All states have traffic laws that limit the amount of window tint on motor vehicles—often by specifying the amount of visible light transmission (VLT) that is required. VLT is the amount of light that is transmitted through the window and into the vehicle. For example, a 70%VLT means that 70% of light will pass through the window and 30% will be reflected. Thus, a lower VLT indicates a darker film or tint.

Another term to know is visual light reflection (VLR)—which is the opposite of VLT. VLR is the amount of solar energy that is reflected off the glass and away from the inside of the vehicle.

In most states tickets or citations for illegal window tint are known as fix-it tickets and the ticket or citation will indicate that it is a correctable violation of traffic laws. For example, if you fix the window tint problem within the required period, pay a small fine, and get the signature of an authorized person (a local police officer) the court may dismiss the ticket.

But if you fail to fix the window tint problem within the required period you must pay the fine for the violation and you may be issued another ticket that will be part of your driving record. And if you fail to pay the ticket or appear in court on the hearing date the court may issue a warrant for your arrest.

Window tint laws vary from state to state and some states have exemptions for certain vehicles such as limousines and recognize medical exemptions when the driver has a written statement from a licensed medical doctor, ophthalmologist, or optometrist.

In Hawaii, traffic laws regulate the amount of window tint on motor vehicles by specifying the required amount of visible light transmission (VLT). Hawaii law mandates that the front side windows must allow more than 35% of light in. The back side and rear windows may have a lower VLT, allowing for darker tint. The VLT for the rear windows must be over 35% if the vehicle does not have rearview mirrors on both sides; otherwise, any darkness can be used. The state also measures visual light reflection (VLR), and the front and back side windows must not reflect more than 35% of light. Hawaii offers medical exemptions for those who require less light exposure due to medical conditions, and these individuals must carry documentation from a licensed physician. Violations of window tint laws are typically considered 'fix-it' tickets, which are correctable violations. If corrected within a specified period, and after paying a fee and obtaining an authorized signature, the ticket may be dismissed. Failure to comply can result in fines, additional tickets, and potentially a warrant for arrest if court directives are ignored.