The Wibau-SL process was developed as a means of producing bituminous materials more economically than by conventional processes; This is achieved because the process does not require elaborate dust-suppression equipment and, as a consequence, operating costs are lower. This report describes mixing and laying trials of bituminous materials produced by the Wibau-SL process. The aggregates used in the trials included limestone, basalts, gravels, slag and natural sands and the binders were petroleum bitumens and pitch bitumens of penetration grades. The materials successfully produced included rolled asphalt wearing cources and basecourses, dense roadbase and wearing course macadams, open-textured macadams and fine cold asphalt