Aren’t drivers supposed to have a clear view out the rear window of their car? I saw someone driving with their entire back window covered in snow. The inability to see behind you is a serious safety issue. They drove past a police car and the officer didn’t do anything. Even if they’re not breaking the law, if I were that officer, I’d have at least pulled them over and told them they should clean the snow off.

A: Snow blocking your view is a problem. But I want to address your proposed violation of a driver’s rights. Let’s pretend for a moment that driving with an entire back window covered in snow is not prohibited by law. The police can’t make a traffic stop just because they don’t like something about the driver’s vehicle.

Consider lifted pickups. Lift kits and bigger tires are great for off-roading, but empirically worse for driving on streets. The “worse” list includes decreased handling, increased stopping distance, greater roll-over risk and reduced pedestrian visibility. Yet it’s legal to jack up your pickup. Should officers be allowed to pull over pickup drivers because they know lifted trucks are less safe? There’s an argument to be made that vehicle modifications should only be allowed if they’ve been engineered to meet the original safety standards, but that’s not the law.

In a society that values freedom, limitations on police powers are part of the package. The Revised Code of Washington has a long list of things worthy of a traffic stop, and they can be mostly summarized in four categories:An officer knows that you’re not licensed to drive.

An officer observes an equipment or vehicle licensing violation, like a burned-out headlight or expired tabs.

An officer observes you violating traffic law.

An officer has reasonable suspicion to believe that you or someone in your car committed a crime.

But your question is really about snow on a window. The law is clear (even if the window isn’t); no person shall drive a motor vehicle with any nontransparent material on a window that obstructs the driver’s clear view. The same law that requires drivers to secure their load also requires drivers to remove any debris from the vehicle before driving. If any of that debris (like chunks of ice) flies off and injures someone or causes damage, it moves from a traffic infraction to a crime.

Visibility is fundamental to driving, and snow flying off your car is no joke. To anyone who needs to hear this, take a couple extra minutes on frosty or snowy days to make sure all your windows are clear.

Doug Dahl writes a weekly traffic safety column for this newspaper. He is with the state Traffic Safety Commission.