PURPOSE: To ensure melting of snow and prevention of freezing by installing many snow melting boards, each of which incorporates a radiating pipe and lattice-shaped reinforcing bars, on the road bed so that the adjacent snow melting boards are placed at the same height, pouring a filling material on the bottom surface to secure the snow melting boards to the roadbed, and allowing water to flow in the radiating pipe.

CONSTITUTION: A particulate material is placed and rolled on the roadbed dug to an appropriate depth, and many snow melting boards 3 incorporating a radiating pipe and lattice-shaped reinforcing bars are installed. The height of snow melting board 3 placed side by side is adjusted by using leveling adjuster 11 installed on the bottom of snow melting board 3. The snow melting boards 3 are connected at the same height by inserting liners into recesses 4 for corner alignment disposed at four side corners. At the side of snow melting board 3, a radiating pipe inlet 6 and a radiating pipe outlet 7 are connected by a connecting member 8 to form a set of snow melting boards, and communicate with a water supply main pipe 9 and a return main pipe 10, respectively, to allow underground water to flow for melting snow. This method has high workability and ensures satisfactory prevention of freezing.