This paper explores some of the most widely available in-vehicle information technology systems (intelligent transport systems, or ITSs) and discusses their implications for occupational therapy practice. Therapists often evaluate the impact of functional impairment on driving ability and, with an ageing population, the need for such assessments is increasing. Concurrently, ITSs are becoming increasingly common and it is important that their potential effects on both driving task demand and crash risk are considered by therapists when assessing drivers. Interactions between drivers and ITSs are analysed in an information processing framework, highlighting the importance of drivers' cognitive functioning. It is evident that the ability to use an ITS while driving is influenced by a driver's sensory, perceptual, cognitive and motor capacities and skills, all of which are likely to vary with age, disability and/or driving experience. The compatibility of ITS interface design with drivers' capacities and needs is crucial in determining how effectively, and safely, a particular system will be used. Therapists need to analyse interface demands in relation to the ability of individual drivers to cope with or benefit from an ITS, and to consider the potential for calibrating particular products to the specific requirements of individual drivers. It is concluded that many ITSs are at an early stage of development and should not be recommended without critical evaluation of their utility, usability and safety for the intended users. Therapists face the challenge of understanding the parameters and implications of ITSs so that they can assist their clients to optimize their occupational performance despite functional limitations, while also protecting the safety of other road users. Standards related to interface design are still undergoing development, and there is an urgent need for further research to evaluate the impact of vehicle technologies on human behaviour and road safety.