Mobility as a Service (MaaS) is a concept that integrates public transport and other access based mobility services into one easy to use platform. For users this means that they no longer have to do large investments while still having access to transport. They can perform door-to-door journeys in a way that suits their needs at a specific time. Transport providers can use this integrated system to create e network that serves the required area and its travellers in a more efficient way. Society can benefit from MaaS as it is centred around transport modes that have a lower negative impact on the urban environment, and use less space. RET is currently looking to introduce a Mobility as a Service-system in the Netherlands. They are working to create the technical requirements for such a platform, and to develop partnerships with other stakeholders like access based mobility providers and societal partners. They however were unsure of who to develop for and what these users want from a MaaS-system. Thus, this thesis focuses on that question. MaaS-journeys should be fast, flexible, reliable, and seamlessly usable. This requires having a high speed, high capacity backbone of trains, metros and lightrail services, supplemented with flexible access based mobility services like shared e-bikes, steps and scooters, and other public transport modes. These journeys should be doable in an easy way: the platform and infrastructure supports a seamless travel experience. There is still a long way to go before a fast, flexible, reliable, seamless MaaS-experience can be realised. Therefore a long-term approach must be adopted by using a design roadmap. This provides the opportunity to work towards the full potential of a MaaS-system by keeping the future in focus. Users should firstly become interested in MaaS and access based mobility through the integration of public transport and other access based mobility services. This creates a more fast and flexible journey. Then, MaaS should work towards providing for routine journeys, and finally towards covering daily urban mobility needs.