349.02 Police and traffic officers to enforce law.
(1) It is the duty of the police, sheriff's and traffic departments of every unit of government and each authorized department of the state to enforce chs. 346 to 348 and 350. Police officers, sheriffs, deputy sheriffs and traffic officers are authorized to direct all traffic within their respective jurisdictions either in person or by means of visual or audible signal in accordance with chs. 346 to 348 and 350. In the event of fire or other emergency, police officers, sheriffs, deputy sheriffs and traffic officers and officers of the fire department may direct traffic as conditions may require notwithstanding the provisions of chs. 346 to 348 and 350.
(2)
(a) Notwithstanding sub. (1), a police officer, sheriff, deputy sheriff, traffic officer or motor vehicle inspector may not stop or inspect a vehicle solely to determine compliance with a statute or ordinance specified under par. (b) unless the police officer, sheriff, deputy sheriff, traffic officer or motor vehicle inspector has reasonable cause to believe that a violation of a statute or ordinance specified under par. (b) has been committed. This paragraph does not limit the authority of a police officer, sheriff, deputy sheriff, traffic officer or motor vehicle inspector to make an arrest or issue a citation for a violation of any statute or ordinance specified under par. (b) observed in the course of a stop or inspection made for a lawful purpose. This paragraph does not apply to a traffic officer or motor vehicle inspector in the performance of duties under s. 110.075 (2).
(b) The statutes and ordinances covered under par. (a) are all of the following:
1. This chapter and local ordinances enacted under this chapter.
2. Chapter 961 and local ordinances that strictly conform to s. 961.573 (1) or (2), 961.574 (1) or (2), or 961.575 (1) or (2).
3. Chapters 341 to 346.
4. Local ordinances enacted under s. 59.54 (25) or (25m) or 66.0107 (1) (bm).
(c) Notwithstanding par. (a), a law enforcement officer may not stop a vehicle solely because the vehicle's color differs from the color stated in the application for registration of that vehicle. This paragraph does not limit the authority of a law enforcement officer to issue a citation for improper registration of a vehicle whose color differs from the color stated in the application for registration of the vehicle, if the difference is observed in the course of a stop or inspection made for other purposes.
(3)
(a) In this subsection, “photo radar speed detection" means the detection of a vehicle's speed by use of a radar device combined with photographic identification of the vehicle.
(b) Notwithstanding sub. (1), the state and local authorities may not use photo radar speed detection to determine compliance with any speed restriction imposed by s. 346.57, 346.58, 346.59, 346.595 or 349.11 or a local ordinance in conformity therewith.
History: 1971 c. 277; 1987 a. 34, 399; 1991 a. 39, 269; 1993 a. 246; 1995 a. 113, 201, 448; 1999 a. 90; 1999 a. 150 s. 672; 2003 a. 193; 2005 a. 116.
While it is clear that ss. 110.07 and 110.075 authorize the traffic officers of the state patrol and DOT to make stops and inspections and perhaps arrests for equipment violations, nothing in these statutes limits local law enforcements officers' powers to do so. A city police officer is a traffic officer under s. 340.01 (70), and because s. 110.075 provides that any traffic officer can stop and inspect vehicles for violations of ch. 110 or rules issued under ch. 110, and because sub. (2) permits a police officer to enforce a city ordinance violation upon reasonable basis to believe a violation has occurred, a city officer had authority to make a stop for violation of an ordinance adopting a safety rule. State v. Bailey, 2009 WI App 140, 321 Wis. 2d 350, 773 N.W.2d 488, 08-3153.
In case of an emergency, a sheriff has the power to temporarily close any highway in the county and to divert traffic. 67 Atty. Gen. 335.