N.H. Rev. Stat. § 246:10
Every railroad shall construct, or improve, and operate and maintain at every grade crossing of its railroad with another railroad or highway such warning signs, gates or other protection; it shall so regulate the speed of its trains across any grade crossing and it shall give such appropriate warning of the approach of its trains to any grade crossing as the department of transportation, after notice and hearing, may find necessary in the interest of safety of the railroad or of the public; provided, however, that cost of constructing or improving such warning signs, gates or other protection shall be apportioned in accordance with the provisions of RSA 373:3. The railroad shall maintain signs, signals, gates or other equipment installed within the limits of its right of way, after the installation thereof.
RSA 246:10
1885, 98:1, 3. PS 159:4. PL 249 :13. RL 299:16. 1951, 203:58 par. 10. RSA 373:10. 1985, 402:6, I(e)(5).