The use of smartphones in cars is a common practice that can result in distracted drivers and accidents. Research has shown that using voice to interact with the devices is the least dangerous solution for users, but its implementation is limited and sub-optimal. Other techniques like proactivity have shown positive results but its presence in products is reduced. This study aims to define, through the synthesis and combination of previous research, a set of guidelines for the implementation of voice interfaces in smartphone apps that can safely offer relevant content to car drivers. Based on a review of the literature on testing for driving solutions, a series of online user evaluations were conducted across potential car drivers. The evaluations consisted of different behavioural scripts for the voice interface, which implemented diverse techniques to interact with drivers, and on the users’ thoughts and impressions. Analysis on the gathered data demonstrates that interacting with drivers through a voice interface and focusing on conciseness, politeness, proactiveness, offering relevant content and transparency of intent are fundamental to keep interactions engaging and relevant, as well as giving a sensation of assurance to the users. Further research is needed to validate the adequacy and safety of these guidelines in a real car environment. / Användning av smartphones i bilar är ett vanligt problem som kan resultera i distraherade förare och olyckor. Forskning har visat att användning av röst för att samverka med enheterna är den minst farliga lösningen för användare, men dess implementering är begränsad och suboptimal. Andra tekniker som proaktivitet har visat positiva resultat men dess närvaro i produkter minskar. Denna studie syftar till att definiera, genom syntes och kombination av tidigare forskning, en uppsättning riktlinjer för att implementera röstinterfacer i smartphone-appar som säkert kan erbjuda relevant innehåll till bilförare. Baserat på en genomgång av litteraturen om testning av körlösningar genomfördes en serie online-utvärderingar av potentiella förare. Utvärderingarna bestod av olika beteendeskript för röstinterfacen, som implementerade olika tekniker för att interagera med drivrutiner och om användarnas tankar och intryck. Analys av de insamlade uppgifterna visade att interaktion med förare genom en röstinterface och fokus på korthet, artighet, proaktivitet, erbjudande av relevant innehåll och avsiktsöppenhet var grundläggande för att hålla interaktioner relevanta och engagerande, samt att ge användarna en känsla av säkerhet. Ytterligare forskning behövs för att validera lämplighet och säkerhet för dessa riktlinjer i en verklig bilmiljö.

<p>On a daily basis drivers have to share the roads with a great number of other road users. To make the driving task possible every driver has to take the intentions and behaviours of other road users into account. In other words, the road users have to interact with each other. The general aim of this thesis was to examine factors that regulate and influence the interaction between road users. To do so, three studies, applying a social psychological approach to driving, were conducted. In the first study it was investigated how the rules of priority, the design of the intersection, and the behaviour of other drivers influence yielding behaviour in intersections. The second study examined driver irritation and its relationship with aggressive behaviours. Finally, in the third study drivers’ attributions of their own and other drivers’ behaviour were investigated in relation to driver irritation. The thesis also includes a minor field study, aiming at examining to what extent informal traffic rules are used in intersections and in roundabouts, as well as measuring the validity of self-reports. The results indicate that, in addition to the formal rules, drivers rely on informal rules based on road design and on other drivers’ behaviour. Drivers also differ with respect to strategies of yielding behaviour. Irritability and aggressive behaviour on the roads appear largely to depend on drivers’ interactions and drivers’ interpretation of the behaviour of others. Some aggressive behaviour is an expression of irritation and may provoke irritation of other drivers. This means that an irritated driver might start a chain reaction, spreading irritation and aggressive behaviour from driver to driver. To diminish irritation and aggressive behaviour on the roads it is necessary to change drivers’ behaviour either by changing the road design or, which is probably a more possible remedy, by changing their general attitudes about driving. By providing drivers with insight into the cognitive biases they are subject to when judging other road users’ behaviour, both driver irritation and aggressive behaviours on the roads probably would decrease.</p>

On a daily basis drivers have to share the roads with a great number of other road users. To make the driving task possible every driver has to take the intentions and behaviours of other road users into account. In other words, the road users have to interact with each other. The general aim of this thesis was to examine factors that regulate and influence the interaction between road users. To do so, three studies, applying a social psychological approach to driving, were conducted. In the first study it was investigated how the rules of priority, the design of the intersection, and the behaviour of other drivers influence yielding behaviour in intersections. The second study examined driver irritation and its relationship with aggressive behaviours. Finally, in the third study drivers’ attributions of their own and other drivers’ behaviour were investigated in relation to driver irritation. The thesis also includes a minor field study, aiming at examining to what extent informal traffic rules are used in intersections and in roundabouts, as well as measuring the validity of self-reports. The results indicate that, in addition to the formal rules, drivers rely on informal rules based on road design and on other drivers’ behaviour. Drivers also differ with respect to strategies of yielding behaviour. Irritability and aggressive behaviour on the roads appear largely to depend on drivers’ interactions and drivers’ interpretation of the behaviour of others. Some aggressive behaviour is an expression of irritation and may provoke irritation of other drivers. This means that an irritated driver might start a chain reaction, spreading irritation and aggressive behaviour from driver to driver. To diminish irritation and aggressive behaviour on the roads it is necessary to change drivers’ behaviour either by changing the road design or, which is probably a more possible remedy, by changing their general attitudes about driving. By providing drivers with insight into the cognitive biases they are subject to when judging other road users’ behaviour, both driver irritation and aggressive behaviours on the roads probably would decrease.