Extension of Edie's Definitions for Pedestrian Dynamics

Consistent definitions of important variables in pedestrian flow dynamics are proposed. They are based on the definition of similar variables for road traffic flow from the 1960's by Edie. The definitions are extended to include multi-class flows where pedestrians move in different directions or have different characteristics. The new definitions provide a foundation of already existing crowd flow models and support their further development and the development of better observation methods.