1. According to the reasoning of the judgment below, the court below presumed that the defendant has a duty to return unjust enrichment due to the defendant's occupation and management of the land in this case, and judged the amount of the land in this case to be excluded from the development gains. The land in this case excluded the development gains from the construction of the road in this case due to the failure to form the price on the road itself, and estimated the development gains from the construction of the road in this case, and recognized the fact that the inferred price of the land in this case was 28,768,90. The rent rate is reasonable in light of the following facts: (a) the use of neighboring standard land, market interest rate, real estate competition, the intention and use value of the parties concerned, and the rent rate under the State Property Act and the Local Finance Act; (b) the rent rate of the land in this case is inappropriate to apply mutatis mutandis to the subsequent construction of the ditch or its sub-construction as it is, and (c) the compensation rate is calculated annually within the limit of 1/5 to 1/3 of the neighboring land.

2. Where the defendant occupies private land without title as a road, the amount equivalent to the amount of unjust enrichment to be returned shall be calculated by multiplying the basic price of the land concerned by the rent rate. The rent rate to calculate the rent for the land shall be determined by taking into account the rate of national and public bonds, the long-term loan rate of banks, the general public interest rate, the normal interest rate for real estate transactions, the rate of rent for the State Property Act and the Local Finance Act, etc. In addition, it shall be determined by taking into account the loan rate as stipulated in Article 6-2 of the Enforcement Decree of the Act on Special Cases, which shall apply only where the land, etc. necessary for public projects is acquired or used through consultation, such as private roads, etc. prescribed in Article 6-2 of the Enforcement Decree of the Act on Special Cases, which shall only apply to the acquisition or use of the land, and the amount of damages equivalent to the rent shall not be calculated based on the estimated price (see, e.g., Supreme Court Decision 90Meu19251, Aug. 24, 1993).

3. Therefore, in the case where the court below sought the return of unjust enrichment from possession without title, it cannot be deemed appropriate to set the rent rate in consideration of the provisions of the Enforcement Rule of the above Act of the Act on Special Cases, which applies to private roads, etc. In addition, the court below did not have any data which can be recognized that the estimation of the rent rate is 288,768,90 won, and that the estimation of the rent rate is 288,768,90 won, considering the evidence No. 10, which the court below cited, around the end of 1991, the appraisal price of the land of this case was 288,768,90 won, and the court below seems to have considered it as the basis of fact-finding. If the appraiser's 10 entries of the evidence No. 1 of this case were to be considered as a ditch in assessing the land of this case, the appraisal rate of the land of this case is to be considered as the actual use rate or the price of the rent of this case at the time of this case.

4. However, the court below recognized the basic price of the land of this case as 288,768,90 won on the basis of the appraisal result by the above appraiser and evaluated the appraisal of the basic price of the land of this case as 288,768,90 won, but rejected the appraisal of the rent rate in consideration of the reasons already considered in the calculation of the basic price or the reasons that cannot be the basis for the calculation of the rent rate, and assessed the rent rate much lower than it. This cannot be said to be in violation of the legal principles as seen in the above 2 and 3.

The judgment of the court below is erroneous in the misapprehension of legal principles as to the calculation of the rent rate of the land incorporated on the road, and this point is with merit.

Therefore, the part of the judgment of the court below against the plaintiffs is reversed and remanded. It is so decided as per Disposition by the assent of all participating Justices.

Justices Kim Jong-soo (Presiding Justice)