Window Tint – Can You See Me Now?

Q: Is it legal in Washington to have windows so dark that cross traffic cannot see the driver’s face? I have had two incidents where a car has pulled out in front of me where a near crash situation would have been avoided had I been able to see if the driver had looked my way.

A: I know someone who bought a car with tint so dark he had to drive with the windows down at night. Not a joke. He promptly removed the tint, both for functionality and legality. There are limits to window tint, both for safe driving and the law.

The Federal Motor Vehicle Safety Standards limit window tint to 70 percent transmission (the percent of light that passes through a window) for “glazing areas requisite for driving visibility.” And which glazing areas are requisite? Generally, it’s the windshield and the front windows.

When you buy a new car, that’s the rule vehicle sellers have to follow. Practically speaking, all windows in new vehicles have some reduction in light transmission. This small amount of tint helps to reduce glare and UV exposure. If you take a close look at your windows, you’ll notice a slight reduction in light compared to having your window open.

The federal rules apply to businesses that sell and repair vehicles, but not to individual car owners. That’s covered by state laws, and they vary from state to state. No state allows tinting of the windshield lower than the federal standard. Front windows range from no additional tint to as dark as 20 percent transmission, and in some states there’s no limit to how dark you can tint your rear windows.

In Washington, the transmission limit is 24 percent for all windows (except the windshield, of course). At that tint level you might not be able to see a driver’s face. It depends on where you, the sun, and the driver are, in relation to each other. Given the limited number of ways that road users can communicate with each other, being able to see and acknowledge each other is important. Go too dark with your tint and you give that up. A driver might not even notice the problem because they can see other drivers, cyclists, and pedestrians. But those people can’t see the person behind the dark window tint.

And what about overall visibility? Studies have found that – big surprise – it’s harder to see through darker tint. During the daytime the effect is minimal and primarily affects older drivers; even with 20/20 vision our ability to see contrast decreases as we age. For young drivers, tints as low as 35 percent transmission may not be problematic. At night though, “The adverse effects of window tinting become increasingly pronounced as transmittance goes below 70 percent.” Of course it does. Sunglasses are fine in bright light, but we don’t drive around in the dark with them on. Tinted windows are like sunglasses for your car, but you can’t take them off at night.

For anyone considering tinting their own windows, remember that earlier detail about windows coming from the factory with a bit of tint. If you applied film with 24 percent transmission on windows that already have 80 percent transmission (and why would you, knowing what you know now), you’ll end up darker than what’s legal.

The law permits 24 percent tint, but all the evidence indicates that you’re giving up too much visibility before you ever get to that number. If seeing clearly while driving is important to you (and it should be), Washington’s legal maximum tint is too dark.