1. A computer implemented method of operating a navigation system comprising: obtaining a request to calculate a pedestrian route from an origin to a destination for travel by a pedestrian; obtaining a walking preference for the pedestrian route identifying a feature of the pedestrian route; accessing data representing at least one pedestrian path from a geographic database associated with the navigation system, wherein the data representing the pedestrian path includes lighting level attribute information for the pedestrian path; determining a valid solution pedestrian route from the origin to the destination comprising a series of connected pedestrian paths that support the walking preference.