What is encompassed within the term "pavement structure"?

The term "pavement structure" specifically refers to the layers that comprise the roadway designed to support traffic loads while providing a smooth driving surface. This includes the pavement itself, which serves as the top layer exposed to traffic, as well as the base courses and subbase courses positioned beneath it. These layers are essential for distributing the stresses imposed by vehicles to the underlying soil, thereby preventing deformation and ensuring longevity.

In contrast, the other options focus on different aspects of roadway systems. For example, road signs, signals, and traffic control devices are vital for regulating traffic flow and ensuring safety but do not contribute to the physical structure of the road. The structural framework of bridges and overpasses pertains to different design considerations and is not included in the definition of pavement structure. Lastly, the planning and logistics of road construction involve project management and scheduling, which are critical components of the construction process but separate from the pavement structure itself.