N.H. Rev. Stat. Ann. § 231:57

Each town shall, at each annual meeting, raise and appropriate for the repair of highways and bridges within such town a sum not less than 1/4 of one percent of the valuation of the ratable estate on which other taxes are assessed by the town; and in addition thereto may raise as much more as it may deem necessary; providing, that no town shall be required to raise under the provisions of this subdivision more than $50 per mile for the repair of highways and bridges regularly maintained within the town.