Local authorities may, by ordinance, when they deem it necessary for the public safety, install official stop signs at public traveled railroad grade crossings on highways maintained by the respective authorities.
Wis. Stat. § 349.085
Authority to install stop signs at railroad grade crossings
1977 c. 116. 4349.09 VEHICLES - STATE AND LOCAL POWERS
Official source: Wisconsin State Legislature. Reproduced from public-domain Wisconsin statutes; confirm against the official source for the current text. Not legal advice.