Chapter 347

347.35(3)(am) (am) A motor vehicle may be towed without being equipped with brakes as provided in par. (a) if the gross weight of the towed vehicle is not more than 40 percent of the gross weight of the towing vehicle and the brakes on the towing vehicle are capable of bringing the combination of towing vehicle and towed vehicle to a stop as provided in s. 347.36 (1).

347.35(3)(b) (b) Every full trailer, semitrailer, pole trailer or other towed vehicle required to be equipped with brakes shall be equipped with brake systems of such design and type, and capable of meeting such performance standards, as established by rule of the department.

347.35(3)(c) (c) This subsection does not apply to farm trailers or to disabled vehicles while being towed to a place of repair or to automobiles or trucks while being towed or being transported pursuant to s. 341.47 (1) (b).

347.35(4) (4) Mobile homes and recreational vehicles. No person shall manufacture and no person shall sell a mobile home or recreational vehicle in this state unless such mobile home or recreational vehicle is equipped with brakes adequate to control the movement of and to stop and hold it. No person shall operate on a highway any mobile home registered as a 1940 or later year model or recreational vehicle unless such mobile home or recreational vehicle is equipped with brakes adequate to control the movement of and to stop and hold it.

347.35(5) (5) Implements of husbandry.

347.35(5)(a) (a) No person may operate on a highway any self-propelled implement of husbandry manufactured after February 1, 1985, unless the vehicle is equipped with brakes or other stopping device adequate to control the movement of and to stop and hold the implement of husbandry.

347.35(5)(b) (b) Every self-propelled implement of husbandry required to be equipped with brakes or other stopping device shall be equipped with brakes or a stopping device that meets design, type or performance standards established by the department by rule. The rule of the department under this paragraph shall comply with the applicable standard established by the American society of agricultural engineers.

347.35 History History: 1977 c. 29 s. 1654 (7) (e); 1979 c. 163; 1983 a. 124, 243, 244; 1985 a. 65; 2007 a. 11; 2019 a. 50.

347.35 Cross-reference Cross-reference: See also ch. Trans 308 and ss. Trans 305.17, 305.37, and 305.51, Wis. adm. code.

347.36 347.36 Performance ability of brakes.

347.36(1) (1) Brakes on motor vehicles and brakes on combinations of vehicles shall be capable of bringing the vehicle or combination of vehicles to a stop, under normal conditions, within 50 feet when traveling at a speed of 20 miles per hour.

347.36(3) (3) All required brakes shall be maintained in good working order.

347.36 History History: 1983 a. 243.

347.36 Cross-reference Cross-reference: See also ss. Trans 305.17 and 305.37, Wis. adm. code.

347.37 347.37 Brake fluid, sale regulation.

347.37(1) (1) After January 1, 1960, no hydraulic brake fluid for use in motor vehicles shall be sold in this state if such brake fluid is below the minimum standard of specifications established by the society of automotive engineers for heavy duty type brake fluid No. 70R1 or a later designator for an improved product.

347.37(2) (2) All manufacturers of brake fluids selling such fluids in Wisconsin shall state on the immediate containers in which such fluid is packaged that the fluid therein meets or exceeds the specifications under sub. (1).

347.38 347.38 Horns and warning devices.

347.38(1) (1) No person shall operate a motor vehicle upon a highway unless such motor vehicle is equipped with a horn in good working order and capable of emitting sound audible under normal conditions from a distance of not less than 200 feet, but no person shall at any time use a horn otherwise than as a reasonable warning or make any unnecessary or unreasonably loud or harsh sound by means of a horn or other warning device.

347.38(2) (2) Except as otherwise provided in this section, no vehicle shall be equipped with nor shall any person use upon a vehicle any siren or compression or exhaust whistle.

347.38(3) (3) Any vehicle may be equipped with a theft alarm signal device if such device is so arranged that it cannot be used by the driver as an ordinary warning signal.

347.38(4) (4) An authorized emergency vehicle shall be equipped with a siren, but such siren shall not be used except when such vehicle is operated in response to an emergency call or in the immediate pursuit of an actual or suspected violator of the law, when responding to but not upon returning from a fire alarm, when transporting an organ for human transplantation, or when transporting medical personnel for the purpose of performing human organ harvesting or transplantation immediately after the transportation, in which events the driver of such vehicle shall sound the siren when reasonably necessary to warn pedestrians and other drivers.

347.38 Cross-reference Cross-reference: See also ss. Trans 305.25 and 305.41, Wis. adm. code.

347.38 History History: 2007 a. 20.

347.385 347.385 Traffic control signal preemption and priority devices.

347.385(1m) (1m) In this section:

347.385(1m)(a) (a) “Authorized emergency vehicle” means an authorized emergency vehicle as defined in s. 340.01 (3) (a), (c), (g), or (i).

347.385(1m)(d) (d) “Political subdivision” means a county, city, village, or town.

347.385(1m)(e) (e) “Snow removal vehicle” means any vehicle equipped with a snowplow or anti-icing equipment that is used by a political subdivision for snow removal and is operated by a political subdivision or the agent or lessee of a political subdivision.

347.385(1m)(f) (f) “Traffic control signal preemption device” means a device, located on or within a traffic control signal, that is designed to receive an electronic, radio, light, or sound transmission from an approaching vehicle that alters the normal sequence of the traffic control signal to provide or maintain a green signal for the vehicle to proceed through the intersection.

347.385(1m)(g) (g) “Traffic control signal priority device” means a device, located on or within a traffic control signal, that is designed to receive an electronic, radio, light, or sound transmission from an approaching vehicle to request that a green signal be provided or maintained for the vehicle to proceed through the intersection.

347.385(1m)(i) (i) “Transmitter” means a device that emits a signal for the purpose of activating a traffic control signal preemption device or a traffic control signal priority device.

347.385(2m) (2m) An authorized emergency vehicle may be equipped and operated with lamps designed and used, or with any other transmitter designed and used, to activate traffic control signal preemption devices.

347.385(2r) (2r) A snow removal vehicle equipped with oscillating, rotating, or flashing lights that is actively engaged in snow removal activities may be equipped and operated with lamps designed and used, or with any other transmitter designed and used, to activate traffic control signal priority devices.

347.385(3m) (3m) The lamps authorized for use under this section may be any color and may be flashing, oscillating, rotating or pulsating.

347.385(4) (4) No operator of an authorized emergency vehicle may use a transmitter, including lamps under sub. (2m), except when responding to an emergency call, when pursuing an actual or suspected violator of the law, or when responding to, but not when returning from, a fire alarm.

347.385(5) (5) 

347.385(5)(a) (a) No person may operate upon a highway a motor vehicle, other than an authorized emergency vehicle or snow removal vehicle, that is equipped with a transmitter or in which a transmitter is located. This subsection does not apply to a motor carrier or person in the business of selling transmitters to authorized users who transports a transmitter in original, unopened packaging or in an inoperative condition in an enclosed storage compartment of the vehicle.

347.385(5)(b) (b) No person may sell a transmitter except for use for authorized purposes as described in sub. (2m) or (2r).

347.385(6) (6) The authority responsible for maintenance of a traffic control signal may establish procedures for resolving conflicts between multiple requests for signal preemption or priority at a traffic signal, except that a signal preemption request from an authorized emergency vehicle must be given priority over any signal priority request.

347.385 History History: 2005 a. 193 ss. 1 to 6; Stats. 2005 s. 347.385; 2023 a. 167.

347.39 347.39 Mufflers.

347.39(1) (1) No person shall operate on a highway any motor vehicle subject to registration unless such motor vehicle is equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise or annoying smoke. This subsection also applies to motor bicycles.

347.39(2) (2) No muffler or exhaust system on any vehicle mentioned in sub. (1) shall be equipped with a cutout, bypass or similar device nor shall there be installed in the exhaust system of any such vehicle any device to ignite exhaust gases so as to produce flame within or without the exhaust system. No person shall modify the exhaust system of any such motor vehicle in a manner which will amplify or increase the noise emitted by the motor of such vehicle above that emitted by the muffler originally installed on the vehicle, and such original muffler shall comply with all the requirements of this section.

347.39(3) (3) In this section, “muffler” means a device consisting of a series of chambers of baffle plates or other mechanical design for receiving exhaust gases from an internal combustion engine and which is effective in reducing noise.

347.39 History History: 1983 a. 243.

347.39 Cross-reference Cross-reference: See also ss. Trans 305.20 and 305.39, Wis. adm. code.

347.40 347.40 Mirrors.

347.40(1) (1) No person shall operate any motor vehicle upon a highway unless such vehicle is equipped with a mirror so located as to reflect to the operator a view of the roadway for a distance of 200 feet to the rear of such vehicle.

347.40(2) (2) No person shall operate on a highway any school bus having a passenger-carrying capacity of 10 or more persons including the operator unless such bus is equipped with at least one mirror which is 7 inches in diameter so located as to enable the operator to see a reflection of the road from the entire front bumper forward to a point where direct observation is possible.

347.40(3) (3) No person may operate or permit the operation of any motor bus on a highway unless the bus is equipped with 2 outside rearview mirrors, one to the right and one to the left of the operator. Each mirror shall have not less than 50 square inches of unobstructed reflective surface and shall be firmly supported and adjustable to give the operator a clear view past both the right and left rear of the bus.

347.40 History History: 1975 c. 84; 1987 a. 235.

347.40 Cross-reference Cross-reference: See also ss. Trans 305.26 and 305.44, Wis. adm. code.

347.41 347.41 Speed indicators. No person shall operate on a highway any motor vehicle primarily designed for use upon a highway unless such motor vehicle is equipped with a speedometer which with reasonable accuracy registers the speed of the vehicle, except that motor trucks or truck tractors may be equipped with tachometers or any other devices that indicate speed and motor vehicles transported pursuant and in compliance with s. 341.47 (1) (b) and (c) may be equipped with a governor of speed of a type which restricts speed and which is set at a level equal to or below the limits of 55 miles per hour in lieu of a speedometer.

347.41 History History: 1983 a. 54.

347.41 Cross-reference Cross-reference: See also s. Trans 305.18, Wis. adm. code.

347.413 347.413 Ignition interlock device tampering; failure to install.

347.413(1) (1) No person may remove, disconnect, tamper with, or otherwise circumvent the operation of an ignition interlock device installed in response to the court order under s. 346.65 (6), 1999 stats., or s. 343.301 (1), 2007 stats., or s. 343.301 (1g), or fail to have the ignition interlock device installed as ordered by the court, or violate a court order under s. 343.301 (1g) restricting the person’s operating privilege. This subsection does not apply to the removal of an ignition interlock device upon the expiration of the order requiring the motor vehicle to be so equipped or to necessary repairs to a malfunctioning ignition interlock device by a person authorized by the department.

347.413(3) (3) The department shall design a warning label which shall be affixed to each ignition interlock device upon installation. The label shall provide notice of the penalties for tampering with or circumventing the operation of the ignition interlock device under sub. (1) and s. 343.10 (5) (a) 3.

347.413 History History: 1991 a. 277; 1993 a. 213; 1999 a. 109; 2001 a. 16 ss. 3445f, 3445g, 4060hd, 4060hw, 4060hy; 2009 a. 100, 121; 2017 a. 124.

347.415 347.415 Odometer tampering.

347.415(1g) (1g) In this section, “odometer” means an instrument for measuring and recording the actual distance that a motor vehicle, snowmobile, all-terrain vehicle, or utility terrain vehicle has traveled while in operation, but does not include any auxiliary instrument designed to be reset to zero to measure and record the actual distance that a motor vehicle, snowmobile, all-terrain vehicle, or utility terrain vehicle has traveled on trips.

347.415(1m) (1m) No person may, either personally or through an agent, remove, replace, disconnect, reset, tamper with, alter, or fail to connect the odometer of any motor vehicle, snowmobile, all-terrain vehicle, or utility terrain vehicle with the intent to change or affect the number of miles indicated thereon.

347.415(2) (2) No person may operate a motor vehicle subject to registration under ch. 341 on any street or highway with knowledge that the odometer is removed, disconnected or nonfunctional. An exemption may be provided if parts are on back order to correct a nonfunctional odometer.

347.415(3) (3) No person may advertise for sale, sell, use, install, or have installed any device which causes an odometer to register any mileage other than the true mileage driven. For purposes of this subsection, “true mileage driven” means that mileage traveled by the vehicle as measured and recorded by the odometer within the manufacturer’s design tolerance.

347.415(4) (4) No person shall conspire with any other person to violate sub. (1m), (2) or (3).

347.415(5) (5) Nothing in this section shall prevent the service, repair or replacement of an odometer, provided the mileage indicated thereon remains the same as before the service, repair or replacement. Where the odometer is incapable of registering the same mileage as before such service, repair or replacement, the odometer shall be adjusted to read zero, and a written notice shall be attached, by the owner or an agent, to the left door frame of the vehicle, or other location as prescribed by the department, specifying the mileage prior to service, repair or replacement of the odometer and the date on which it was serviced, repaired or replaced. No person may, with intent to defraud, remove or alter such a notice so affixed. No person who services, repairs or replaces an odometer that is incapable of registering the same mileage as before such service, repair or replacement may fail to adjust the odometer to read zero or fail to attach the notice required by this subsection.

347.415 History History: 1975 c. 121, 199; 1977 c. 29 s. 1654 (7) (a); 1993 a. 159; 2003 a. 166; 2011 a. 208.

347.415 Cross-reference Cross-reference: See also ch. Trans 154, Wis. adm. code.

347.417 347.417 Immobilization device tampering.

347.417(1) (1) No person may remove, disconnect, tamper with, or otherwise circumvent the operation of any immobilization device installed in response to a court order under s. 346.65 (6), 1999 stats., or s. 343.301 (2), 2007 stats. This subsection does not apply to the removal of an immobilization device pursuant to a court order or to necessary repairs to a malfunctioning immobilization device.

347.417(2) (2) The department shall design a warning label which shall be affixed by the owner of each immobilization device before the device is used to immobilize any motor vehicle under s. 346.65 (6), 1999 stats., or s. 343.301 (2), 2007 stats. The label shall provide notice of the penalties for removing, disconnecting, tampering with, or otherwise circumventing the operation of the immobilization device.

347.417 History History: 1991 a. 277; 1999 a. 109; 2001 a. 16 ss. 3445h to 3445m, 4060hg, 4060hj, 4060hw, 4060hy; 2009 a. 100.

347.42 347.42 Windshield wipers. No person may operate on a highway any motor vehicle equipped with a windshield, except a moped or motorcycle, unless the motor vehicle also is equipped with a device for cleaning rain, snow or other moisture from the windshield. The device shall be so constructed as to be controlled or operated by the operator of the vehicle and shall at all times be maintained in good working order.

347.42 History History: 1979 c. 163; 1983 a. 243; 1985 a. 65; 2019 a. 50.

347.42 Cross-reference Cross-reference: See also s. Trans 305.35, Wis. adm. code.

347.43 347.43 Safety glass.

347.43(1g) (1g) In this section, “safety glass” means glass so treated or combined with other materials as to reduce, in comparison with ordinary sheet glass or plate glass, the likelihood of injury to persons by objects from external sources or by such glass when it is struck, cracked or broken.

347.43(1s) (1s) No person may operate upon a highway any motor vehicle manufactured after January 1, 1936, except a recreational vehicle other than a 5th-wheel recreational vehicle, unless the motor vehicle is equipped with safety glass wherever glass is used on the motor vehicle in partitions, doors, windows or windshields.

347.43(2) (2) No person may sell any new motor vehicle unless such vehicle is equipped with safety glass in accordance with the requirements of sub. (1s).

347.43(4) (4) If a common carrier or person operating under a permit or certificate issued by the department is convicted of operating a vehicle in violation of this section, the department may suspend or revoke the permit or certificate until such time as the vehicle has been equipped with safety glass as required by this section.

347.43 History History: 1977 c. 29 s. 1654 (9) (f); 1981 c. 347; 1985 a. 187; 1993 a. 16; 1999 a. 85; 2007 a. 60.

347.43 Cross-reference Cross-reference: See also ss. Trans 305.32 and 305.34, Wis. adm. code.

347.43 Annotation Sub. (1) [now sub. (1s)] requires that whenever broken glass is replaced in a vehicle it must be replaced with safety glass. Replacing glass with plastic violated this section, and an officer observing a vehicle with replacement plastic had probable cause to stop the vehicle for a violation of this section. State v. Longcore, 2001 WI App 15, 240 Wis. 2d 429, 623 N.W.2d 201, 00-1171.

347.435 347.435 Vehicle monitoring and feedback. Notwithstanding s. 346.88, a person may operate a vehicle that has a device mounted to the front windshield if all of the following apply:

347.435(1) (1) The device is designed to monitor the vehicle and provide feedback to the operator for the purpose of safety or improving vehicle operation.

347.435(2) (2) The device is mounted directly above, behind, or below the mirror required in s. 347.40 (1) or, if no mirror is present, at the location where the mirror would typically be mounted.

347.435(3) (3) The device is mounted in a manner consistent with applicable federal requirements if the vehicle is a commercial motor vehicle as defined in 49 CFR 390.5.

347.435 History History: 2015 a. 160.