One variation of a method for determining a location of a user includes: at a mobile computing device, receiving from the user a request for pickup by a road vehicle; accessing an optical image recorded by the mobile computing device at approximately the first time; detecting a set of image features in the optical image; accessing an approximate location of the mobile computing device from a geospatial positioning system; accessing a set of known features associated with geographic locations within a threshold distance of the approximate location; in response to detecting correspondence between a first image feature in the set of image features and a first known feature in the set of known features, extrapolating an action geographic location of the mobile computing device based on a particular geographic location associated with the particular known feature; and dispatching an autonomous vehicle to proximal the actual geographic location.