On July 5th, 2012 TrafficQuest organised, together with TRAIL and Delft University of Technology, a masterclass on human behaviour in traffic models. Over the past years a lot of knowledge and data on traffic behaviour have become available, but it does not yet find its way into commonly used traffic models. From dynamic macroscopic planning tools to microscopic simulation models: all models contain assumptions about human behaviour. But how realistic are these assumptions? And what are the consequences? During the masterclass 4 experts shared their opinion about this topic with about 40 participants.