Q: Does a company that requires a right-turn-only out of its driveway or parking lot onto a public road need a permit to put up said sign? I feel like I’m being discriminated against because I live in the opposite direction.

A: Right about now all the people who have actually experienced discrimination because of race, gender, age or sexual orientation are playing the world’s smallest violins for you. Right-turn-only signs on private property are not discrimination. The real purpose is less insidious and more practical.

If your boss was the person who independently decided to put up a right-turn-only sign, that would be illegal. Law prohibits installing any unauthorized sign that looks like the real deal or attempts to direct the movement of traffic.

There’s a grocery store I frequent, and until recently I could make a left turn out of the parking lot. As development expanded, it became increasingly difficult, and risky, to make that turn. Once a giant box store went in across the street, left turns were no longer an option. A right-turn-only sign was installed. And to make sure it’s obeyed there is now a curb preventing drivers from crossing into the left-bound lane.

The grocery store manager didn’t choose to prohibit left turns. That decision was made by a traffic engineer. When developers propose projects that impact transportation infrastructure, the permit process includes a review of the road situation to see if the increased traffic will require modifications. Sometimes those modifications include changes to publicly accessible property that’s privately owned, like a grocery store or your place of employment.

Government can tell a private person or company to install a traffic control device on their property? As stated in the Manual on Uniform Traffic Control Devices (it’s like the Bible for road signs) the rules apply to all roads open to public travel, independent of whether it is public or private property.

Local ordinances may spell it out more clearly. As an example, Bellevue’s city code states, “Left turns to and from a private road may be restricted either at the time of development or in the future if such maneuvers are found by the city to be hazardous.” Your city probably has something similar.

And while we’re on the topic of left turns, we should probably try to avoid them when we can. A study by the National Highway Traffic Safety Administration found that in crashes where crossing or turning in an intersection was a factor, 62% of crashes involved a left-turning driver, while only 3% involved a right-turning driver.

Even if avoiding left turns is impractical, it’s good to keep in mind the additional risk. The No. 1 error in left-turn crashes is not paying attention. It’s not because those drivers had great observational skills but they let their guard down in the intersection. Instead, their habitually inadequate surveillance showed itself in a critical situation. By practicing good situational awareness whenever you’re driving, it’ll be there when you need it most.

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