To provide a means for preventing snow accretion and freezing of the surface of a road or bridge by using solar energy without requiring electric power nor using a special construction.

Microcapsules, each containing a heat storage material with a melting point of -5 to 15°C, are kneaded into concrete that forms the surface of a road. Preferably, the heat storage material is selected from at least one kind of 13-16C normal paraffin and the microcapsule preferably has a volume average particle size of 1 to 20 μm.