Abstract: The subject of the present invention is a new method for designing road asphalts, comprising:—the determination of the optimal bitumen content with compacting experiments using samples made of asphalt mixtures; the optimal bitumen content being the one at which the receptive void volume has a minimum value, depending on the bitumen content; that is, where the compactness of the sample is the highest, and by changing the mass rates in the asphalt mixture, the bitumen content is set to the optimal bitumen content at most. The optimal bitumen content provides the possibility to aim for reaching the highest compactness, i.e. the smallest possible void volume which provides the most favorable fatigue and solidity characteristics.