As cities are cutting polluting cars off the picture and promoting the use of sustainable transport modes, the number of multimodal journeys that involve more than one transport mode will grow. Intelligent systems and smart assistants will fill in the gap and take their role to guide travelers along their way on the trail of mobility infrastructure weaved in cities., Smart travel assistants will not only enable seamless journeys through navigation, but also make many decisions on our behalf. How should we handle these tools to enrich our multimodal trips while not losing control of the relationship when they are equipped with capabilities to better understand and predict travelers’ needs and behavior? This thesis describes how multimodal travelers plan and make a journey and how to support this process with a personal travel assistant called a travel buddy. During the Mind Mapping session with users, it was found that they want smart assistants to know everything about themselves. However, since they believe machines can’t think like a human, they want to be more involved in customizing routes. On the other hand, there is a responsibility for such apps to deliver only accurate and necessary route options and travel information while making the interaction between a user and an app easy and intuitive. However, simplicity can bring negative consequences such as losing congruence with travel patterns of users by neglecting factors that are important determinants in human decision making. Aiming to establish a collaborative relationship between a traveler/user and a travel buddy, the final prototype depicts a future scenario in which a travel buddy actively learns, and asks for participation, and defines a travel type of a user to optimize the journey together. A defined travel type can be used as a tool for users to observe and reflect on their travel behavior. The impact of defining a travel type can change travel behavior when it’s treated well. This thesis concludes with a manifesto that delivers considerations when developing a travel buddy that will shape future mobility together with users.