On-road assessment is an essential component of a comprehensive older driver evaluation. However, based on a systematic review of the older driver literature, it appears that the importance of specific elements within an on-road assessment differs depending on the following intended purpose of the evaluation: (a) the detection of impaired drivers; or (b) driver retraining. Moreover, driving rehabilitation specialists identify additional components as important. Directions for future research include the design of an on-road evaluation protocol that incorporates retraining as an integral part of the evaluation process. Through this approach, it may become clear which driving behaviors are amenable to retraining. [ABSTRACT FROM AUTHOR]