Driving requires several different sets of abilities, the interaction of which is complex. The combination of these factors, rather than any single factor alone, may make it inadvisable to issue a driver's license. Although vision is the predominant source of information for the driver, visual abilities are only one of the factors to be considered when judging the overall driving ability of an applicant. The final determination can only be made through on-the-road evaluation and cannot be based on the evaluation of vision alone. Individual evaluations should include a review of the past driving record and of nonvisual driving-related abilities, as well as observation of on-the-road performance by a qualified driving instructor or driving evaluator.