N.H. Rev. Stat. § 231:29
The cost of constructing, reconstructing or repairing such highways, streets, roads or traveled ways shall be assessed by the selectmen against the owners of property abutting or served by such facilities in an amount not exceeding the entire cost of constructing, reconstructing or repairing the same, and the amount so assessed upon each such owner shall be reasonable and proportional to the benefits accruing to the land served. Said assessments may be payable in one year or payment may be prorated over a period not to exceed 10 years, in the discretion of the appropriate governing board. All such assessments thus made shall be valid and binding upon the owners of land so abutting or served by these betterments.
RSA 231:29
RSA 234:23-b. 1979, 166:1. 1981, 87:1, eff. April 20, 1981.