A process is provided for preparing in aqueous emulsion, a bitumen/polymer binder with a continuous three-dimensional polymeric structure. The process comprises:a) forming a reaction mixture in an emulsion formation zone by feeding to the zone(i) a bitumen-polymer component comprised of a bitumen containing 0.5% to 15%, by weight of the bitumen, of a sulphur-crosslinkable elastomeric polymer, the bitumen/polymer component being in the form of a melt viscosity of not more than 2 Pa.s at the melt temperature,(ii) an aqueous phase containing an effective quantity of an emulsifying system, and(iii) a crosslinking system donating sulphur in a quantity such as to provide 0.5 to 20% by weight of sulphur relative to the weight of the elastomeric polymer contributed by the bitumen/polymer component, andb) maintaining the reaction mixture in the emulsion formation zone at an appropriate temperature until an aqueous emulsion of bitumen/polymer binder is obtained, in which the polymer of the binder is at least partially crosslinked to a three-dimensional structure.The bitumen/polymer binder is useful for coating road surfaces.