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 Maryland, window tint laws are designed to ensure that visibility through vehicle windows is not excessively restricted. Maryland law specifies that the front side windows must allow at least 35% of the light to pass through (35% VLT), while the back side windows and rear window can have any level of darkness if the vehicle has outside rearview mirrors on both sides. The windshield may have a non-reflective tint strip on the top 5 inches or down to the AS-1 line, whichever comes first. The VLT refers to the percentage of light allowed through the window, and a lower VLT means a darker tint. Maryland also regulates the VLR, which is the amount of light reflected by the tint; the front side windows must not reflect more than 35% of light. Maryland recognizes medical exemptions for individuals who require a lower VLT due to medical conditions, and these individuals must carry documentation from a licensed physician. Violations of the window tint laws can result in 'fix-it tickets,' which are correctable violations. If corrected within a specified period and verified by an authorized person, such as a police officer, the ticket may be dismissed upon payment of a small fine. Failure to correct the issue or to pay the fine can lead to additional penalties, including the possibility of a warrant for arrest if a court appearance is missed.