Self-propelled modular transporter

A self-propelled modular transporter or sometimes self-propelled modular trailer (SPMT) is a platform heavy hauler with a large array of wheels which is an upgraded version of a hydraulic modular trailer. SPMTs are used for transporting massive objects, such as large bridge sections, oil refining equipment, cranes, motors, spacecraft, entire buildings, and other objects that are too big or heavy for trucks.

Source: Wikipedia — Self-propelled modular transporter (CC BY-SA 4.0)