The invention provides a highly durable surface coating intended to inhibit the formation of ice at sub-0° C. temperatures as well as reduce the accumulation of dirt and insect debris to a vehicle surface upon impact. A continuous, durable matrix surrounds both low-surface-energy (low-adhesion) material inclusions as well as hygroscopic material inclusions. Some variations provide a low-friction, low-adhesion material comprising: a durable continuous matrix; a plurality of first inclusions, dispersed within the matrix, each comprising a low-surface-energy polymer; and a plurality of second inclusions, dispersed within the matrix, each comprising a hygroscopic material. The matrix and the first and second inclusions form a lubricating surface layer in the presence of humidity. Other variations employ a durable continuous matrix and a plurality of inclusions, dispersed within the matrix, each comprising a low-surface-energy polymer surrounding a hygroscopic material. Coating precursors and methods of forming final coatings are also described.