Project Summary Mild cognitive impairment (MCI) is often viewed as a transitional state leading to Alzheimer's disease. Drivers with MCI have decreased driving performance as well as steeper declines in driving exposure and driving difficulty. While driving is clearly contraindicated as dementia advances, it is critical to examine to what extent safe driving skills can be maintained in MCI. This is because driving cessation is linked to incident depression, reduced physical activity and healthcare access, and greater risk for long term care placement and mortality. Policies and procedures for detecting at-risk older drivers are either non-existent or remain controversial due to a lack of an evidence-basis. Interventions to aid in maintaining driving fitness are lacking. The Applying Programs to Preserve Skills Study (APPS) was previously funded by NIH (R01AG045154) with data collection complete as of October 2019. APPS is a single-masked randomized clinical trial to evaluate processing speed training on on-road driving skills in persons with MCI as evaluated by a certified driving rehabilitation specialist (CDRS) and backseat evaluator. The vehicle for driving performance was instrumented with a data acquisition system which recorded vehicle kinematics and 5-channel video of the roadway environment and driver. The impact of the APPS visual processing speed training intervention on objectively measured driving performance and behaviors was not an aim in the APPS R01, nor was the collection and analysis of this objective driving data included in the APPS budget. We collected this data in anticipation of applying for funding to specifically analyze these complex, valuable data after the APPS study was complete. Vehicle instrumentation to measure objective on-road and behind the wheel events is a major methodological step forward in understanding declining cognitive abilities and driving. Our research plan has the following aims. Aim 1: To examine cross-sectional and longitudinal associations between cognitive function in older drivers with MCI and on-road driving performance (e.g., speed maintenance, steer steadiness, lane control, turning). Aim 2: To examine the impact of a visual processing speed training intervention on driving performance and behaviors (as described in Aim 1) based on vehicle kinematics and driver behaviors among older drivers with MCI. Aim 3: To examine the association between driving performance in older drivers with MCI (as described in Aim 1) and driving performance ratings by a CDRS, currently the clinical gold standard. All aims will consider the roles of potentially confounding factors. This research will identify potentially aberrant driving maneuvers associated with cognitive impairment in MCI, contributing to the eventual development of a clinical tool to identify older drivers at high-risk for unsafe driving.