Road sensor assembly (100, 200, 300) for performing measurements on the surface of a road, wherein the assembly comprises the following: - a disc made of a dielectric of a solid material, - a metal outer sleeve which is provided in or around the dielectric, - a metal inner sleeve which is provided in the dielectric, in the outer sleeve and concentrically with respect thereto, wherein the disc has an outer side which is delimited by the top side which, in use, faces upwards, by a bottom side which, in use, faces downwards, and by a peripheral wall which extends between the top side and the bottom side, characterized in that the assembly furthermore comprises: - an annular top layer on a top side of the disc, which annular top layer extends in the part between the inner sleeve and outer sleeve, connects the inner sleeve and outer sleeve, and is configured to simulate a road surface, - a first printed circuit board provided with electronic components which are electrically connected to the inner sleeve and outer sleeve, and which are configured to determine the electrical conductivity of the top layer and to generate a transmitter signal comprising information representative of the electrical conductivity, - an antenna connected to the electronic components and configured to transmit the transmitter signal, and - an electrical power supply connected to the electronic components for supplying them with electrical power, in that the electrical power supply is a battery which is embedded in the dielectric, and in that the first printed circuit board provided with the electronic components and the antenna are enclosed in the dielectric. - a disc made of a dielectric of a solid material, - a metal outer sleeve which is provided in or around the dielectric, - a metal inner sleeve which is provided in the dielectric, in the outer sleeve and concentrically with respect thereto, wherein the disc has an outer side which is delimited by the top side which, in use, faces upwards, by a bottom side which, in use, faces downwards, and by a peripheral wall which extends between the top side and the bottom side, characterized in that the assembly furthermore comprises: - an annular top layer on a top side of the disc, which annular top layer extends in the part between the inner sleeve and outer sleeve, connects the inner sleeve and outer sleeve, and is configured to simulate a road surface, - a first printed circuit board provided with electronic components which are electrically connected to the inner sleeve and outer sleeve, and which are configured to determine the electrical conductivity of the top layer and to generate a transmitter signal comprising information representative of the electrical conductivity, - an antenna connected to the electronic components and configured to transmit the transmitter signal, and - an electrical power supply connected to the electronic components for supplying them with electrical power, - an annular top layer on a top side of the disc, which annular top layer extends in the part between the inner sleeve and outer sleeve, connects the inner sleeve and outer sleeve, and is configured to simulate a road surface, - a first printed circuit board provided with electronic components which are electrically connected to the inner sleeve and outer sleeve, and which are configured to determine the electrical conductivity of the top layer and to generate a transmitter signal comprising information representative of the electrical conductivity, - an antenna connected to the electronic components and configured to transmit the transmitter signal, and - an electrical power supply connected to the electronic components for supplying them with electrical power, in that the electrical power supply is a battery which is embedded in the dielectric, and in that the first printed circuit board provided with the electronic components and the antenna are enclosed in the dielectric.