Sufficient warning of dangerous embankments shall be held to have been given whenever the railing, post, or other warning signs or structures conform to the standards prescribed by the commissioner of transportation and have been approved by him in the manner hereinafter provided.
RSA 231:94
1925, 52:2. PL 89 :2. 1935, 118:2. RL 105:2. 1945, 188:1, part 18:19. RSA 247:19. 1981, 87:1. 1985, 402:6, I(b)(3).