Every stop sign, traffic device, or traffic signal erected on any public highway shall be deemed lawfully erected and maintained and to conform to standards set by the commissioner of transportation and approved by him as to type, size, installation and method of operation, until the contrary is proven, in all cases, civil or criminal.
Source. 1945, 188:1, part 19:5. RSA 249:9. 1981, 87:1. 1985, 402:6, I(b)(7).