Autonomous vehicles (AVs) have the potential to vastly improve independent, safe, and cost-effective mobility options for individuals with disabilities. However, accessibility considerations are often overlooked in the early stages of design, resulting in AVs that are inaccessible to people with disabilities. Vehicles serving people with disabilities typically require costly aftermarket modifications for accessibility, which may have unforeseen impacts on vehicle performance and safety, particularly in the case of automated vehicles. In this research, we investigate the performance of three autonomous shuttle design configurations: an off-the-shelf shuttle that is not wheelchair accessible, the campus pilot shuttle that is wheelchair accessible, and a new design using wheelchair accessibility foresight. Physics-based simulations performed using MATLAB, ADAMS (Automated Dynamic Analysis of Mechanical Systems), and Autonomie demonstrated that the modifications aimed at providing wheelchair access had important implications for vehicle dynamics (e.g., turning radius, pitch, roll), energy consumption (operating range and usage duration), and cost per passenger. A ride comfort analysis was performed using MATLAB to study the passenger’s ride comfort in all three shuttle designs. Energy consumption and lateral dynamic analyses were performed to analyze the operating range and turning radius of the shuttles. Also a brief cost analysis provides insight into the cost implications of post-production modifications. Simulation results indicate aftermarket modifications have a large impact on the vehicle performance and increase the cost per passenger. The campus pilot shuttle design adversely affects the turning radius and reduces the driving range by 38% while the new design makes no compromises in vehicle dynamics or driving range. We conclude that if wheelchair access and related accessibility considerations are incorporated in the design phase, the adverse performance of aftermarket modifications can be avoided.