With the rapid development of autonomous driving technology, ensuring that elderly drivers and passengers can adapt to and effectively use these systems has become a pressing issue. This paper explores the impact of the “understanding gap,” “technology gap,” and visual fatigue on the situational awareness and control perception of elderly drivers and passengers in an autonomous driving environment. Through experimental design, participants were induced into different fatigue states to assess their perception of vehicle speed and the differences in situational awareness and control perception under various adaptive information presentation modes (such as text, images, and text-image fusion). The results indicate that fatigue significantly affects the situational awareness and control perception of elderly drivers and passengers, and adaptive designs can mitigate this impact. Specifically, in high-fatigue states, designs based on dynamic feedback and hierarchical information display significantly improve the elderly's response speed and accuracy to environmental changes. This paper provides theoretical support for the design of autonomous driving systems and emphasizes the unique needs of the elderly population in autonomous driving scenarios.