Hawaii Windshield Mounting Laws (2026 Guide)

Hawaii does not have a statute that specifically addresses windshield-mounted dashcam, GPS, or phone mounts. HRS 291C-124 is a narrow statute reaching vehicle loading, more than three front-seat passengers, and objects in the driver's lap or immediate area that interfere with the driving mechanism, and it contains no general unobstructed-view clause that reaches a mounted device. What does turn on a mount is Hawaii's statewide hands-free law, HRS 291C-137, which defines using a mobile electronic device as holding it while driving. A phone in a windshield or dashboard mount is not being held, and that is precisely why mounting it keeps in-car phone use lawful in Hawaii.

Hawaii regulates windshield-mounted devices and materials through three statutes that matter here. HRS 291-21.5 governs sun screening devices and nontransparent materials on windshields. HRS 291C-124 addresses obstructions to the driver's view and driving mechanism, though on much narrower terms than its title suggests. HRS 291C-137 is the statewide hands-free law, and it is the provision that actually answers the practical question of whether you can mount and use a phone in the car.

This page covers Hawaii's rules for GPS mounts, phone holders, dashcams, stickers, windshield tinting, and the significant changes introduced by Act 129 in 2025.

Hawaii Windshield Obstruction Law (HRS 291C-124)

HRS 291C-124 is titled "Obstruction to driver's view or driving mechanism," but its operative text is far narrower than the title implies, and reading the title alone is the most common way this statute gets misapplied to mounted devices.

Subsection (a) prohibits driving a vehicle only when it is "so loaded," or when there are more than three persons in the front seat, in a way that obstructs the driver's view to the front or sides or interferes with control over the driving mechanism. Subsection (b) prohibits holding in your lap, or allowing in your immediate area, any person, animal, or object that interferes with control over the driving mechanism. Note that subsection (b) is about the driving mechanism only, not about the view. Subsection (c) governs where passengers may ride.

None of the three prongs reaches a camera or phone cradle attached to the glass. A windshield mount is not vehicle loading, not a front-seat passenger, and does not interfere with the steering, pedals, or shifter. Hawaii has no residual clause of the kind several other states use, requiring that the driver's view through required glass equipment be unobstructed, so there is no general Hawaii prohibition that a mount can be measured against.

Hawaii's windshield-specific rules for materials on the glass are set out separately in HRS 291-21.5, covered below.

Sticker and Decal Placement Zones

HRS 291-21.5 is a sun screening and glazing statute, and its subsection (e) exemptions include specific measurement zones for materials displayed on the windshield.

Subsection (e)(3) exempts signs, stickers, or other materials displayed in two designated areas:

These zones accommodate items such as vehicle registration decals, parking permits, safety inspection stickers, and toll transponders. Note that the exemption is written as "signs, stickers, or other materials," not as decals alone.

Exempted Items

HRS 291-21.5(e) also exempts the following, among others:

• Rearview mirrors
• Adjustable nontransparent sun visors that are mounted forward of the side windows and not attached to the glazing material
• Transparent sun screening film applied along the top edge of the windshield, so long as it does not encroach on the AS-1 portion or extend lower than four inches below the top of the windshield
• Transparent sun screening materials applied to the AS-1 portion of the windshield that meet Federal Motor Vehicle Safety Standard 205
• Window wipers and wiper motors, rear trunk lid handles and hinges, and privacy drapes or blinds inside motor homes

GPS and Phone Mounts

Hawaii has no statute that specifically addresses GPS or phone mount placement on the windshield, unlike states such as Georgia or California that have enacted express device-mount exceptions.

That absence matters less than it sounds, because the prohibition a mount would have to clear does not exist. As explained above, HRS 291C-124 has no general view-obstruction prong that reaches a mounted device, and HRS 291-21.5 regulates glazing material and sun screening devices rather than hardware attached to the glass.

The one statutory geometry Hawaii does offer is the (e)(3) corner squares. Because that exemption covers "signs, stickers, or other materials" rather than decals specifically, a mount kept inside the 7-inch passenger-side square or the 5-inch driver-side square is arguably inside it. No Hawaii court decision or agency rule squarely resolves the question, so treat those squares as a conservative safe harbor rather than a settled allowance. In practice, mounting low on the windshield away from your direct line of sight, or on the dashboard, is the most defensible placement.

Statewide Hands-Free Law (HRS 291C-137)

Hawaii does have a statewide hands-free driving law, and it is the reason mounting a phone matters legally. HRS 291C-137(a) provides that no person shall operate a motor vehicle while using a mobile electronic device.

The definition in subsection (e) is the crux for anyone shopping for a mount: "use" or "using" means holding a mobile electronic device while operating a motor vehicle. A phone sitting in a windshield cradle or dashboard mount is not being held, so using it that way is not the conduct the statute bans. That is the practical answer to why drivers mount their phones in Hawaii.

A few details are worth knowing:

• Fine. Subsection (f) sets a $300 fine, rising to $400 if the violation occurs in a school zone or construction area. Subsection (g) makes it a traffic infraction.
• Drivers under 18. Subsection (c) is stricter for them: no one under eighteen may operate a vehicle while using even a hands-free mobile electronic device, except to make a 911 call. A mount does not cure that.
• Emergency calls. Subsection (b) makes a 911 emergency communication an affirmative defense.
• Exemptions. Subsection (d) exempts emergency responders on duty, certain two-way radio and amateur radio users, and drivers fully stopped with the engine off in a safe location off the roadway.
• County ordinances are superseded. Subsection (h) states that this section supersedes any county ordinance regulating the use or utilization of mobile electronic devices while operating a motor vehicle. Older Honolulu and Maui County handheld-device ordinances are not the operative rule; the state statute is. Drivers do not need to check island-by-island rules for handheld phone use.

Dashcam Mounting Rules

Hawaii does not have a statute specifically addressing dashcams, and HRS 291C-124 does not supply one for the reasons set out above: its view-obstruction prong is limited to vehicle loading and front-seat crowding, and its object prong requires interference with the driving mechanism. A camera clipped to the glass is neither.

A dashcam mounted behind the rearview mirror is still the most sensible placement. That position occupies space already blocked from the driver's primary line of sight and keeps the camera clear of the swept and inspected areas of the windshield.

Hawaii is a one-party consent state for audio recording under HRS 803-42, so a dashcam that records conversations inside the vehicle is legal as long as at least one person in the car is aware of the recording.

Windshield Tinting (HRS 291-21.5)

HRS 291-21.5 is primarily a tinting statute. It prohibits operating or parking a motor vehicle on a public highway if the glazing material does not meet Federal Motor Vehicle Safety Standard 205, or if the vehicle uses sun screening devices that fall outside the law's exemptions.

Current Tinting Requirements

Before Act 129 (2025), Hawaii's tinting rules required:

• Front windshield: Must allow at least 70% visible light transmission (VLT). This is essentially clear glass with no aftermarket tint permitted below the AS-1 line.
• Front side windows (driver and passenger): Must allow at least 35% VLT.
• Rear side windows: Must allow at least 35% VLT for sedans; SUVs, vans, and trucks had more lenient standards.
• Rear windshield: Must allow at least 35% VLT for sedans.

Act 129 (2025) Changes

Act 129 (2025) made the most significant changes to Hawaii's vehicular tinting laws since the statute was first enacted in 1983. The amendment appears in the statute's history note as am L 2025, c 129.

Key changes under Act 129 include the following.

Sedan rear window parity. Subsection (e)(9) now exempts rear windows, including the rear windshield, on sedans as well as vans, minivans, trucks, and buses, along with side windows to the rear of the driver, provided the vehicle has rearview mirrors on both sides. Previously, sedans were held to a stricter standard.

Traffic stop window requirement. New subsection (d) requires all drivers and passengers in vehicles with applied tint to fully roll down their windows when stopped by a law enforcement officer. An exception exists for individuals who cannot do so due to physical disability or mechanical failure, provided the driver communicates or cooperates through other reasonably available means. Failure to comply may be cited as a noncriminal traffic infraction.

Compliance certificate. The installer must issue a certificate to the vehicle owner at the time the sun screening device is installed, certifying that the device complies with law. The certificate must be stored in the vehicle at all times, and its absence at the time of citation is prima facie evidence of installer noncompliance.

Color restrictions. Subsection (b)(2) prohibits mirrored or high reflective finishes that produce a red, yellow, amber, or blue appearance as viewed from outside the vehicle.

Front windshield and front side windows. The 70% VLT expectation for the front windshield, which comes from FMVSS 205, and the 35% VLT standard for front side windows in subsections (e)(7) and (e)(8) were not loosened by Act 129. The changes apply primarily to rear windows on sedans.

No Medical Tint Exemption

Unlike many other states, Hawaii does not offer a medical exemption for darker windshield or window tinting. Drivers with medical conditions requiring protection from sunlight cannot obtain a waiver for non-compliant tinting. This was not changed by Act 129.

Drivers who need sun protection should use removable sun shades on rear windows (where darker tint is now permitted on all vehicle types) or consider vehicles with factory-tinted privacy glass that meets the VLT requirements.

Penalties for Violations

HRS 291-21.5(f) establishes a tiered penalty structure based on who is responsible for the tinting violation.

Violations of chapter 291C for which no other penalty is specified, including HRS 291C-124, are fined under HRS 291C-161(b): not more than $250 for a first violation, $300 for a second committed within one year of the first, and $500 for a third or subsequent violation within that year. These amounts are set by state statute, not by county.

Holding a phone while driving is penalized separately and more heavily. HRS 291C-137(f) sets a flat $300 fine, or $400 in a school zone or construction area.

Under Act 129, failure to roll down tinted windows during a traffic stop may be cited as a noncriminal traffic infraction under HRS 291-21.5(d).

Commercial Vehicles

Commercial vehicles operating in Hawaii must comply with both state windshield laws and Federal Motor Carrier Safety Regulations (49 CFR 393.60). Federal rules prohibit any obstruction that reduces the driver's field of view through required windows.

Commercial drivers should mount electronic logging devices (ELDs) and GPS units on the dashboard rather than the windshield to avoid potential federal violations during Department of Transportation inspections.

Safety Inspection and Windshields

Hawaii requires annual safety inspections for all registered vehicles, and HRS 291-21.5(c) requires that inspection to include a test that the glazing material and any sun screening devices meet the statute's requirements. The windshield is also checked for cracks, chips, and obstructions. A windshield with significant damage or non-compliant tinting will fail the inspection.

Recent Changes

Act 129 (2025) represents the most significant update to Hawaii's windshield and tinting statute in over 40 years. The key takeaways from this change are as follows.

Sedan owners now have the same tinting flexibility as SUV and truck owners for rear windows. All drivers with tinted windows have a new obligation to roll them down during traffic stops. Tint installers face stricter accountability through the compliance certificate requirement.

No changes to windshield device mounting practices were enacted by Act 129; the act's changes were limited to tinting under HRS 291-21.5.

More Hawaii Laws

• Hawaii Recording Laws
• Hawaii Lemon Laws
• Hawaii Hit and Run Laws
• Hawaii Car Seat Laws
• Hawaii Dog Bite Laws

Frequently Asked Questions

Can I mount a GPS or phone on my windshield in Hawaii?

Yes. Hawaii has no statute that specifically addresses windshield-mounted device placement, and the statute usually cited, HRS 291C-124, does not reach one: its view-obstruction prong applies only to vehicle loading or more than three front-seat passengers, and its object prong requires interference with the driving mechanism. Mounting a phone is in fact how you comply with Hawaii's hands-free law, because HRS 291C-137 defines using a device as holding it. The most defensible placement is low on the windshield away from your line of sight, or on the dashboard.

Does Hawaii have a statewide hands-free law?

Yes. HRS 291C-137(a) prohibits operating a motor vehicle while using a mobile electronic device, and subsection (e) defines use as holding the device while driving. The fine is $300, or $400 in a school zone or construction area. Subsection (h) supersedes any county ordinance on device use while driving, so the same rule applies on every island. Drivers under eighteen face a stricter rule and may not use even a hands-free device except to call 911.

Is it legal to use a dashcam in Hawaii?

Yes. There is no dashcam statute in Hawaii, and HRS 291C-124 does not reach a camera attached to the glass. Mounting behind the rearview mirror is recommended because that space is already outside the driver's primary line of sight. Hawaii is a one-party consent state for audio recording under HRS 803-42.

Where can I place stickers on my windshield in Hawaii?

HRS 291-21.5(e)(3) exempts signs, stickers, or other materials displayed in a 7-inch square in the lower passenger-side corner of the windshield, or in a 5-inch square in the lower driver-side corner. Those two squares are the designated zones.

Does Hawaii offer a medical exemption for darker window tint?

No. Hawaii does not provide a medical exemption for non-compliant window tinting. This was not changed by Act 129 in 2025. Drivers who need sun protection should use removable sun shades or vehicles with factory privacy glass.

What changed with Hawaii Act 129 (2025)?

Act 129 aligned sedan rear window and rear windshield tint rules with those for vans, trucks, and buses, added a requirement that drivers and passengers roll down tinted windows at a traffic stop, required installers to issue a compliance certificate that must be kept in the vehicle, and prohibited mirrored or high reflective finishes producing a red, yellow, amber, or blue appearance.