Stefan van der Spek his specialism is in intermodal transfer points. Main theories within his research covers Transit Oriented Design (TOD), Transport Development Areas (TDA) and Pedestrian Oriented Design (POD). In this specialism urban design is directly connected with mobility and traffic design. Another interest is Liveable Cities: Public Space and Vital City Centres. In both themes the users (people) and flows (traffic) are an essential starting point.