Saudi roads authority details engineering layers of national road network

The General Authority for Roads has disclosed the four primary layers that comprise Saudi Arabia's road network, revealing that roads comprise four successive layers of soil, gravel, and asphalt, each with varying thicknesses and structural purposes. This move is part of the authority's strategy to elevate the quality of the road network, which is pivotal in realizing the objectives of Saudi Vision 2030.

The authority elucidated that the foundation comprises the subgrade layer, capped at a thickness of 30 cm. This base is constructed using gravel and sand devoid of organic matter and must adhere to stringent criteria to guarantee stability and endure substantial traffic pressures. Superimposed on the subgrade is the granular base layer, also capped at 30 cm with high-grade gravel.

This layer evenly disperses traffic loads across the lower layers. Next, the asphalt base layer, not exceeding 20 cm in thickness, alleviates stress on the foundational layers, enhances water runoff, and shields the layers beneath from moisture harm. Finally, atop the asphalt base is the asphalt surface layer, limited to 5 cm in thickness, representing the layer most directly exposed to vehicular traffic.

Its design ensures resilience against pressures and environmental conditions, offering a smooth and secure surface for road users. The authority emphasized that these thicknesses denote the approved maximums but may fluctuate based on the specific technical requirements of each road, considering the anticipated usage, projected traffic volume, and the site's environmental and geographical attributes.

The General Authority for Roads affirmed its continuous endeavors to incorporate advanced technical standards to enhance the road user experience while ensuring unparalleled safety, efficiency, and sustainability. It also underscored its dedication to providing a cohesive and transparent legislative and regulatory framework, including the introduction of the Saudi Roads Code, as part of its mandate in overseeing and regulating the road sector in alignment with the aspirations of Vision 2030.