N.H. Rev. Stat. § 229:1
Highways are only such as are laid out in the mode prescribed therefor by statute, or roads which have been constructed for or are currently used for motor vehicle, bicycle, or pedestrian public travel over land which has been conveyed to a city or town or to the state by deed of a fee or easement interest, or roads which have been dedicated to the public use and accepted by the city or town in which such roads are located, or roads which have been used as such for public travel, other than travel to and from a toll bridge or ferry, for 20 years prior to January 1, 1968, and shall include the bridges thereon. Highway does not include any bridge, trail, or path intended for use by off highway recreational vehicles, as defined in RSA 215-A:1, or snowmobiles, as defined in RSA 215-C:1.
RSA 229:1
RS 53:7. CS 57:7. GS 68:8. GL 74:8. PS 67:1. PL 74 :1. RL 90:1. 1943, 57:1. 1945, 188:1, part 1:1. RSA 230:1. 1967, 283:1. 1981, 87:1, eff. April 20, 1981. 2017, 156:123, eff. July 1, 2017.