Abstract: The bitumen/polymer composition comprises a bitumen, an elastomeric polymer vulcanisable with sulphur in an amount of 0.5 to 20% by weight of the bitumen, a sulphur-donating vulcanising agent, a vulcanisation accelerator and a viscosity-reducing agent chosen from water and hydrocarbon oils. The vulcanisation accelerator present in the composition consists of one or more vulcanisation accelerators active at temperatures below 100.degree. C., and the viscosity-reducing agent is used in an amount suitable for rendering the composition liquid at temperatures below 100.degree. C.