Wisconsin Windshield Mounting Laws

Wisconsin allows dashcams, GPS units, and phone mounts on the windshield. Wis. Stat. 346.88(3)(b) prohibits any object that obstructs the driver's clear view, so position your device behind the rearview mirror or in a lower windshield corner to stay compliant.

Wisconsin regulates windshield obstructions through Wis. Stat. 346.88, which covers obstruction of the operator's view and driving mechanism, and Wisconsin Administrative Code Trans 305.34, which sets the equipment standard for windshield tinting. No statute names GPS units or phone holders, but Wis. Stat. 347.435 does name one category of windshield-mounted device and expressly permits it.

This guide explains what you can and cannot mount on your windshield in Wisconsin, the tinting rules, how the state's distracted driving laws affect device use, and the penalties for violations.

Wisconsin Windshield Obstruction Law (Wis. Stat. 346.88)

The primary statute governing windshield-mounted devices is Wis. Stat. 346.88. This statute contains multiple provisions that regulate what can be placed on or near the windshield.

Prohibited Materials on the Windshield

Under subsection (3)(a), no person shall drive any motor vehicle with any sign, poster, or other nontransparent material upon the front windshield, front side wings, side windows in the driver's compartment, or rear window. The only exception is a certificate or other sticker issued by order of a governmental agency, which must not exceed 15 square inches and must be placed in the lower left corner of the windshield.

Objects Obstructing the Driver's View

Under subsection (3)(b), no person shall drive any motor vehicle upon a highway with any object so placed or suspended in or upon the vehicle so as to obstruct the driver's clear view through the front windshield.

This is the provision most relevant to phone mounts, GPS devices, and dashcams. The legal test is whether the object obstructs the driver's clear view. A small device positioned in a corner of the windshield that does not block the driver's line of sight is generally permissible.

The Wisconsin Supreme Court construed both subsections in State v. Houghton, 2015 WI 79, 364 Wis. 2d 234, 868 N.W.2d 143, which appears as the official annotation to the statute. The court read subsection (3)(a) to prohibit only the attachment of signs, posters, and other items of a similar nature to the front windshield, and held that subsection (3)(b) requires a material obstruction, even if minor. Under that reading, an object that is visible somewhere in the driver's field of view does not automatically violate the statute.

Additional Provisions

• Loading and passengers: A vehicle cannot be loaded or contain passengers positioned in a way that obstructs the driver's forward or side vision or interferes with control of the vehicle (subsection 1).

• Passenger positioning: No person shall ride in a position that interferes with the operator's visibility or control (subsection 2).

• Rear window obstructions: If the rear window is obstructed by a load, the vehicle must have an approved outside rearview mirror on each side meeting the requirements of Wis. Stat. 347.40 (subsection 3(c)).

• Emergency vehicle exemption: Signal lamps on authorized emergency vehicles are exempted from these restrictions (subsection 3(d)).

• Clean windshield requirement: Windshields, side wings, and windows must be maintained in a reasonably clean condition at all times (subsection 4).

Statutory Exception for Vehicle Monitoring Devices (Wis. Stat. 347.435)

Wis. Stat. 347.435, created by 2015 Wisconsin Act 160, is the one Wisconsin statute that addresses a windshield-mounted device directly. It provides that notwithstanding s. 346.88, a person may operate a vehicle with a device mounted to the front windshield if all of the following apply:

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

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

3. If the vehicle is a commercial motor vehicle as defined in 49 CFR 390.5, the device is mounted in a manner consistent with applicable federal requirements.

This covers safety cameras, telematics units, and driver-feedback devices of the kind used in commercial and fleet vehicles. It does not reach an ordinary phone mount or a standalone GPS receiver, which remain governed by the general obstruction test in 346.88(3)(b). What the exception does establish is that the area directly above, behind, or below the rearview mirror is the one windshield placement Wisconsin has affirmatively approved by statute.

Penalties for Obstruction Violations

Violating Wis. Stat. 346.88 is a traffic forfeiture. Under Wis. Stat. 346.95(1), fines range from $20 to $40 for a first offense ($50 to $100 for a repeat offense within a year), depending on the specific violation and whether it contributed to an accident. Court costs and surcharges are added to the base fine.

If a windshield obstruction contributes to an accident, the driver may face additional civil liability. An obstruction that causes or contributes to a crash strengthens negligence claims in lawsuits and can result in elevated charges.

Wisconsin Windshield Tinting Rules

Wisconsin's window tinting rules are split between two administrative code sections. Trans 305.34 governs windshields, and Trans 305.32 governs vent, side, and rear windows. Both apply to motor vehicles operated on Wisconsin highways.

Windshield Tint Requirements

Wisconsin is stricter than many states on windshield tinting. If the manufacturer did not affix an AS-1 line marking to the windshield, no aftermarket tinting film may be applied to the windshield at all. This effectively prevents drivers with older or replacement windshields from adding any tint.

Other Window Tint Limits

Wisconsin law also includes a 3% tolerance for law enforcement when measuring total light transmittance. An officer testing your windows with a light meter will allow up to 3% below the stated minimum before issuing a citation.

Reflectivity Rules

Tinting films on all windows must not be reflective. Wisconsin prohibits any metallic or mirrored appearance on vehicle windows. The combination of the glazing and tinting film must permit passage of the minimum VLT percentage while remaining non-reflective.

Side Mirror Requirement

If any rear window does not transmit at least 60% of visible light, the vehicle must be equipped with an outside rearview mirror on both the left and right side of the driver's compartment.

Medical Exemptions

Trans 305.32 provides a medical exception for the front side windows. On the recommendation of a physician or a Christian Science practitioner treating the vehicle owner, or an immediate family member of the owner, the front side windows may be tinted to permit passage of at least 35% of visible light instead of the usual 50%.

The rule attaches a documentation condition. A written statement from the treating physician or practitioner that identifies the patient, the medical condition justifying the recommendation, whether the condition is temporary or permanent, and the vehicle it applies to (make, model, year, and vehicle identification number) must be carried in the vehicle at all times.

Penalties for Tint Violations

Window tint violations in Wisconsin are treated as equipment violations. Under Trans 305.04, a violation of ch. Trans 305 is punishable as prescribed in Wis. Stat. 110.075(7), a forfeiture of not less than $10 nor more than $200, plus court costs and surcharges. Drivers may be required to remove non-compliant tinting material and present the vehicle for reinspection.

GPS and Navigation Device Mounts

Wisconsin permits GPS and navigation devices to be mounted on the windshield. The key legal requirements are:

1. The device must not obstruct the driver's view. Position the mount so it does not block your line of sight to the road, traffic signals, or pedestrians.

2. The mount cannot be classified as a sign, poster, or nontransparent material. Under Wis. Stat. 346.88(3)(a), these are prohibited on the windshield. A transparent suction cup mount with a small device attached is not considered a "sign" or "poster" under the statute, but the device itself is an "object" governed by subsection (3)(b).

3. You should not interact with the device in ways that constitute inattentive driving. Under Wis. Stat. 346.89(1), any activity other than driving that interferes with the ability to drive safely is prohibited.

Best Placement Practices

For legal compliance, mount GPS devices in these locations:

• Behind the rearview mirror, if the device is small enough not to extend beyond the mirror's profile. This is the same zone Wis. Stat. 347.435 designates for vehicle monitoring devices
• On the dashboard, using a dashboard mount or friction pad, which avoids the windshield obstruction question entirely
• Lower corner of the windshield (driver or passenger side), below the line of sight to the road ahead

Avoid mounting a GPS in the center of the windshield at eye level. While not explicitly banned by statute, this placement creates the strongest argument for an obstruction citation.

Phone Use and Distracted Driving Laws

Wisconsin's distracted driving laws are contained in Wis. Stat. 346.89. Unlike states with comprehensive hands-free laws, Wisconsin does not prohibit all handheld phone use for adult drivers. Instead, the state has targeted restrictions.

What Wis. Stat. 346.89 Prohibits

• Texting while driving (all drivers): No person may drive any motor vehicle while composing or sending an electronic text message or electronic mail message. Using a voice-operated or hands-free feature that does not require the use of hands (except for a single activation touch) is permitted.

• Phone use in construction zones: No person may drive while using a cellular or wireless telephone in a highway maintenance or construction area where workers are at risk from traffic. An exception exists for reporting emergencies and for using voice-operated or hands-free devices.

• All phone use by novice drivers: No person holding a probationary license or instruction permit may drive while using a cellular or wireless telephone, except to report an emergency. This is a complete ban on phone use, including hands-free, for new drivers.

• Inattentive driving (general): No person shall be engaged or occupied with an activity, other than driving the vehicle, that interferes or reasonably appears to interfere with the person's ability to drive safely.

How Phone Mounts Help Wisconsin Drivers

Although Wisconsin does not require hands-free phone use for adult drivers making voice calls, a phone mount is still beneficial:

• It keeps the phone visible for navigation without holding it
• It reduces the temptation to hold the phone, which could trigger an inattentive driving citation
• It positions the phone for voice-activated texting, which is the only legal way to text while driving
• It provides a secure location for the phone in construction zones where hands-free use is required

Penalties for Distracted Driving Violations

Wisconsin's work zone doubling provision, Wis. Stat. 346.60(3m), doubles the forfeitures for speed restriction violations under Wis. Stat. 346.57. It does not double a distracted driving forfeiture. Court costs and surcharges are added to the base fine.

Dashcam Rules in Wisconsin

Wisconsin has no statute that uses the word dashcam. A consumer dashcam is treated the same as any other windshield-mounted object under the general obstruction statute. A safety or driver-feedback camera that monitors the vehicle and reports to the operator can instead fall inside the Wis. Stat. 347.435 exception when it is mounted in the mirror zone.

Legal Requirements for Dashcams

• The dashcam must not obstruct the driver's clear view through the front windshield (Wis. Stat. 346.88(3)(b))
• The dashcam must not be classified as nontransparent material covering a significant windshield area (Wis. Stat. 346.88(3)(a))
• Interacting with the dashcam while driving must not constitute inattentive driving (Wis. Stat. 346.89)

Recommended Dashcam Placement

The safest legal placement for a dashcam in Wisconsin is behind the rearview mirror, which is also the zone named in Wis. Stat. 347.435, where the camera has a clear view of the road ahead without blocking the driver's line of sight. Small, compact dashcams that fit within the profile of the rearview mirror area are the least likely to draw a citation.

Dashboard-mounted dashcams are also permitted and avoid windshield obstruction concerns entirely.

Audio Recording Considerations

Wisconsin is a one-party consent state for audio recordings. As the vehicle owner and operator, you can legally record conversations inside your own vehicle without notifying passengers. However, it is good practice to inform passengers that a dashcam with audio recording is in use.

Stickers, Decals, and Required Items

Under Wis. Stat. 346.88(3)(a), the only items permitted to be affixed to the windshield are certificates or stickers issued by order of a governmental agency. These must not exceed 15 square inches and must be placed in the lower left corner of the windshield.

Examples of permitted stickers include:

• Vehicle registration stickers (where required)
• Emissions inspection stickers
• Toll transponder tags
• Parking permits issued by government agencies

Non-governmental stickers, decals, and parking passes should not be placed on the windshield. Place them on the dashboard or use a clip on the sun visor instead.

Windshield Damage and Replacement

Wisconsin law requires that windshields be maintained in reasonably clean and unobstructed condition. While the statute does not specify exact crack dimensions, enforcement follows these general principles:

When Windshield Damage May Result in a Citation

• Cracks or chips in the driver's direct line of sight
• Extensive cracking that distorts visibility
• Multiple cracks or chips that collectively impair the view
• Damage combined with dirt or debris that worsens visibility

When Damage Is Typically Allowed

• Small chips outside the driver's line of sight
• Minor cracks that do not extend into the driver's viewing area
• Damage on the passenger side that does not affect the driver's vision

Summary of Wisconsin Windshield Laws

More Wisconsin Laws

• Wisconsin Lemon Law
• Wisconsin Car Seat Laws
• Wisconsin Sexting Laws
• Wisconsin Statute of Limitations