C Eyssartier
email: chloe.eyssartier@cerema.fr

L Chastenet
email: ludovic.chastenet@cerema.fr

M A Granie

Speed Reduction

H TO 80 KM/H ON FRENCH ROADS : ACCEPTABILITY OF THE MEASUREMENT

d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

BACKGROUND INFORMATION

In France, the decision was taken to reduce the maximum authorised speed from 90 to 80 km/h on two-way roads without a central separator from 1 July 2018. This decision was accompanied by the desire to draw up an objective evaluation after two years. This mission was entrusted to the Centre d'études et d'expertise sur les risques, l'environnement, la mobilité et l'aménagement (Cerema) by the Délégation à la Sécurité Routière in April 2018.

Cerema, in agreement with the Delegation for Road Safety, has defined an evaluation methodology that must take into account different constraints. The data used must be available "before" and "after" the implementation of the measure in order to be comparable. Where they are missing, an appropriate collection system should be defined, taking into account the size of the network concerned and the principles of proportionality and progressiveness, as prescribed in the 2014 Government Instruction.

The objective of this measure is to reduce the number of fatalities by reducing speeds on two-way roads without a central separator. The methodology defined is based on two main axes:

• an analysis of the evolution of the accidentality and the speeds practiced "before" and "after" the implementation of the measure; • a detailed analysis to understand the effects of the measure in terms of four themes: speed, accidentality, cultural change and societal effects. For further information on the general methodology of this evaluation, it is advisable to refer to the article by M. Millot et al. [START_REF] Millot | How to evaluate the reduction in speed from 90 km/h to 80 km/h on French roads[END_REF] while the societal impact of the measure is developed in the article by V. Buttignol et al. [START_REF] Buttignol | Réduction de vitesse de 90 à 80 km/h en France : quelle approche pour évaluer les effets socio-économiques[END_REF].

The purpose of this article is to present the first results concerning the acceptability of the measure two months before its implementation.

THEORETICAL ASPECTS

The credibility of speed limits remains one of the main reasons given by drivers for noncompliance with the speed limit [3;4]. "Credibility means that drivers consider speed limits to be sensible or appropriate to the characteristics and environment of the road" [START_REF] Goldenberg | The credibility of speed limits on 80 km/h rural roads:The effects of road and person(ality) characteristics[END_REF] This concept is consistent with the concepts of "realistic" [START_REF] Fildes | The speed review: road environment, behaviour, speed limits, enforcement and crashes[END_REF] or "acceptable" [START_REF] Risser | Acceptability of speeds and speed limits to drivers and pedestrians/cyclists[END_REF] speed limits.

The result of this concept is that if drivers consider a speed limit to be unreliable or inappropriate on a stretch of road, they will ignore the regulations and drive at the speed they consider most appropriate [START_REF] Gardner | Two views of motorist behavior in rura freeway construction and maintenance zones: the driver and state highway patrolman[END_REF]. If speed limits are generally not in line with the road infrastructure and environment, public policies to limit speed can be challenged by drivers.

In the light of these elements, studying the acceptability/acceptance of a measure to reduce speed limits makes sense.

Acceptance of a speed reduction measure

According to a Dutch study, on a road limited to 80 km/h [START_REF] Goldenberg | The credibility of speed limits on 80 km/h rural roads:The effects of road and person(ality) characteristics[END_REF], drivers report driving 8 km/h above the speed limit. Such exceeding of the speed limit is in line with other research showing that respondents tend to drive 10% above the speed limit, whether it is 60 km/h or 100 km/h [START_REF] Fleiter | The speed paradox: the misalignment between driver attitudes and speeding behaviour[END_REF].

Exceeding the speed limit by 10% is not considered a risk behaviour by many respondents. Thus, several studies show that as long as drivers feel comfortable and think they have control over their vehicle, they do not consider exceeding the speed limit to be dangerous or morally reprehensible [START_REF] Corbett | Explanations for understating in self-reported speeding behaviour[END_REF]. With regard precisely to the acceptability of reducing speed from 100km/h to 80km/ on dual carriageway roads, 78% of respondents surveyed in an Australian study would be in favour of such a reduction in authorised speed [START_REF] Mc Guffie | Community attitudes to speed limit[END_REF] 2.2. Acceptability of speed limits Driver characteristics have an impact on the acceptability of speed limits. Thus, respondents with a high score on the "sensation seeking" scale[12] are also those with a strong appetite for speed [START_REF] Sartre | European drivers and road risk. Part 2[END_REF]. The search for sensation, which is defined as in particular the tendency to take physical risks in order to feel intense emotions [12], is positively correlated with the number of offences sanctioned, the number of accidents and the number of kilometres driven annually [START_REF] Goldenberg | The credibility of speed limits on 80 km/h rural roads:The effects of road and person(ality) characteristics[END_REF]. Similarly, this intra-individual characteristic is related to the age of the respondents. For example, young drivers tend to be more interested in thrills at the wheel [START_REF] Delhomme | Personality predictors of speeding in young drivers : anger vs sensation seeking[END_REF]. Regarding the gender of respondents, the results are mixed although the vast majority of research shows that men report driving faster than women [15;16].

Standards (especially descriptive standards) also seem to play a role in the speeds used, more specifically the speeds used by other drivers. Thus, a driver who thinks that the drivers he observes on the road do not respect the speed limit will be more likely not to respect such a speed limit himself [START_REF] Haglund | Speed choice in relation to speed limit and influences from other drivers[END_REF]. Similarly, Swedish drivers say that it is more important to drive like others than to respect the speed limit [START_REF] Åberg | Observed vehicle speed and drivers' perceived speed of others[END_REF]. The reasons given for not respecting the speed limit are an underestimation of the danger of speed as mentioned above.

However, other motivations are put forward such as saving time and therefore arriving earlier at the destination (for 32% of drivers [START_REF] Rowland | Travel time savings and speed: actual and perceived[END_REF]) or in any case not arriving late (57% of research respondents [START_REF]Driver attitudes to speeding and speed management : a quantitative and quaitative stydy[END_REF]). Thus, drivers will underestimate the time saved for a speed going from 50 km/h to 60 km/h but will overestimate this time saving for a speed going from 85 km/h to 110 km/h.

On the other hand, a positive impact in terms of reducing the number of accidents but also their severity seems to be a convincing argument [START_REF] Mc Guffie | Community attitudes to speed limit[END_REF].

One of the consequences of an increase in speed is an increase in fuel consumption. For example, for 86% of respondents in a Canadian study [START_REF]Driver attitudes to speeding and speed management : a quantitative and quaitative stydy[END_REF], driving at 110 km/h instead of 100 km/h leads to an increase in fuel consumption. In addition, more men than women report that increased fuel consumption is one of the disadvantages of driving fast (20% of men).

In terms of environmental impact, only 6% of respondents spontaneously state that speed can have an impact on the environment. When this information is brought to their attention, only 45% believe that speed can have an impact on the environment [START_REF]Driver attitudes to speeding and speed management : a quantitative and quaitative stydy[END_REF]. According to a literature review [START_REF] Elvik | A restatement of the case for speed limits[END_REF], if drivers believe that speed can generate noise pollution and have a negative impact on the environment, these elements have very little impact on their decision to drive at a higher or lower speed.

Leverages to improve compliance with speed limits

• Infrastructure As mentioned above [START_REF] Goldenberg | The credibility of speed limits on 80 km/h rural roads:The effects of road and person(ality) characteristics[END_REF], infrastructure, traffic and weather conditions undeniably influence the acceptability of a speed limit.

Different authors demonstrate differences between the acceptability of a speed limit and the characteristics of the road. Thus, the absence of bends [5;22], housing along the road, good visibility [5;22] and the absence of obstacles or vegetation on the right side of the road [START_REF] Goldenberg | The credibility of speed limits on 80 km/h rural roads:The effects of road and person(ality) characteristics[END_REF] contribute to high speed. However, other factors must also be taken into account, such as weather or traffic conditions [START_REF]National Survey of Speeding and Unsafe Driving: Attitudes and Behaviour 2002[END_REF].

• Repressive policies

One of the last elements in getting the driver to comply with speed limits is repressive policies [24;25]. Automated sanction control" has made it possible to encourage drivers to 4]

26th World Road Congress reduce their speed, particularly in France [START_REF] Carnis | The French Automated Speed Enforcement Programme: A Deterrent System at Work[END_REF]. A distinction is made between specific and general deterrence [START_REF] Cestac | Survey on the relationship to the rule among French motorists[END_REF]. The first concerns the effect of enforcement action on drivers who have already been sanctioned. The aim is therefore to prevent a recurrence of the offence. General deterrence aims to encourage drivers to comply with a majority of traffic regulations. It concerns all road users. However, "a specific effect can help to reinforce a general effect" [START_REF] Cestac | Survey on the relationship to the rule among French motorists[END_REF]. Thus, the increase in the severity of penalties, which initially concerns only infringing users, has a dissuasive effect on other road users, who will adopt behaviour that complies with the rules of the highway code. Cestac et al [START_REF] Cestac | Survey on the relationship to the rule among French motorists[END_REF] detail and explain the complementarity of these two processes.

• Communication

While repression seems to be one of the most effective levers, education, which includes training and communication campaigns, remains a lever not to be neglected. Moreover, modifying only road signs is not enough to modify the speeds used [START_REF] Parker | 92-084)[END_REF]. Such a measure must be accompanied by communication actions.

METHOD

Objective

As mentioned above, studying the acceptability of this measure will make it possible to understand the behaviours observed in terms of speed and accidentality. Various studies show an evolution of acceptability once respondents have had experience with measurement, in short once they have been confronted with it, hence the importance of studying measurement before (acceptability) and after (acceptance) its implementation.

Longitudinal monitoring seems all the more relevant to us because societal events can have an impact on the perception of a measure (for example, the increase in fuel prices, etc.).

The objective of this article is to present the results of the first wave of surveys conducted before the implementation of the measure. 1 to 2 waves of surveys are planned for the end of 2019.

Methodology

Different dimensions, based on the elements from the literature, will be studied in this study:

utility: the more useful a device is perceived as useful, i.e. as meeting a societal need, the more accepted it will be [START_REF] Nielsen | Heuristic evaluation[END_REF]. In road traffic rules, perceived utility is an important determinant of their acceptability. In short, does the public policy implemented meet a need? Returning to the acceptability of a reduction in speed, is there a problem of road safety related to speed for the French population?

Usability: this idea corresponds to the ease of use of a system, which will also determine the acceptance of the system by users. It is divided into several sub-dimensions: effectiveness, satisfaction and ease of application [START_REF] Nielsen | Heuristic evaluation[END_REF] Thus, a road safety rule will be all the more acceptable, as it is perceived by road users as effective (a 10 km/h reduction in the limit will reduce accidents), satisfactory (it does not create too much discomfort) and easy to apply ("reducing speed is not too difficult").

perceived equity: a measure will be all the more acceptable if it concerns all users. The importance of this factor is particularly relevant to the study of automatic control but is not studied by researchers interested in speed reduction.

the social environment: the acceptability of a rule can also be influenced by the individual's social environment [START_REF] Terrade | Social acceptability: the consideration of social determinants in the analysis of the acceptability of technological systems[END_REF]. As mentioned above, social norms play a role in the acceptability of public policy. The more the driver notices that other drivers comply with this new regulation (descriptive injunctive standard) and the more his relatives will encourage him to comply with it (injunctive standard) the more the driver will comply with this new regulation.

behaviour: the acceptability/acceptance or non-acceptability/acceptance of a public policy is reflected in behaviour, more precisely, in the achievement of consistent (users have complied) or inconsistent (users do not comply with the new limitation) behaviour with the new regulations but also in circumvention strategies (changing routes, using radar warning devices, changing travel modes by favouring carpooling or public transport, for example).

The various dimensions presented above, breaking down the notion of acceptability, were translated into a questionnaire that was distributed by a French polling firm to a representative sample of the French population. To this end, demographic issues (age, gender, etc.) have been introduced. Almost all questions are closed questions.

Population

The questionnaire was distributed between the end of April and May 2018, two months before the implementation of the measure, to 5,310 respondents aged 18 and over These respondents have the following characteristics:

• 52.9% female (N=2809) and 47.1% male (N=2,501)

• the average age is 47.13 years • concerning the mode of transport most used on a two-way road in the last 6 months:

• the car is still used by the majority of respondents: 83.7% or 4,446 people;

• public transport by 6.3% or 334 people;

• the bicycle by 7.1% or 380 people;

• two-wheelers powered by 2.5% or 138 people. • the respondents reside:

• 22.5% of them in a rural area (1193 people); • 18.1% of them in a city with a population of less than 20,000 (957 people); • 13.6% in a city with a population of between 20 and 100,000 (724 people); • 29.9% in a city with a population of more than 100,000 (1,590 people); • and 15.9% in the Paris conurbation (846 people).

RESULTS

General attitude

Respondents were on average against the measure: 40% were totally opposed to the measure and 30% were somewhat opposed.

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26th World Road Congress Averaging this variable is useful for us to establish the link between the general attitude of respondents and the variables studied presented in the following paragraphs. The average is 2.01 on a 4-point scale (standard deviation =1.01), ranging from 1, quite opposite to 4, quite favourable. In summary, consistent with the previous results, respondents were on average "somewhat opposed to the measure".

Gender

Women have a more favourable attitude to measurement than men. Their average attitude is 2.07 (N=2809) unlike men who have a more negative attitude with an average of 1.93 (N=2501)[F(1;5308)=24.35; p=0.000001].

Age

The results show that the older the individuals, the more favourable they are to the measure. The correlation between these 2 variables is positive and statistically significant (r²=0.04, p ≤.05).

Area of residence

The denser the areas of residence, the more favourable the respondents are to the measure.

Figure 1 shows that there is no difference to be observed between users residing in a municipality with a population of 20,000 to 100,000 and those residing in municipalities with a population of less than 20,000 and rural residents. On the other hand, the other categories differ from each other.

In summary, the denser the areas of residence, the more supportive respondents are of the measure. The results show that the more supportive respondents are of the measure, the more they consider that there is an increased risk of accidents if the speed limit is exceeded by 10 km/h (M=2.23) (r²=0.55, p<0.05).

Effectiveness of the measurement

The objective here is to determine whether there is a link between the effectiveness of the measure and the attitude towards the measure. To do this, respondents were asked to rank on a 4-point scale on each of the impact points (1, no, certainly not; 2, no, probably not, 3, yes, probably and 4, certainly).

First, the effectiveness of the measure has a strong impact on the acceptability of the measure since it explains 60% of the attitude towards the measure[R² ajut=0.60 F(16, 3950)=382.5; p<0.00000]. However, it should be noted that environmental arguments are among the least damaging (see Table 1).

Frequency of compliance

The scale was coded in 5 points (1 never; 5 systematically). The more respondents agree with the measure, the more they report that they intend to comply with the measure (M=2.92; r²=0.44 p≤0.05). 12.4% of respondents did not wish to answer this question (N=659) (see Table 2).

Table 2-Distribution of respondents according to their intention to comply with the measure

Reasons for the intention to comply with the measure

Respondents who answered "consistently" or "most often" were asked why they intend to comply with the measure. For this purpose, a list of items was proposed to them from which several could be selected.

The analysis below aims to compare the responses provided by respondents who plan to comply with the measure "most often" and "systematically".

Respondents intending to comply with the measure "most often" and "systematically" differ on the following items:

• "always respects the highway code": 51% "most often" (N=1098/2134) and 72% "systematically" (N=1038/1442) (Chi2=150 ; p=1.16 e-34)) • "pay attention to pedestrians": 22% "most often" (N=471/2134) and 24.8% "systematically" (N=359/1442) (Chi2=3.85; p=0.04) • "responsible for my passengers" 26.6% "most often" (N=569/2134) and 33.4% "systematically" (N=482/1442) (Chi2=18.96; p=1.33 e-5) • "does not like to drive fast" 12.8% "most often" (N=275/2134) and 18.5% "systematically" (N=267/1142) (Chi2=1.33 ; p=1.33 e-14)

On the other hand, with regard to fear of punishment, more users who plan to comply with the measure "most often" (N=1303/2134; 61%) reported having this type of practice than did "systematically" (N=548/1442; 38%) (Chi2=183,20; p=9,67 e-42).

With respect to the following items, there is no difference between users who report that they intend to comply with the measure "most often" and "systematically":

• "Fuel savings": 8.7% "most often" (N=187/2134) and 7.14% "systematically" (N=103/1442) (Chi2=3.03 ; p=0.082). • "4.1% "most often" (N=88/2134) and 5.2% "systematically" (N=75/1442) (Chi2=12.29; p=.13). • The "allows you to drive slower": 2% of respondents "most often" (N=44/2134, 2%) and 1.9% of respondents "systematically" (N=28/1442) (Chi2=0.07 ; p=0.08).

Reasons for the intention not to comply with the measure

Respondents who answered "sometimes", "rarely" or "never" were asked the reasons given for not complying with the measure. For this purpose, a list of items was proposed to them and they could select several of them.

The analysis below compares the responses provided by respondents intending to comply with the measure "sometimes", "rarely" and "never".

Users "rarely" differ on the following items from users "never":

• on "having little chance of being controlled": 3% of "never" (N=4/131) and 10.7% of "rarely" (N=37/344) (Chi2=7.14; p=0.007); "I am in a hurry": 8.4% of "never" (N=11/131), 14% of "rarely" (N=76/344) (Chi2=11.89 ; p=0.0005) • "no risk, I control my vehicle": 26% of "never" (N=50/131) vs 36.9% of "rarely" (N=127/344) (Chi2=13.54 ; p=0.00002)

Users "sometimes" differ from users "never" on the fact of liking to drive fast: 26% of "never" (N=20/131) and 8.6% of "sometimes" (N=8.6%) (Chi2=5.27; p=0.02) and users "rarely" on vehicle control no risk : 36.9% "rarely" (N=127/344) (Chi2=13.54; p=0.00002) and 30.3% "sometimes" (N=182/600) (Chi2=53.84; p=2.15e-13).

On the other hand, no difference appears on the other items:

• "the road allows me to go fast": 35.1% of "never" (N=46/131), 32.2% of "rarely" (N=111/344) and 35% of "sometimes" (N=210/600) • "I am caught in a stream of vehicles": 27.5% of"never" (N=36/131), 31.6% of"rarely" (N=109/344) and 30.6% of"sometimes" (N=184/600) • "while driving fast I am less embarrassed": 13.7% of "never" (N=18/131), 13.3% of "rarely" (N=46/344) and 10.1% of "sometimes" (N=61/600) 4.9. Equity: attitude towards young and heavy goods vehicle drivers Since the speed allowed by young and heavy goods vehicle (HGV) drivers was before the introduction of 80 km/h, the aim here was to ask respondents about the relevance of reducing the speed of these two categories of road users. In short, the authorized speed must be less than 80 km/h.

The results show that the more respondents support the measure, the more they would support a speed reduction for young drivers (r²=0.34 p ≤0.05) and also for heavy goods vehicles (r²=0.34 p ≤0.05).

4.10. Ease of use A measure will be all the more acceptable if it is considered easy to apply. To test this, we asked respondents to what extent compliance with this new regulation is perceived as easy for them but also for other drivers.

The results show that the more supportive users are of the measure, the easier they find it to apply themselves (t=41.37; p=0.00) (M=2.48) but also the easier it will be for others to comply (t=-10.177; p=0.00) (M=2.14).

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26th World Road Congress 4.11. Travel time As we have read in the press, a recurring argument concerns lost time. Respondents were asked to evaluate the impact of the measure on their travel time on their typical trip. 6 response modalities were proposed ranging from 1 -the travel time will be reduced -to 6the additional travel time will be more than 20 minutes.

The 4 categories of answers are different from each other. In summary, the more supportive respondents are of the measure, the less likely they are to think it will waste their time (see Table 3).

The "opposite" ("completely opposite" and "rather opposite") users consider that the measure will cause them to lose between less than 5 minutes and between 5 and 10 minutes. On the other hand, favourable users ("quite favourable" and"rather favourable") estimate that the time lost would, in the worst case scenario, be less than 5 minutes. Knowing that the average journey length is between 20 and 30 km, unfavourable users therefore estimate that the loss of time will be in the order of 10 to 15s of a kilometre. For favourable users, it will be less than 10s of a kilometre. In order to evaluate the strategies considered by respondents following the implementation of the measure, different strategies were proposed to respondents who could choose several.

Respondents who are "strongly opposed" to the measure are more likely to report that they do not intend to change their habits.

There are more respondents who are "somewhat opposed to the measure":

• to declare that they intend to use a speed limiter more than other respondents;

• not to change their habits. However, fewer of them have chosen this option than "completely opposed" users.

There are fewer of them in:

• declare carpooling;

• to use other modes of travel such as 2WD.

Respondents who were "somewhat in favour of the measure" were more likely to report:

• intend to use a speed limiter only by "completely opposed" and "rather opposed" users. However, they do not differ from "completely favourable" users;

• intend to use other modes of travel than the "completely opposite" and "rather opposite" users. However, they do not differ from "completely favourable" users; • intend to carpool and use a 2WD that "opposite" ("completely opposite" and "rather opposite") users but less than "completely favourable" users); • use other modes of travel such as public transit than the "opposite" ("completely opposite" and "rather opposite") respondents. The percentages are roughly equivalent between the "very positive" and "somewhat positive" respondents.

Fewer of them report:

• intend to use a speed limiter only by "completely opposed" and "rather opposed" users. However, they do not differ from "completely favourable" users; • not intend to change their habits than the "opposite" ("completely opposite" and "rather opposite") users but more than the "completely favourable" users; • to report using other modes of travel such as public transit than the "opposite"

("completely opposite" and "rather opposite") respondents. The percentages are roughly equivalent between the "very positive" and "somewhat positive" respondents.

Respondents who were "strongly in favour of the measure" were less likely to report that they intended to use a speed limiter or not change their habits.

More of them are reporting:

• intend to use other modes of travel, carpool or use a 2WD;

• use other modes of travel such as public transit than the "opposite" ("completely opposite" and "rather opposite") respondents. The percentages are roughly equivalent between the "very positive" and "somewhat positive" respondents.

DISCUSSION

CONCLUSION

According to the literature, for such a policy to be accepted, drivers must have been aware of a road safety problem (accidentality) resulting from a specific behaviour (speed). They must also consider that the public policy put in place is effective, fair and easy to apply and be prepared to comply with the standards and instructions set by that public policy [START_REF] Lahausse | Attitudes towards current and lowered speed limits in Ausralia[END_REF].

The majority of respondents are opposed to the measure, specifically 40% are "strongly opposed" while 30% are "somewhat opposed". According to the literature [15;16], these are mainly men and rather young. The most unfavourable respondents to the measure are also those who believe that a "low" exceeding the speed limit, i.e. 10km/h above the authorised speed, is not a risk factor. Such a result is consistent with those found in other countries but also in France [START_REF] Gaymard | The representation of driving among young drivers. A study of road conditionality[END_REF].

In any case, it is the effectiveness in terms of reducing accidentality but also the severity of accidents and speeds practised that influences the acceptability of the measure in accordance with the above-mentioned work [START_REF] Mc Guffie | Community attitudes to speed limit[END_REF]. On the other hand, and in line with Elvik's (2010) work, environmental factors in terms of reduced fuel consumption and pollutant emissions have no impact on acceptability.

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26th World Road Congress In terms of usability, i.e. the ease of complying with this new limitation, it should be noted that the more respondents are in favour of the measure, the easier they consider it to reduce their speed. However, this seems easier for them than for other drivers. We therefore find here a phenomenon known in social psychology as "the self-indulgence bias" [START_REF] Miller | Self-serving Biases in the Attribution of Causality[END_REF].

For those most in favour of the measure, this reduction in speed should also apply to young and HGV drivers, who will continue to drive at 80 km/h. On the other hand, the least favourable drivers believe that reducing the speed limit for these subcategories of road users is not desirable. This result is not surprising since they consider that a slight exceeding of the speed limit is not a risk factor. On the other hand, these respondents, i.e. the most hostile to the measure, tend to overestimate the time lost, which they estimate to be between 5 and 10 minutes for a journey of between 20 and 30 km. However, the results presented by V. Buttignol et al [START_REF] Buttignol | Réduction de vitesse de 90 à 80 km/h en France : quelle approche pour évaluer les effets socio-économiques[END_REF] suggest that the time lost, on a trip that includes a majority of two-way roads without a central separator, is in the order of one second per kilometre, or 20 to 30 seconds for a trip of 20 to 30 km.

While the vast majority of respondents say they do not agree with the measure, more than 70% of respondents say they intend to comply "most often" or "systematically" with the future speed limit. The reasons given mainly concern compliance with the highway code and fear of punishment. Fuel savings and pollution reduction are reasons given by less than 5% of respondents. Concerning the 10% of respondents who state that they intend to comply with the new limitation only "never" or even "rarely", the reasons given concern "the road" (the road allows me to go fast), the control of one's vehicle and the fact of being caught in a flow of vehicles. In short, based on previous studies, the reasons given for this sub-population of respondents relate to the impact of infrastructure, over-confidence in driving ability and the behaviour of other drivers (the descriptive standard).

While a large majority of respondents state that they intend to comply with the measure, the drivers who are least in favour of the measure are those who say they do not want to change their travel practice but are willing to use a speed limiter. The most favourable users, on the other hand, are considering other modes of travel.

ACTION TO BE TAKEN

Logically, we assume that the users most likely to change their attitude towards the measure more positively are the "rather opposite" users. According to some authors, drivers tend to oppose lowering the speed limit, although most of them gradually accept the new limit [START_REF] Lahausse | Attitudes towards current and lowered speed limits in Ausralia[END_REF]. The survey waves that will be conducted after the implementation of the measure will allow us to test this hypothesis.

In addition, the analyses to be carried out in the following waves will make it possible to provide information on the acceptance of the measure, its evolution and the cultural changes induced, but also to enrich the results from the other components of the evaluation, presented in the paper by M. Millot et al. [START_REF] Millot | How to evaluate the reduction in speed from 90 km/h to 80 km/h on French roads[END_REF], in order to assess this measure as comprehensively as possible.

In any case, it should be borne in mind that it seems difficult or even impossible to have a speed limit that is acceptable to all drivers in view of the large disparities in terms of acceptable speed for the same road situation. These distinctions are due to intra-individual differences (e.g. personality traits) [START_REF] Goldenberg | The credibility of speed limits on 80 km/h rural roads:The effects of road and person(ality) characteristics[END_REF].

Figure 1 -

 1 Figure 1 -Distribution of respondents by area of residence according to their adherence to the measure

Table 1 -Impacts of the measure as a function of membership (Review the format below to save space! Remove the chips)

 1

	Negative factors	Neutral" factors that do not appear in	Positive factors
		the analysis as statistically
			significant
	increase the risk of dangerous	reduce the risk of collision because	reduce the number of deaths
	exceedances (ß=-0.04 ; t=-4.73 ;	the stopping distance will be less	(ß=0.21; t=9.73; p=0.0000)
	p=0.0002)	(ß=0.0008; t=-0.05 ; p=0.95)	reduce the number of injuries
	increase the risk of being	reduce fuel consumption (ß=-	(ß=0.11 ; t=-5.37 ; p=0.000)
	sanctioned (ß=--0.09 ; t=-8.87 ;	0.0009 ; t=-0.06; p=0.94)	reduce the number of material
	p=0.000)	reduce pollutant emissions (ß=0.005 ;	accidents (ß=0.11 ; t=5.90 ;
		t=0.75 ; p=0.45)	p=0.000)
		facilitate traffic flow (ß=0.09 ;	reduce the severity of accidents (ß=
		t=0.38 ; p=0.69)	0.08 ; t=4.61 ; p=0.0004)
		reduce frontal shocks (ß=0.02 ;	reduce the risk of collision because
		t=1.61 ; p=0.10)	your field of vision will be smaller
		easily	inserted (ß=0.02 ; t=1.35 ;	(ß= 0.08 ; t=5.19 ; p=0.0000)
		p=0.17)		reduce the speeds practiced
				(ß=0.10 ; t=7.41;p=0.0000)
				reduce off-road vehicle trips (ß=
				0.05 ; t=3.26 ; p=0.001)
				facilitate intersection manoeuvres
				(ß= 0.03 ; t=2.18 ; p=0.03)
	4.8. Compliance with the measure

according to their adherence to the measure

		Quite the	Somewhat	Somewhat	Completely
		opposite	opposite	favourable	favourable
	Never ever	6,1 % (N=120) 0,4 % (N=5) 0,2 % (N=5)	0,9 % (N=4)	131 (2,8%)
	Rarely does it	15,6 %	0,2 % (N=28) 0,6 % (N=5)	0,5 % (N=2)	344 (7,4%)
	happen	(N=309)
	Sometimes	21,3 %	10,1 %	38 % (N=32)	1,8 % (N=8)	600
		(N=420)	(N=140)			(12,9%)
	Most of the time 39 % (N=770)	57,1 %	54,5 %	24,8 % (N=109)	2134
			(N=793)	(N=462)		(45,9%)
	Systematically 18 % (N=356)	30,5 %	40,9 %	72 % (N=316) 1442 (31%)
			(N=423)	(N=347)
		100 %	100 %	100 %	100 % (N=439)	4651
		(N=1975)	(N=1349)	(N=848)		(100%)
			8]		26th World Road Congress

Table 3 : Impact of the measure on travel times according to the degree of adherence to the measure on a scale from 1 (reduced travel time) to 6 (additional travel time greater than 20 minutes)

 3

		Quite the opposite Somewhat opposite	Somewhat	Completely
				favourable	favourable
	Travel time	3,64	3,35	2,82	2
	4.12. Adaptation strategies

26th World Road Congress


Clarisse Sieckenius De Souza
email: clarisse@inf.puc-rio.br

A contrastive study of pre-and post-legislation interaction design for communication and action about personal data protection in e-commerce websites

Keywords: General Data Protection Regulation (GDPR), Interaction Design, Semiotic Engineering

The European General Data Protection Regulation (GDPR) has had a major impact on data collection and processing practices. It has also challenged interaction design aiming to support the effectiveness of data owners' rights, their informed decisions, and their actions regarding how personal information is used by companies, governments, and others. Similar legislation has been issued in various non-European countries, which means that, in this respect, the HCI community has an important role to play for users all over the world. This paper presents the conclusions of a contrastive study with four major e-commerce websites in Portugal, where data protection law has been effective since 2018, and four analogs in Brazil, where the national Data Protection Law (DPL) has been sanctioned but will only be effective in 2020. The purpose of the study is to examine the pre-legislation to post-legislation evolution in the design of interaction for communication and action about personal data protection matters, so as to anticipate some of the threats and opportunities ahead of us. Using concepts and elements of Semiotic Engineering methods and techniques, we found that, within the scope of this study, GDPR seems to have had little impact on what European users can do and experience online, compared to pre-DPL Brazilian users. We discuss some of the possible reasons for this and conclude with thoughts on the role of interaction design in empowering data owners for this new regulation era.

Introduction

The European General Data Protection Regulation (GDPR) [START_REF]The European Parliament and Council General Data Protection Regulation[END_REF] has had a major impact on data collection and processing practices. It has also challenged the design of interaction aiming to support the effectiveness of data owners' rights, their informed decisions, and action regarding how personal information is used by companies, governments, and others. [START_REF] Hildebrandt | Slaves to Big Data. Or Are We? IDP[END_REF] Similar legislation has been issued in various non-European countries, such as Brazil [3], for example, where part of this research takes place. The HCI community has thus an important role to play in helping users from all over the world to access and exert their rights in this new era of data protection legislation.

E-businesses constitute an interesting domain to evaluate what interaction design currently allows users to do or not do with respect to personal data management. Years ago, when e-commerce started to flourish, one of the major technical challenges was to secure sensitive user data like name and identity, home address, and credit card numbers. Moreover, legislation protecting consumers, sellers, and service providers had to be enforced by online processes. These factors gave rise to important advancements in data security and privacy, as well as to legislation-compliant business process modeling and implementation techniques.

Personal data protection (PDP) legislation does involve security, privacy and legislation-compliant business processes, for which we have decades of successful research and development efforts. But it also involves new complex elements, such as informed consent and the interpretation or justification of algorithmic decision making, about which there is much less available knowledge to support urgently needed solutions.

This paper presents the conclusions of a contrastive study with four major e-commerce websites in Portugal and four analogs in Brazil. As a European country, Portugal must enforce GDPR requirements for all online businesses that collect and process their clients' data. Brazil, however, is at a different stage. The Brazilian Data Protection Law (DPL) has been issued in August 2018, and will become effective only in 2020. We are specifically interested in how interaction design may have changed (or needs to change) in order to ensure the users' ability to know and exert their rights online.

Portugal and Brazil are used in the study because both countries speak the same language and share much of their culture. The focus of the contrast is PDP-related interaction communication and action for first-time website visitors. These visitors are the ones who must take the most important step in personal data collection and processing matters, they must give the data collectors and processors their informed consent. As a requirement for such consent, they must be able to understand and anticipate their rights, what kinds of decisions they can make, and actions they can take regarding their data. Appropriately informed consent should allow users to infer (even if in very general terms) how to act and what kind of response to expect in key situations, such as when exercising the right to be forgotten, or to retrieve their personal data from one provider and transfer it to another.

We used concepts and elements of Semiotic Engineering [START_REF] De Souza | The semiotic engineering of human-computer interaction[END_REF] methods and techniques to capture the content and style of metacommunication in the selected websites. Metacommunication, as proposed by Semiotic Engineering, is an especially productive concept for this kind of analysis. Very briefly, according to this semiotic theory of HCI, user interfaces are communication proxies that speak for interaction designers in dialogs with users, which take place at interaction time. Through their structure and behavior, systems interfaces tell users about the modes, the means, the possibilities, and the effects of the kinds of communication that they may have with software systems and applications. By so doing, they also communicate one party's intent to the other. Hence, human-computer interaction, in Semiotic Engineering terms, is a case of social metacommunication between humans, expressing the designers' communication about how, when, where, why, and for what purposes users can, in turn, communicate back with the designed technology.

Compared to user-centered HCI alternatives [START_REF] Norman | User Centered System Design: New Perspectives on Human-Computer Interaction[END_REF][START_REF] Holtzblatt | Rapid contextual design: a how-to guide to key techniques for user-centered design[END_REF][START_REF] Ritter | User-centered systems design: a brief history[END_REF], for instance, the analysis of metacommunication has the advantage of bringing software designers and users together at interaction time [START_REF] De Souza | Semiotic engineering: bringing designers and users together at interaction time[END_REF], that is, of investigating how senders' and receivers' communicative goals are expressed and enabled, how different communicative strategies support interface-mediated meaning negotiations, how artificial interface languages and protocols occasionally create asymmetries of power, and so on, and so forth.

Our findings show that metacommunication design in this particular context is surprisingly poor, both in Portuguese and Brazilian websites. In other words, so far, GDPR seems to have had little impact on what users can do while interacting with the analyzed European websites, in comparison with the non-European, pre-legislation ones. Based on our findings, we argue that if nothing changes with respect to supporting interaction for personal data management and decision making, we may, against our will, end up contributing to the ineffectiveness of GDPR and similar legislation around the world. Hence the role of interaction designers in this context is critical, as Bus and Nguyen had already concluded following a different line of reasoning. [START_REF] Bus | Personal data management -a structured discussion[END_REF] This paper is organized in five sections, starting with the present introduction. Section 2 is a commentary on related work. Section 3 describes our contrastive study, with special attention to the theory and the methodology that was used. Section 4 presents our findings. Finally, Section 5 discusses our conclusions and contribution, the limitations of this study, and some directions for future research.

Related Work

Although GDPR is not just about privacy, this is a central notion in the European regulation. Privacy studies go a long way in HCI. [START_REF] Iachello | End-user Privacy in Human-computer Interaction[END_REF] Legally, however, the role of the user after GDPR has changed in important ways. For example, European users are now legally entitled to specific privacy management rights, like giving and revoking consent for the collection and processing of their data. To be sure, GDPR is, to a considerable extent, the result of cultural change regarding privacy and information abuse online. But it also raises new questions, like the users' right to monetize their personal data in profitable ways, and the consequences of controlling intelligent agents by learning how they predict user behavior, and then playing the reverse game to evade control. [START_REF] Hildebrandt | Slaves to Big Data. Or Are We? IDP[END_REF] Users have been long known to agree with terms of services (ToS) and privacy policies (PP), having little understanding (or no understanding at all) of what such terms and policies are saying. [START_REF] Obar | The biggest lie on the Internet: ignoring the privacy policies and terms of service policies of social networking services[END_REF][START_REF] Carolan | The continuing problems with online consent under the EU's emerging data protection principles[END_REF][START_REF] Nguyen | Does Privacy Information Influence Users' Online Purchasing Behavior[END_REF][START_REF] Acquisti | Privacy and human behavior in the age of information[END_REF][START_REF] Angulo | WTH..!?!" Experiences, Reactions, and Expectations Related to Online Privacy Panic Situations[END_REF][START_REF] Tsai | The Effect of Online Privacy Information on Purchasing Behavior: An Experimental Study[END_REF] The problem is often traced back to the fact that ToS and PP are contracts, and contracts are typically written by lawyers and for lawyers, even though they regulate the mutual interest and relations of lawyers' clients. [START_REF] Berger-Walliser | Promoting business success through contract visualization[END_REF][START_REF] Rossi | From Words to Images Through Legal Visualization[END_REF][START_REF] Rossi | A Visualization Approach for Adaptive Consent in the European Data Protection Framework[END_REF] In a comprehensive analysis of privacy-related empirical research, Acquisti and colleagues [START_REF] Acquisti | Privacy and human behavior in the age of information[END_REF] have identified three recurring themes. First, users are uncertain about what privacy trade-offs entail. Second, privacy decisions and behavior are always dependent on context. The same person can manifest widely different preferences in slightly different situations. Third, people or groups with more insight into the factors that determine privacy decisions can influence the behavior of others (and thus change one's individually manifest decisions). This perspective sheds light on previous research results suggesting that people neglect privacy issues [START_REF] Zhao | Privacy Languages: Are We There Yet to Enable User Controls?[END_REF][START_REF] Schaub | A Design Space for Effective Privacy Notices[END_REF][START_REF] Cranor | User Interfaces for Privacy Agents[END_REF], or that they control privacy threats by such strategies as falsification, passive reaction, and identity modification. [START_REF] Rea | Protecting Personal Information Online: A Survey of User Privacy Concerns and Control Techniques[END_REF].

Earlier GDPR-related research underlines the importance of personal data management tools for users to take actual control of their data. [START_REF] Bus | Personal data management -a structured discussion[END_REF] More recent research work discusses the available kinds of solutions, paradigms or technical support for this. In a survey of current technological solutions for processing personal data, Carvalho and co-authors [START_REF] Carvalho | How to Express Explicit and Auditable Consent[END_REF] study the ways how consent is affirmatively expressed. These include consent by electronic signature, consent sent by email or SMS, consent by access code, consent by confirmation buttons, and several others. All of them have risks, some more than others. Another study by Politou and co-authors [START_REF] Politou | Forgetting personal data and revoking consent under the GDPR: Challenges and proposed solutions[END_REF], analyzes two high-impact rights defined by GDPR: consent revocation and the right to be forgotten. The authors underline software implementation challenges associated with both, and conclude that one of the main reasons for the fact that very few companies are now capable of complying to GDPR is that GDPR provides "little if any technical guidance for entities that are obliged to implement it." [p. 15] One possible solution, they think, is to develop low-level implementation guidelines and business-wide requirements modelling.

Regarding usability and interaction design in the PDP domain, earlier work by Pettersson and co-authors [START_REF] Pettersson | Making PRIME Usable[END_REF] reports on an extensive study with different user interface paradigms for privacy-enhanced identity management. One paradigm differentiates users' roles (what they are doing), and typically assigns pseudonyms to each role. Users can then choose which role they want to play when privacy decisions must be taken. Another paradigm differentiates users' context relations (with whom they are interacting), which allows for bookmarking privacy decisions along with website addresses, for example. Finally, the third paradigm associates privacy preferences with physical locations (it maps privacy options). Every paradigm opens up different interaction design solutions and has specific usability testing determinants that researchers must keep in mind while investigating user behavior.

Regarding usability research specifically or more closely related to GDPR, Renaud and Shepherd [START_REF] Renaud | How to Make Privacy Policies both GDPR-Compliant and Usable[END_REF] have compiled a list of previously proposed guidelines that can respond to GDPR compliance requirements. The authors have included some of their own to the list. Moreover, interdisciplinary work taking HCI and legal factors into consideration, address the use of contract visualizations and icons [START_REF] Rossi | From Words to Images Through Legal Visualization[END_REF][START_REF] Rossi | A Visualization Approach for Adaptive Consent in the European Data Protection Framework[END_REF] to simplify the legalese and the complexity of concepts and terms in ToS and PP statements. We should finally note that machine learning and AI techniques have also been explored to face the challenges of usable GDPR compliance. For example, some studies propose to automate the evaluation of published terms and policies. [START_REF] Contissa | Claudette meets GDPR: Automating the evaluation of privacy policies using artificial intelligence[END_REF][START_REF] Tesfay | PrivacyGuide: Towards an Implementation of the EU GDPR on Internet Privacy Policy Evaluation[END_REF] Others propose to summarize ToS and PP content, and use it to support question answering dialogs with users. [START_REF] Zaeem | PrivacyCheck: Automatic Summarization of Privacy Policies Using Data Mining[END_REF] 3

The Contrastive Study

The goal of our contrastive study was to examine the spectrum of evolution in interaction design for PDP communication and action, in actual and comparable online applications. There are different approaches to covering the change from before to after data protection regulations. One of them is temporal (historical, diachronic). Another is spatial (structural, synchronic). The former analyzes the same set of objects as they evolve over time, while the latter analyzes different sets of objects, which are at different evolutionary stages, at the same physical point in time. For convenience, we chose the structural, synchronic approach. In addition to avoiding the costs of longitudinal studies with evidence being traced back to two or more years past, this alternative also allowed us to discount the change of cultural attitude toward personal data protection during the historical period comprised by a longitudinal approach. In our synchronic perspective, we used the current cultural context of the two sets of analyzed objects, namely the post-legislation interaction design of European websites, and the pre-legislation design of comparable non-European websites.

The objects of the study

The objects of our study were four supermarket websites in Portugal -Continente (www.continent.pt), Froiz (www.froiz.pt), Pingo Doce (www.pingodoce.pt), and Jumbo (www.jumbo.pt) -and four equivalent ones in Brazil -Zona Sul (www.zonasul.com.br), Extra (www.deliveryextra.com.br), Super Prix (www.superprix.com.br), and Pão de Açúcar (www.paodeacucar.com). Together they constitute two mutually exclusive subsets of objects. The Portuguese websites were inspected in January 2019, when GDPR had been effective for more than seven months. The Brazilian websites, inspected on the same dates, demonstrate the state of affairs seventeen months before Brazilian businesses had to comply to the national data protection legislation.

The comparability of objects in both subsets was established by the following criteria. First, all objects belong to the same business sector. Second, in all of the websites we could run the same inspection scenario. Third, both countries have current legislation about how businesses collect, control and process their citizens' personal data online. Brazil, however, is not at the same stage of legal enforcement as Portugal. Finally, both countries speak the same language and share much of their cultural characteristics (Brazil has been colonized by Portugal, and has also been the seat of the Portuguese empire from 1808 to 1821).

Semiotic Engineering

The entire study was informed by Semiotic Engineering [START_REF] De Souza | The semiotic engineering of human-computer interaction[END_REF][START_REF] De Souza | Semiotic engineering methods for scientific research in HCI[END_REF][START_REF] De Souza | Software developers as users: semiotic investigations in human-centered software development[END_REF]. By looking at social communication mediated by computer programs that express, on behalf of participating humans, these participants' communicative intent and content to each other, Semiotic Engineering has the advantage of connecting many points and findings that have been addressed separately by previous research.

Our use of Semiotic Engineering concentrated on the concept of metacommunication, (introduced in Section 1) and the three classes of computer-mediated social interaction signs that the theory investigates, namely: static signs, dynamic signs, and metalinguistic signs. They can be used to define different communication strategies, depending on the communication purposes, the context, the means and the modes of interaction made available to the engaged parties.

Before we define each one of the metacommunication sign classes, it is useful to note that in typical communication settings participants alternate between two roles: the role of senders and that of receivers. The meaning of signs that they exchange is rarely (if ever) the same. Yet, communication is possible mainly because of two factors. First, participants typically share a considerable volume of world knowledge, sociocultural practices and values, linguistic competence, and so on. Second, inevitable misunderstanding can frequently be prevented, detected, and corrected during communication, by means of strategies that are vastly employed on a daily basis, by virtually every human being. Therefore, when we talk about the meaning of signs in metacommunication, we should bear in mind that there are always two human parties involved -the system's designers and the users -in addition to a computational mediator, the system's interface. In the following definitions, when talking about the meaning of signs, we refer to the meaning that humans (designers or users) assign to them, which may or may not coincide, but still share substantial elements with one another. When users assign incomplete or incorrect interpretations to static signs, another class of metacommunication signs is typically used to complete and correct such meanings. Dynamic signs are (shorter or longer) sequences of static signs that span over time, most often as the result of user-system interaction. The meaning of the entire sequence cannot be assigned instantly by any static sign present in its initial state. For example, in Fig. 2 we sketch the expression of an extremely short dynamic sign that a first-time user of The Alchemist Store will typically encounter. Its duration spans from the pre-click to the post-click state of the system. As already mentioned, the static sign shown in Fig. 1 gives a first-time user an imprecise (and potentially wrong) idea of what this website's designers mean by "Privacy and Data Protection". However, her interaction shown in Fig. 2 communicates to her new meanings that this system's designers have assigned to the static menu item "Privacy and Data Protection". On the background screen, whose menu entries are seen on the left-hand side of the magnified area of the image, the user gets the message that she can click on the arrowhead to learn more about what she can do regarding privacy and data protection, and she does it. Then, comes the foreground screen, whose menu entries are seen on the right-hand side of the magnified area of the image. The system's response to the user's clicking on "Privacy & Data Protection" communicates additional messages intended by the designers, namely: that she can learn about "[The service provider's] Privacy Policy"; "What data [the service] collects and why"; how she can "Manage [her] data"; and finally, how she can "Get in touch with [them]". Thus, at the end of this tiny sequence of interaction -which constitutes the dynamic sign -the user has new shared meanings with her indirect and asynchronous interlocutors, the system's designers. Metalinguistic signs are orthogonal to other signs. Their distinctive feature is to communicate something about other signs in the interface language. Typical examples of metalinguistic signs include warnings (with signs that refer to dynamic or static signs shown in other states of interaction), tool tips (with signs that help users understand the meaning of the sign that they are pointing at), and other explanatory or informative help messages that appear during interaction. In Fig. 3, we show a different state of the interface for our imaginary website. On the left-hand side of the magnified portion of the image, we see once again the submenu items for the "Privacy & Data Protection" option. The "Manage your data" option is active. On the right-hand side of the magnified portion, we see the sketch of page content accompanied by push buttons, communicating instantly what users can do in order to "Manage [their] data": to View, to Update, to Download, to Delete, to Contest (the use of), to Restrict (the use of), to Request [an] Explanation (about the use or effect of computations upon) their personal data, and to access [their] Requests. The center portion of the image, however, contains text that communicates about the meaning of interface signs on the left-and right-hand side of the image. These are metalinguistic signs. For example, the text informs that "[some] of [the buttons] will allow you to do what you want without human mediation (for example, to download your data)." This is a sign that explains other interface signs. The same occurs with another portion of the text, saying that "[others] (for example, to restrict how we use your data) will require that you fill out and submit a form with your request."

Interaction designers combine static, dynamic and metalinguistic signs to compose several metacommunication strategies with which to get their message across to users. The effect of such strategies can be investigated in depth with specific Semiotic Engi-neering methods, like the Communicability Evaluation Method. [START_REF] De Souza | Semiotic engineering methods for scientific research in HCI[END_REF] In this paper, however, we are not going to investigate empirically how users receive and interpret the designers' communication. We will only characterize, based on empirical semiotic evidence, how metacommunication is expressed by the designers, then discuss the range of potential effects that can be analytically expected to follow from such expressions. As an example of what we mean by analytical effects, compare the metacommunication message communicated through the mockup in Fig. 4 with that communicated through the mockup in Fig. 1. Regardless of other merits or flaws in each design (which will not be discussed in this paper), even without asking the users, it is analytically evident, by the mere presence and arrangement of static interface signs, as well as their conventional meaning, that data protection is more salient in the communication expressed by the designers of the interface in Fig. 1 than in metacommunication expressed by the designers of the interface in Fig. 4. In particular, regarding the latter, because the design uses static signs that have been long seen on website interfaces prior to GDPR (cf. "Terms of Use" and "Privacy Policy" at the very bottom of the page), the message conveyed by this specific portion of design suggests that there is nothing new in post-GDPR design in this website.

Method

Semiotic Engineering methods are interpretive (qualitative), and explore the meaning of interface and interaction signs for both the producers (designers) and consumers (users) of digital technology. [START_REF] De Souza | Semiotic engineering methods for scientific research in HCI[END_REF][START_REF] De Souza | Software developers as users: semiotic investigations in human-centered software development[END_REF] The contrast between intended and perceived meanings in metacommunication is one of the richest results that Semiotic Engineering methods can yield. Yet, studies focused solely on the emission or the reception of metacommunication can also reveal the effects of certain semiotic features of algorithmically-mediated social communication between humans.

In this study we focused on the emission of metacommunication, that is, on the designers' expression of their message to users. The evidence for semiotic engineering analysis was collected by means of an interactive walkthrough of the interface, where the analyst played the role of a first-time visitor to the website, guided by the content of the following inspection scenario:

Antonio, a business administrator in his early fifties, is spending vacations with friends and family in a nice region of his native country that he has never been to in his entire life. Tomorrow, the group will have a barbecue in the front garden of the house they are renting, and Antonio is in charge of buying snacks and drinks for ten people. He decides to buy them online, but immediately realizes that the food chain where he usually shops when at home does not provide services in the place where he is now. He must then use a new online supermarket service.

Antonio is extremely careful with personal data protection when shopping. So, before he starts, he wants to learn what data the company collects, for what purposes, how they handle it, and finally what rights he has as the owner of the data.

The walkthrough focused primarily on interaction required to find answers to three sets of questions:

• Data Collection

─ What data is collected? By whom? For what purposes? • Data Access, Correction, Portability and Elimination ─ How can the user access his data? How can he correct it? How can he transfer it to another service provider? How can he delete it (be forgotten)?

• Consent and Explanations

─ What does he have to consent to? Can consent be partial or revoked? How? Is there an explanation for how the automatic processing of his data affects him? Can he understand the explanation?

The analysis consisted of four main steps. Firstly, we looked at how content and interactions are communicated (expressed) by the designers of the analyzed websites through static, dynamic, and metalinguistic signs (cf. subsection 3.2 to see what this means). Secondly, we looked at the distribution of sign classes and characterized the designers' metacommunication strategy. Thirdly, we made an overall assessment of what consequences the designers' strategy might bring about for the quality and effectiveness of GDPR-related communication and action.

The final step of the analysis was to contrast the findings of post-GDPR Portuguese websites and pre-DPL Brazilian websites. Differences and similarities regarding communication strategies and their consequences for users should allow us to appreciate the evolution of interaction design to support users' decisions and actions for personal data protection. The walkthroughs were carried out using Firefox 64.0.2, with the recommended (default) configurations for cookies and security. The browser's interface language was set to Portuguese, which is also the language of the eight inspected websites.

Findings

We begin this presentation of findings by noting that evidence of GDPR-related metacommunication collected during the walkthroughs of all websites is almost entirely made up of metalinguistic signs explaining the properties, behavior, policies, and terms of use of other interaction signs, namely the website's interface for online shoppers. Fig. 5 presents one example of massively textual communication from designers to users about the users' personal data protection rights, and what they should do to exert them. Although this might not come as a surprise, given the novelty of the law and data governance practices, the upshot of the virtual absence of metacommunication achieved with static and dynamic signs (like, for example, the mockups shown in section 3.2) is that users can do little more than read and navigate through long spans of text, rather than directly access and download collected personal data, request the deletion, limitation, or specific restrictions of personal data usage online, as suggested in Fig. 3.

Fig. 5. A typical interface to exert personal data protection rights

Moreover, as can also be seen on Fig. 5, for a first-time visitor, metacommunication is thoroughly opaque regarding how the users' rights are handled by the businesses analyzed in our study. All of the European ones, tell users to send email (Fig. 5 "mediante envio de e-mail") or call a telephone number (Fig. 5 "através de contacto telefónico") to make their requests. In other words, most of the GDPR-related tasks cannot be carried out online, through interaction with the website. As previous research has shown [START_REF] Light | Beyond the interface: users' perceptions of interaction and audience on websites[END_REF], since the early days of e-commerce and e-businesses, users seem to perceive the broader social context (especially the 'people') behind interfaces. This has been evident, for example, with the alternate use of "it" (the interface) and "they" (website owners) when verbalizing interaction with websites. The absence of interaction to achieve GDPR-related tasks is, thus, likely to motivate perceptions that although a website or a system may collect and process users' personal data and online behavior, it has nothing to do with the obligations of data controllers and processors obligations (their obligations). Websites may then be seen (and possibly used) as a protective shield for legally responsible parties. Table 1 summarizes our top-level findings.

Dimensions of Analysis

Portuguese Websites

Brazilian Websites

Users' Rights to Know, Decide, and Act

All four websites addressed the users' rights.

Two of the websites partially addressed the users' new rights.

Interaction Design and Metacommunication Strategies

Very restricted interaction (mainly navigation, scrolling); massive textual communication to users; most action takes place via email or telephone (metacommunication is almost non-existent).

Three of the websites support very restricted interaction (mainly navigation, scrolling); massive textual communication to users; action takes place via email, chat or telephone (metacommunication is almost non-existent). One website provides a presumably intelligent assistant. PDP-related Q&A is, however, very poor.

Pre-and Post-Legislation Contrast

Although content (information design) is clearly different before and after PDP law is enforced, interaction design is not different. Moreover, even if legislation empowers users to decide when to share personal data and entitles them to take several actions to manage such data, interaction design does not allow them to do so with the same ease and agility as they can do their online shopping transactions.

Table 2 summarizes the main features of European websites regarding the use of cookies. This is the most striking post-GDPR difference for first-time users, and also one of the few where simple static and dynamic signs fully achieve a PDP task. The middle column shows that the phrasing of messages (translated by the author) underlines the advantages of using cookies, and in some cases suggests that users can not accept to use cookies. Although they can technically do it, if they care to read lengthy textual instructions and follow links to web browsers' documentation on how to block cookies, once they load the current website home page, cookies are immediately in use with default browser configurations. Moreover, most cookie notifications are placed at the bottom of a browser's screen laden with animations advertising products and discounts. These will most likely distract the user's attention away from relevant PDP information.

Jumbo (PT)

"We use cookies, of our own and third parties, to enhance your navigation experience and to show you publicity oriented to your preferences and navigation habits.

Click on 'Accept' to confirm that you have read this and that you accept our Cookies Policy. Accept" Location: POP-UP HOVERING ON THE RIGHT-SIDE OF THE BROWSER'S WINDOW

If the user clicks on the "Cookies Policy" link, he navigates to a webpage with typographically organized information about cookies. The problem is that the pop-up can only be closed by clicking on 'Accept'. The pop-up stays in front of the content which should help the user decide (see Fig. 7). The practical effect is that of a nagging splash screen to persuade users to act as the website owners expect. Brazilian websites do not warn the users about the use of cookies (which they all use). The irony is that, even though European websites warn their users about it, users have no option to say "no", at least to the first load of cookies placed when they hit the home page of the analyzed websites. This communication problem has more to it than meets the eye. In these websites, cookie control is the result of interactions with web browsers, not web servers. Therefore, although metacommunication is carried out in one channel, one context, and with two fairly defined interlocutors (the user and the ecommerce 'website'), a silent third party who is mediating the entire process -a web browser -is the only one that can effectively do something if users do not agree with the website's terms of cookie use. The consequence for communication and user experience may is that, if users want to communicate with the online shopping website on different terms, they cannot tell it to the website. They have to tell it to a silent mediator, who suddenly steps into the scene. This situation is very similar to the one presented in Table 1, where communication needed to turn the users' rights into full effect is systematically directed to mediators that can only be reached by email and telephone.

Further relevant PDP-related evidence comes from a Brazilian website, Super Prix, which uses a different pattern of metacommunication. Instead of the plain navigationscrolling option to 'learn more' about ToS and PP, Super Prix initially offers interaction with an 'intelligent assistant'. At first, if the user clicks on an ostensive "May I help?" button floating on the side of the page, a pop-up window is shown encouraging users to just ask ("Perguntar") what they want to know. The added arrow on the right side of the screenshot image in Fig. 8 indicates the location and design of the pop-up dialog. Intelligent assistance is more explicitly invoked when users follow the link to this website's Privacy Policy. In Fig. 9, however, we show an example of the assistant's behavior when asked: "What do you have to offer re: Personal Data Protection" (author's translation from Portuguese). The user gets two links to information: "What happens with my credit card data?" and "What must I do to change my registered data?". These links are the answer to several other questions like: "May I erase my data?", "May I see what data you collect?", and so on. Beneath the brittle chatbot cover, Fig. 9 also demonstrates the tendency to direct conversation to non-algorithmic interaction. The other tabs to the right of "Atendimento Inteligente" (Intelligent Assistance) are: "Fale Conosco" (Contact, via email) and "Atendimento via Chat" (Online Chat), with human intervention. The findings of our contrastive study can be grouped in three clusters. The first one refers to underprovided online opportunities for users to exert their personal data protection rights while interacting with the analyzed websites. In all cases they are instructed to use email and telephone lines to do it. The second refers to the uncontrolled mediation of web browsers in metacommunications regarding the use of cookies. Consent conversations between users and websites (speaking for their designers, developers and owners) are only consistent if users accept that websites use cookies. If they don't, they must talk to somebody else (in this case, their browser's configuration interface). Finally, we also found evidence that intelligent conversational agents are not yet an option to inform and guide users in their attempts to know how businesses handle their GDPR obligations. All relevant information, steps and decisions relative to enforcing data protection rights are explicitly directed to human-to-human communication channels like email and telephone lines. Algorithmic mediation, which has long been in place for e-commerce -a comparable data-sensitive and legally ruled application area -is clearly not used. In the next section we will discuss these findings and present our conclusions about the significance of this study.

Concluding Remarks

The qualitative study presented in this paper has not been designed to answer questions like "how has interaction design changed after GDPR?", or "how do e-businesses handle their clients' data protection rights online?" in a generalizing sense. The validity of this study is limited by the analysis of only a small set of websites, the contingency of walkthroughs guided by a specific scenario, and the researcher's inevitable interpretation biases. However, as qualitative methodology requires, the researcher has strived to discount such limitations. The adopted strategy has been to use an explicit orienting theory throughout the process. Semiotic Engineering has provided not only the initial categories of analysis (with the concept of metacommunication and the three classes of signs that are used to compose designer-to-user metacommunication messages), but also a framework to organize sociotechnical relations among parties involved in PDPrelated interactions and transaction online. The following paragraphs should show that this study's main contribution is to support the elaboration of qualified hypotheses for subsequent predictive (or non-predictive) more general inquiries with larger samples of interactive systems that collect, store, and process their users' personal data. The findings reported in section 4 are themselves part of the meanings that might be inferred from metacommunication by more reflective users. For instance, users might ask what the owners and producers of the analyzed websites mean by declining to engage in PDP-related interactions in the same way as they engage in buying and selling interactions. The just as interesting reverse question could be asked by reflective interaction designers: What might users take this strategy to mean?

The Semiotic Engineering perspective used in the study can also add significant elements to the current debate on privacy by design [START_REF] Colesky | A Critical Analysis of Privacy Design Strategies[END_REF][START_REF] Cavoukian | Privacy by design: the definitive workshop[END_REF] and usability aspects of GDPR-related interactions online. Because it takes metacommunication as its object of investigation, and metacommunication involves software producers, software users, and software itself, this theory can shed light on certain aspects of current scientific discussions that are not necessarily framed in connection with one another.

The three classes of signs investigated by the theory (see subsection 3.2) establish different conditions of meaning making in HCI. Static signs support instant meaning making, often associated with intuitiveness and ease of use. Metalinguistic signs, in turn, support indefinitely many levels of referential meaning making, which can augment or correct previous meanings assigned to the interaction objects in reference. It is the class of dynamic signs, however, that creates the most complex and intriguing conditions for meaning making. We will refer to this as algorithmically-negotiated meaning making. On the one hand, the expression underlines the fact that dynamic signs are controlled by algorithms (computing rules), and are thus inherently akin to what Peircean semioticians refer to as legi signs, or signs that are established by some kind of law. [START_REF] Merrell | Peirce, signs, and meaning[END_REF] On the other, the expression also underlines the fact that human meanings are always negotiated in social communication. A communication sender (S) can never be sure that the communication receiver (R) has captured what she (S) means by a single piece of communication. Likewise, a receiver (R) can never be sure that what he (R) takes the sender's (S) communication to mean is actually what she means. As a result, social communication is full of interpretation checkpoints and verifications, adjustments, corrections, redundancy, explanations, and other meaning-negotiation procedures that cannot, unfortunately, ultimately guarantee that senders and receivers share the same meanings. Certain semiotic theories actually suggest that they never do. [START_REF] Merrell | Peirce, signs, and meaning[END_REF] Computer-mediation, however, creates and enforces meaning stability (or algorithmic meaning) that governs metacommunication between human parties. The algorithm that captures a user's click on the "Accept" ('Aceitar') button on Jumbo's cookie use notification interface (Fig. 7) defines the necessary and sufficient technological conditions for a user's explicit consent to having cookies placed on her device. The same will be true of other algorithms defining the necessary and sufficient technological conditions for users to access, modify, delete or transport their personal data. The problem, as Fig. 7 conveniently demonstrates, is how interaction design communicates to users the meaning of algorithms. The rhetorical effect of a pop-up window that will not disappear unless the user clicks on the "Accept" ('Aceitar') button is to rush users into accepting the terms of service. In other words, interaction design may add meanings to the algorithmic rule that establishes the technological protocol for consent. On the other hand, the walkthrough has shown that the pop-up window is actually preventing users from reading this website's cookie policy (some portions of it are occluded behind the nagging window). If interaction designers did not mean it to happen, it is now the algorithms that are adding (undesired) meanings to the designers' and possibly the owners' intended message, inducing users to accept personal data usage terms without reading them. The challenge indicated by this piece of evidence is that interaction designers and software engineers do not always negotiate models and implementation meanings with one another. [START_REF] De Souza | Software developers as users: semiotic investigations in human-centered software development[END_REF] Thus, if algorithms are to be taken as an expression of the law, not only interaction design, but also software development processes may need new meaning-negotiation tools for design and development teams to compose and express their message in unison and accordance with the owners' intent.

Furthermore, dynamic signs may well be the reason why GDPR and DPL matters in the Portuguese and Brazilian websites we analyzed are channeled to and processed by humans, rather than algorithms. This view connects with Politou and colleagues' research [START_REF] Politou | Forgetting personal data and revoking consent under the GDPR: Challenges and proposed solutions[END_REF], as well as with studies coming from other domains. For example, Katsh's analysis [START_REF] Katsh | Online dispute resolution: Some implications for the emergence of law in cyberspace[END_REF] of the state of the art in online dispute resolutions (ODR) says that in "the earliest forms of [ODR] […] email seemed an appropriate tool for communication between disputants and between disputants and third parties." [p. 7] Now, however, "the role of software has been recognized in discussions of legal doctrine by the expression code is the law." [p.8] Algorithms, as of now, are not ready to stand for GDPR or DPL.

Our future work with Semiotic Engineering is to explore the merits of alternative metacommunication strategies for PDP communication, decision-making, and action. GDPR is only a trigger for research that aims to contribute for greater transparency in the digital world [START_REF] Edwards | Slave to the Algorithm: Why a Right to an Explanation Is Probably Not the Remedy You Are Looking for[END_REF], striving to enable ethics and fairness in power relations established by algorithmically-mediated metacommunication among humans. This is the call we want to make with this work, that as member of the interaction design community, we tell users what is ethically and otherwise important for them to know about their rights, and help developers and owners express what they mean to say more effectively.

Fig. 1 .

 1 Fig. 1. Illustration of a static sign (a side bar menu item magnified for readability) Static signs are those expressed and interpreted instantly. For example, look at Fig. 1, depicting a snapshot of the interface mockup for an imaginary e-commerce web application called The Alchemist Store. The side bar menu item named "Privacy & Data Protection" (see the magnified portion of the image) probably means different things for interaction designers and application users. When they see the phrase "Privacy & Data Protection" followed by the upward arrow, designers know exactly what they mean by it. Users, however, may look at this sign and have only an incomplete (or even an incorrect) interpretation of what it means. For example, users may interpret this

Fig. 2 .

 2 Fig. 2. Illustration of a dynamic sign (side bar menu items magnified for readability)

Fig. 3 .

 3 Fig. 3. Illustration of a metalinguistic sign (side bar and page content magnified for readability)

Fig. 4 .

 4 Fig. 4. Alternative entry page design of The Alchemist Store

Fig. 6 .Fig. 7 .

 67 Fig. 6. Pop-up window with information about cookies in Continente's website

Fig. 8 .

 8 Fig. 8. Brazilian website "free text" interaction when users need help

Fig. 9 .

 9 Fig. 9. Super Prix intelligent assistant behavior

Table 1 .

 1 Overview of findings.

Table 2 .

 2 Overview of freely translated communication about cookies in Portuguese websites.

	Website	Metacommunication Message and	Further Information / Dialog
		Location on Screen
	Continente	"Our website uses cookies to enhance and	If the user clicks on "Learn
	(PT)	personalize your navigation experience.	more", a pop-up window is
		As you continue navigation you consent to	opened with fixed questions
		the use of cookies. Learn more."	about cookies. The answers ap-
		Location: BOTTOM OF BROWSER'S	pear as the user clicks on the ar-
		WINDOW	row control (see Fig. 6).
	Froiz	"This website uses cookies to enhance	If the user clicks on "More infor-
	(PT)	your experience. As you continue to navi-	mation", a new tab is opened,
		gate you agree with such use. If you want	showing a web page with plain
		to know more, see our Cookies Policy. I	textual explanations about cook-
		understand. More information."	ies. The text contains no active
		Location: BOTTOM OF BROWSER'S	links.
		WINDOW
	Pingo Doce	"This website uses cookies and other	If the user decides to check the
	(PT)	tracking technologies to help navigation	Cookies Policy, a new tab is
		and [enhance] our ability to provide feed-	opened, showing a web page
		back, analyze the use of our website, [...]	with typographically designed
		present promotional information about	information about cookies. It
		our services and products, and provide	even includes a link to an inde-
		content for third parties. Check our Cook-	pendent legal consultancy
		ies Policy. I accept."	group's website, where abundant
		Location: BOTTOM OF BROWSER'S	information about cookies is pro-
		WINDOW	vided.

Acknowledgments

The author thanks the Brazilian National Council for Scientific and Technological Development (CNPq) for partially funding this research, with grant #304224/2017-0. She also thanks anonymous Interact 2019 reviewers, her students, and colleagues for insightful comments and suggestions that improved the original version of this paper.