.4 5.6 1.8 1.9 1.3 1.4 1.3 1.4 SD Not pleasant–pleasant Not effective–effective Stupid–wise Asocial–social Unjust–just Unnecessary–necessary Sign Female (N = 16) Sign 0.005 0.094 0.008 0.215 0.081 0.048 Sign = significance of one-sided t-test, for male–female differences within cell. On both scales scores range from 1 to 7 with higher score indicating more positive attitude. Table 6 Problem perception concerning speeding, according to gender and fear appeal conditions Item Fear appeal Male (N = 44) Female (N = 36) N Mean SD N Mean Sign SD I consider it dangerous when others speed within urban areas Yes No 20 24 3.7 4.5 1.3 0.9 19 17 1.6 4.7 0.6 0.5 0.007 0.193 I consider it dangerous when others speed outside urban areas Yes No 20 24 3.1 4.2 1.3 1.1 19 17 4.2 4.5 1.2 0.5 0.000 0.154 Sign = significance of one-sided t-test, for male–female differences within cell. The higher the score on the 5-point scale, the more agreement with perception of danger.
  11. 11. Author's personal copy 216 C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 Table 7 Intentions to violate 60 km/h-limit, according to gender, exposure to fear appeal and to written communication Item No fear appeal (N = 41) Fear appeal (N = 39) Male (N = 24) Female (N = 17) Mean SD Mean Sign SD Male (N = 20) Female (N = 19) Mean SD Mean Sign SD No communication Q1 Q2 Q3 2.7 2.8 2.8 1.3 1.4 1.4 2.0 2.4 3.1 1.0 0.8 0.7 0.143 0.282 0.269 3.0 2.7 3.3 1.4 1.1 .7 1.7 1.6 1.6 0.7 0.8 0.8 0.027 0.031 0.023 Written communication Q1 Q2 Q3 2.3 2.3 2.8 1.0 1.0 1.0 2.7 2.2 2.2 0.9 0.9 1.1 0.139 0.432 0.090 2.9 2.5 2.4 0.8 0.9 1.0 2.4 2.2 2.2 1.1 0.7 1.0 0.093 0.185 0.365 Sign = significance of one-sided t-test, for male–female differences within cell. (Q1) When you drive your car into a 60 km/h-h zone and you are in a hurry, will you comply with the speed limit if you know that your speed will not be checked? (Q2) When you drive your car into a 60 km/h-zone and you are in a hurry, will you comply with the speed limit if you know that a drive of about 30 min will take you 10 min longer? (Q3) When you drive your car into a 60 km/h-zone and you are in a hurry, will you comply with the speed limit if you notice that other drivers are violating the limit. The higher the score on the 5-point scale, the lesser the intention to comply with the speed limit. males reporting less intentions to comply and females stronger intentions to comply. This finding can be seen as (partial) support for Hypothesis 2 that persuasive effects would be less evident for males. 3.3.2. Interactions between types of communication This study formulated no hypothesis as to how a possible interaction between both types of communication would have an effect on each of the three acceptability indicators. The effect of the two-way interaction between exposure to written communication and exposure to anti-speeding fear indicated a possible tendency (with large effect size) on the multivariate level (k(6, 61) = 1.9; p = .089; g2 = .16) and a significant effect for the effectiveness rating at the univariate level (F(1, 66) = 5.6, p = .020, g2 = .079). Table 8 presents cell means for the effectiveness rating, for the conditions of communication separately. Table 8 indicates that 60 km/zones were rated as least effective in the ‘‘No communication – No fear appeal’’-condition, and as most effective in either the ‘‘Written communication – No fear appeal’’-condition or the ‘‘No communication-Fear appeal’’-condition. Another way to phrase it is that each type of communication achieved a more positive effect on attitude when it was not combined with the other type. Apparently, the two strategies of communication did not strengthen or reinforce each other. The three-way interaction between gender, exposure to written communication and exposure to fear appeal indicates one possible way that the different types of communication may have interacted. It seems that, at least for males, the negative effects of anti-speeding fear appeals were foremost present when they had not received written communication about 60 km/h zones. 3.4. Change in attitudes following group discussion (stage 2) For males and females in either the ‘‘Written communication (CI)’’ or ‘‘No communication (CII)’’ condition, non-parametric Wilcoxon signed rank tests were used to test before–after changes in attitudes towards 60 km/h zones (Table 9). Table 8 Attitude ratings of effectiveness of 60 km/h zones, according to the four conditions of exposure to persuasive communication (higher scores indicating more effective) Written communication (N = 47) Mean Fear appeal (N = 35) No fear appeal (N = 39) No communication (N = 27) SD Mean SD 4.1 4.7 1.7 1.4 4.6 3.5 1.7 1.9
  12. 12. Author's personal copy C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 217 Table 9 Changes in attitudes towards introduction of 60 km/h zones after group discussion, according to gender and exposure to written communication (higher scores indicating more positive attitude rating) Exposure to written communication Scale Female (N = 36) Male (N = 44) Mean before Mean after Sign Before After Sign Written communication Yes (N = 50) Not pleasant–pleasant Not effective–effective Stupid–smart Not social–social Unjust–just Unnecessary–necessary 3.9 4.3 5.3 5.1 5.1 5.3 3.8 4.8 5.4 5.2 5.0 5.4 0.659 0.136 1.0 0.855 0.435 0.662 3.9 4.5 4.7 4.8 4.7 4.5 3.2 3.5 3.7 4.5 4.5 4.2 0.037 0.006 0.051 0.194 0.499 0.326 No communication (N = 30) Not pleasant–pleasant Not effective–effective Stupid–smart Not social–social Unjust–just Unnecessary–necessary 4.8 4.7 5.2 5.1 5.1 5.4 3.0 3.3 4.0 4.6 4.3 3.4 0.031 0.057 0.019 0.129 0.072 0.005 3.1 3.4 4.3 4.1 4.4 3.7 2.3 3.5 3.7 3.7 4.0 3.9 0.223 0.888 0.147 0.204 0.047 0.872 Sign = Significance Wilcoxon signed rank test. As can be seen in Table 9, the majority of changes (significant and non-significant) on attitude-items was in a negative direction. The pattern of changes differed between males and females. Female participants in the ‘‘Written communication’’-condition showed no significant change following group discussion on any of the attitude-items whereas female participants in the ‘‘No communication’’ condition showed significant or nearly significant negative changes on 5 of the 6 items. Clearly, for female participants the tendency of social communication leading to negative changes in attitudes towards 60 km/h zones, was effectively counteracted by exposure to the 60 km/h-zone communication. Male participants changed in a negative direction on 3 out of 6 attitude-items in the ‘‘Written communication’’-condition and on only 1 item in the ‘‘No communication’’-condition, indicating that the information was not effective or even counterproductive. 4. Discussion The present study investigated the effects of different types of persuasive communication on the acceptability of speed reducing measures, and the additional effects of groups discussions. The following study limitations need to be taken into account when considering the main findings. Use was made of existing communication materials rather than specially developed materials or formats according to theoretical guidelines. It is not clear whether the results obtained with the present communication types would have been obtained with other, possibly better crafted materials. The leaflet was perceived by most respondents to be clear, but it scored less good in terms of convincingness. The spot was perceived by most subjects to be clear, convincing, and shocking indicating that it may have two important components of a fear appeal, some level of fear, and at least some minimum level of message efficacy. However, we did not measure separately the response efficacy (does message provide effective coping strategy?) and self-efficacy (can viewer perform coping strategy?) of the message which are thought to be in understanding the effectiveness of a fear appeal (Tay & Watson, 2002). A second limitation concerns the generalizability of results. In the present sample, car drivers of middle age and higher levels of education were over-represented and all drivers were residents of suburban areas. It is not certain whether a sample of younger or less educated drivers, or drivers in rural areas, would have yielded similar results. In summary, the first stage of the research found mixed support for both hypotheses, resulting from the different reactions of males and females to the types of persuasive messages. The first hypothesis that written communication would have a positive effect on attitudes but not on intentions, was only supported by the results for the male respondents (who reported more positive attitudes towards 60 km/h zones when they had read the written communication, but did not indicate stronger intentions to comply with the 60 km/h
  13. 13. Author's personal copy 218 C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 limit). For females, written communication produced less positive attitudes, but did not influence intentions to comply with the 60 km/h limit. Since written communication did not influence problem perception at all and only produced more positive attitudes for males but not for females, the results concerning this type of communication did not support the second hypothesis that persuasive effects would be less evident for males than for females. In contrast to the results for written communication, the results concerning the fear appeal were consistently in line with the second hypothesis. On all three acceptability indicators, the anti-speeding fear appeal had positive or neutral effects for females but only negative effects for males. In a nutshell, the fear appeal seemed to polarize male and female reactions to the introduction of 60 km/h zones. Let us recall the findings that support this. Firstly, concerning problem perception, males and females who had not seen the anti-speeding fear appeal spot, did not differ. However, when males and females had seen the spot, males had a significantly lower problem perception than females. Secondly, the anti-speeding fear appeal showed a less positive effect on the attitudes of males, with positive change on some of the attitude-items but not others, whereas the effect on attitudes was consistently positive for females. Finally, as revealed by the complex interaction between gender, fear appeal and written communication, females tended to report the strongest intentions to comply with the speed limit when they had seen the fear appeal without having had any prior communication, but males tended to report the weakest intentions. A final result of the first research stage concerned the possible interaction between the two types of persuasive communication. Although both types of communication dealt with the safety effects of speeding (in particular violating a 60 km/h limit), the diverging types of communication did not reinforce one another but rather tended to counteract or oppose each other. The positive effects on attitudes of each type of persuasive communication were largest when used in isolation. For males the negative effects of anti-speeding fear appeals on attitudes and intentions were primarily present when they had not received a written communication about 60 km/ h zones. Apparently, for males neutrally toned, argument-based communication counteracted negative, unwanted effects from a fear appeal approach that tended to evoke negative reactions. In the second stage of the present research, social communication took place in discussion groups on the advisability of 60 km/h zones. This provided us with the opportunity to study additional effects of group discussion over and above the other communication. This part of the research showed two main findings. First, attitudes towards 60 km/h zones tended to become more negative after group discussion. Second, for females, the neutrally toned, informative written communication countered this effect. Although written communication had no significant main effects on any of the three acceptability indicators and no effects at all on problem perception of speeding, it seems to have counteracted the negative attitude shift arising from group discussions for females, as well as reduced the counterproductive influence of the fear appeal for males. What are the possible implications of the present research for planning and designing road safety communications and for future research in this area? The research certainly calls into question the effectiveness of very confronting fear appeals in the anti-speeding area. Other research on road safety campaigns has indicated that fear appeals may fail to reach and influence the most relevant target audience for which they were explicitly developed (e.g. Tay & Ozanne, 2002). The present research points out that males and females may differ in the way they react to anti-speeding fear appeal type approaches. In the present study, the use of an anti-speeding fear appeal influenced female drivers in a positive direction but male drivers in a negative direction, contrary to the desired effects of persuasion, resulting in less positive attitudes regarding 60 km/h zones, lesser problem perception of speeding and weaker intentions to comply with the 60 km/h speed limit. One other recent study has pointed out similar gender effects with respect to reactions to road advertisements using fear appeals (or physical threats). Lewis, Watson, and Tay (2007) found that road safety messages about speeding and drink driving were regarded less relevant and influential by males than females. In the same study, males reported significantly less desirable speeding and drink driving intentions after viewing the road safety advertisement than females. Thus, it seems that gender is an important factor influencing the manner in which individuals process the relevance of an persuasive message using fear or threat. The counterproductive responses to anti-speeding fear appeal of male drivers in this research is a possible outcome of a social dilemma type situation where persons feel pressed to make a choice between personal preferences and social demands. One illustration of such a counterproductive response is provided by research by Steg (1996) that showed a decrease in problem perception after persons discussed the desirability of a
  14. 14. Author's personal copy C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 219 reduction of private car use in groups. In general, if persons are pressed to make a choice between own preferences and social demands, one possible outcome is that persons ‘‘retreat’’ from the direction of persuasion and show defensive, self-justificatory responses. In the present research, it might be argued that a defensive, self-justificatory response is apparent in the absent relationship between problem perception of speeding and self-reported speed behaviour for males. Whereas for females higher problem perception of speeding was associated with less self-reported speeding, for males no such relationship was found. One interpretation of this finding is that male drivers dissociate their own speeding behaviour from a social problem which can be interpreted as one type of self-justificatory response. In a social dilemma-like situation, safety campaigns that demand a drastic change in behaviour from drivers who feel personally confronted or even stigmatised by the message, can fail to produce expected results or even produce counterproductive results. This is especially the case when drivers notice that others are equally unwilling to conform to the norms or standards encouraged by the campaign. This particular dynamic may explain the negative attitude shifts arising from the group discussions. During the group discussions about the 60 km/h zones some persons indeed voiced personal doubts or criticisms about the desirability or effectiveness of 60 km/h zones. Other discussion participants who might have been less critical may have concluded that the general line of thought on the matter was rather negative and may have adjusted their attitudes towards the perceived group norm. There is no easy solution to the above mentioned negative dynamic. Campaign developers should consider to engage the relevant target group in a less confronting, choice-demanding way. In the specific area of antispeeding campaigns this could be done by asking for a small or specific contribution to a larger problem (e.g. speed reduction near schools, intersections, etc.) rather than a sudden large contribution (e.g. keeping the limit at all times and places, changing general driving style). One aim of road safety communication is to place collective problems on the public agenda and to raise public awareness. In our research, participants who had participated in group discussions and discussed advantages and disadvantages of 60 km/h zones tended to change their attitudes towards the introduction of these in a negative direction. The present research findings draw attention to the fact that as a result of social interaction, public awareness campaigns may (temporarily) lead to a decrease in the acceptance of a policy measure. As suggested before, a false-consensus effect may play a crucial role in this. The shift towards lower acceptability corresponds with observations in a field study. When the city council of Graz announced its intention to introduce a city-wide 30 km/h limit, the ensuing social communication about the future measure (which was not implemented yet) resulted in a reduction in acceptance from 64% (measured by a survey in 1989) to 44% (measured in August 1992) (Sammer, 1994). If social communication is likely to lead to criticism and a trend towards negative thinking about road safety measures, what can be done to reverse this trend? As shown, neutrally written communication could counteract negative attitude shifts arising from group discussions, at least among female divers. It is advisable to use fear appeals with great care as the possible defensive, self-justificatory responses resulting from this type of communication may fuel the negative opinions in the public debate. However, the highest impact is to be expected from the actual experiences with the measure. If these experiences are positive, the acceptability will increase, as was illustrated by the experience with introduction of 30 km/h zones in Graz. Despite the initial rejection, the actual implementation of these zones eventually led to a majority support. Consequently, in planning comprehensive programmes of traffic safety measures, authorities would do well to plan measures that will provide positive experiences (such as more driving comfort) in the beginning or in the middle of the programme. Finally, we conclude that fundamental and applied communication research can achieve a more realistic understanding of potential message or campaign effectiveness by studying the interaction between media exposure and social communication. Our findings suggest that persuasive impacts of messages can be assessed differently, dependent upon different target groups (in this research male versus female drivers) and upon the evaluation criterion (in the present context: first time exposure versus persistency of effect after group discussion). The method used in the present research – combining experimental design with group discussions and studying different types of measures – supplemented with more refined theoretical work on cognitive dissonance or self-justification processes (e.g. Holland, Meertens, & Van Vugt, 2002; Van Raaij, 2002) can provide a promising approach in this direction.
  15. 15. Author's personal copy 220 C. Goldenbeld et al. / Transportation Research Part F 11 (2008) 207–220 References Bamberg, S., & Rolle, D. (2002). Determinants of people’s acceptability of pricing measures: Replication and extension of a causal model. ¨ In B. Schlag & J. Schade (Eds.), Acceptability of transport pricing strategies (pp. 235–265). Amsterdam: Elsevier. Cauzard, J., & Quimby, A. (2000). Individual differences in attitudes to enforcement of traffic regulations. Working Paper 8 Workpackage 5. ESCAPE. Contract RO-98-RS.3047. Espoo: VTT. http://www.vtt.fi/rte/projects/escape/escape_wp8.pdf. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Erlbaum Associates. Das, E. H. H. J. (2001). How fear appeals work. Motivational biases in the processing of fear-arousing health communications. Utrecht: University of Utrecht. De Vries, N., Ruiter, R., & Leegwater, Y. (2002). Fear appeals in persuasive communication. In G. Bartels & W. Nelissen (Eds.), Marketing for sustainability. Towards transactional policy-making (pp. 96–104). Amsterdam: IOS Press. Feenstra, W., & Gotz, N. (2002). 30 km, ook voor ons! Evaluatie campagne 30 km gebieden van de gemeente Soest. TT-02-6. Veenendaal: ¨ Traffic Test. Fishbein, M., & Ajzen, I. (1975). Belief, attitude, intention and behavior: An introduction to theory and research. Reading, MA: AddisonWesly. Holland, R., Meertens, R., & Van Vugt, M. (2002). Self-justification among car drivers: Processes that undermine policy measures. In G. Bartels & W. Nelissen (Eds.), Marketing for sustainability. Towards transactional policy-making (pp. 334–342). Amsterdam: IOS Press. Ittner, H., Becker, R., & Kals, E. (2003). Willingness to support traffic policy measures: The role of justice. In J. Schade & B. Schlag (Eds.), Acceptability of transport pricing strategies (pp. 249–265). Amsterdam: Elsevier. Klandermans, B. (1992). Persuasive communication: Measures to overcome real-life social dilemmas. In W. B. G. Liebrand, D. M. Messick, & H. A. M. Wilke (Eds.), Social dilemmas: Theoretical issues and research findings (pp. 307–318). Oxford: Pergamon Press. Laapotti, S., Keskinen, E., & Rajalin, S. (2003). Comparison of young male and female drivers’ attitude and self-reported traffic behaviour in Finland in 1978 and 2001. Journal of Safety Research, 34, 579–587. Lewis, I., Watson, B., & Tay, R. (2007). Examining the effectiveness of physical threats in road safety advertising: The role of the thirdperson effect, gender, and age. Transportation Research Part F, 10, 48–60. Ruiter, R. A. C., Abraham, C., & Kok, G. (2001). Scary warnings and rational precautions: a review of the psychology of fear appeals. Psychology and Health, 16, 613–630. Sammer, G. (1994). General 30 kph speed limit in the city. The results of a model project in the city of Graz. In A. S. Hakkert (Ed.), Proceedings of the third international conference on safety and the environment in the 21st century: Lessons from the past, shaping the future, Tel Aviv, Israel, November 7–10, 1994 (pp. 598–608). Haifa: Technion Israel Institute of Technology, Transportation Research Institute. Social Issuers Research Centre (2004). Sex differences in driving and insurance risk. Oxford: SIRC. Stead, M., MacKintosh, A. M., Tagg, S., & Eadie, D. (2002). Changing speeding behaviour in Scotland: An evaluation of the ‘Foolsspeed’ campaign. Edinburgh: Scottish Executive Social Research. Steg, E. M. (1996). Behaviour change for reducing the use of motor-cars. Theoretical analysis and empirical study on problem awareness, willingness-to-change and evaluation of policy measures. Doctoral Thesis in Dutch, with extensive English summary. Groningen: Faculty of Psychological, Pedagogical, and Sociological Sciences, University of Groningen. Steg, L. (2003). Factors influencing the acceptability and effectiveness of transport pricing. In J. Schade & B. Schlag (Eds.), Acceptability of transport pricing strategies (pp. 187–202). Amsterdam: Elsevier. Suls, J., & Wheeler, L. (Eds.). (2000). Handbook of social comparison: Theory and research. New York: Kluwer Academic/Plenum Publishers. Tay, R., & Ozanne, L. (2002). Who are we scaring with high fear road safety campaigns? Asia Pacific Journal of Transport, 4, 1–12. Tay, R., & Watson, B. (2002). Changing drivers’ intentions and behaviours using fear-based driver fatigue advertisements. Health Marketing Quarterly, 19, 55–68. Van Raaij, W. F. (2002). Stages of behavioural change: Motivation, ability and opportunity. In G. Bartels & W. Nelissen (Eds.), Marketing for sustainability. Towards transactional policy-making (pp. 321–333). Amsterdam: IOS Press.