A road safety barrier assembly for detecting an impact of a vehicle, comprising: a road safety barrier; wherein it comprises: an electric circuit that can be supplied with direct current, comprising: an outward electric cable for feeding the electric current and a return electric cable for the return of the electric current, the outward electric cable and the return electric cable both running along the road safety barrier; a plurality of impact detecting sensors which are distributed along the road safety barrier, so that each impact detecting sensor of the plurality of impact detecting sensors is able to detect an impact of a vehicle against a portion of road safety barrier in which the impact detecting sensor is located; each impact detecting sensor of the plurality of impact detecting sensors being connected to the electric circuit so that, if it detects an impact of a vehicle against the portion of road safety barrier in which it is located, it causes a switching of the electric current coming from the outward electric cable towards the return electric cable at the same portion of road safety barrier; characterised in that it comprises further a voltage measuring device which is arranged so as to measure a voltage value between the outward electric cable and the return electric cable upstream of the plurality of impact detecting sensors; and a control unit which is predisposed to receive a signal indicating the voltage value measured by the voltage measuring device and which is configured to calculate the distance between the voltage measuring device and the portion of the road safety barrier at which the impact took place, by applying Ohm's Law. an electric circuit that can be supplied with direct current, comprising: an outward electric cable for feeding the electric current and a return electric cable for the return of the electric current, the outward electric cable and the return electric cable both running along the road safety barrier; a plurality of impact detecting sensors which are distributed along the road safety barrier, so that each impact detecting sensor of the plurality of impact detecting sensors is able to detect an impact of a vehicle against a portion of road safety barrier in which the impact detecting sensor is located; each impact detecting sensor of the plurality of impact detecting sensors being connected to the electric circuit so that, if it detects an impact of a vehicle against the portion of road safety barrier in which it is located, it causes a switching of the electric current coming from the outward electric cable towards the return electric cable at the same portion of road safety barrier; characterised in that it comprises further a voltage measuring device which is arranged so as to measure a voltage value between the outward electric cable and the return electric cable upstream of the plurality of impact detecting sensors; and a control unit which is predisposed to receive a signal indicating the voltage value measured by the voltage measuring device and which is configured to calculate the distance between the voltage measuring device and the portion of the road safety barrier at which the impact took place, by applying Ohm's Law.