Driving is a complex task which requires the interaction of multiple higher level cognitive skills, each of which can be affected by experience, age, and cognitive impairment. Assessing at-risk drivers can be done via pre-screening tests and on-road measures to identify any decrements in fitness to drive. This thesis found that experienced drivers responded more slowly (Mean RT = 799.97ms, p = .03) on a measure of executive function (Stroop Colour Word test) and reported greater confidence in their driving ability (Mean rating = 7.7, p < .005) than novice drivers. Older adults were found to have longer response times in a measure of attention (Attentional Network Task, p = .004), and of executive function (Stroop Colour Word test, p < .005), and performed less well in an off-road driving measure (Useful Field of View subtest 3, p = .001) than younger adults. These findings demonstrate significant differences in some cognitive abilities as a result of driving experience and age; additionally, we found that the Stroop Colour Word test should be considered as a more sensitive measure of executive function in pre-screening driving batteries. Finally, this thesis developed a standardised on-road driving test (Maynooth On-Road Driving Assessment [Morda]) with good inter-rater reliability overall (Cronbach’s α = .97) and on four of the five cognitive measures (attention, planning, decision making, and memory). These results and the development of the Maynooth On-Road Driving Assessment further the goal of integrating cognitive assessment with on-road driving tests in a standardised measure of at-risk drivers in Ireland.