Internationally road authorities have an obligation to plan, design, construct, and maintain their road networks, facilitate continued functionality, and promote the safety of traffic on national and provincial road networks. They also have an obligation to provide a reliable, effective, efficient, and integrated transport systems that support the sustainable economic and social development of their countries. Road slopes and associated retaining and support structures are considered national roadwork assets much in the same vein as bridges and the roads themselves. They are therefore an integral part of the road network to be assessed and upgraded in a robust way. This paper details the DER (Degree, Extent, and Relevancy) Defects system for visual assessment of road geotechnical slope assets in Southern Africa. It explains the requirements of inventory data capture, describes inspection methodologies, by whom inspections should be carried out, and details defects against requisite operational standards using matrix tabulation: all with an emphasis on prioritizing geotechnical assets, as listed below which require repair or upgrade: The system is a deduct defect-based system requiring the identification of visual defects and rating these defects in terms of degree (D), extent of occurrence (E) and relevancy (R) together making up the DER Defects system of road slope assessment viz: The essence of the DER Defects system is to identify the most relevant/key slope elements, assess and rate the current condition of each using a series of tabulated matrices designed for that task, and measure these as defects against the best or most favorable level/condition they are required to be.