In some embodiments, the present systems include, consist of, or consist essentially of a roadarm having a first end, a second end, and an opening near the first end; where the second end is configured for attachment to a passive spring (e.g., an air spring, a coil spring, a compressible fluid spring, or a leaf spring), and the opening is configured for interchangeable use with any of: (a) a passive suspension system damping element, (b) a semi-active suspension system damping element, and (c) an active suspension system actuator. Other systems are included, such as those with common control systems for the active and semi-active suspension systems. Methods relating to such systems.