Abstract
Separation is a basic principle in transportation. Physical separation based on speed and power differences seems natural to prevent mixing light, slow pedestrian and bicycle traffic with heavy, rapid automobile traffic. Integration in transportation is also necessary, for integration is a basic principle for efficiency in transportation. It is very important to anticipate future situations. Separation is a basic principle to avoid physical conflicts between traffic elements. There is no opposite between separation and integration. For the future there will be new approaches for integrated transportation e.g. electric cars, minibuses, and park and ride systems. For the covering abstract see IRRD 253224.