Methods and Systems for Determining Safe Return Range

A method is disclosed for determining and displaying an area comprising a plurality of locations that can be reached by a person or vehicle from a departure node or current position while still reaching a destination node or home location given the initial value at the departure node or current position of a parameter that constrains the distance travelable by the person or vehicle. The method may be implemented on a mobile device such as a portable navigation device and/or on a server or computer, or may be provided as a computer program product.